regen is a tool to parse and generate random strings from regular expressions. regen works by parsing a regular expression and walking its op tree. It is currently not guaranteed to produce entirely accurate results, but will at least try. Currently, word boundaries are not supported (until I decide how best to randomly insert a word boundary character). Using a word boundary op (\b or \B) will currently cause regen to panic. In addition, line endings are also poorly supported right now and EOT markers are treated as the end of string generation. Usage is simple, pass one or more regular expressions to regen on the command line and it will generate a string from each, printing them in the same order as on the command line (separated by newlines): So, if you fancy yourself a Javascript weirdo of some variety, you can at least use regen to write code for eBay: A few command-line options are provided, which you can see by running regen -help.
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/robertkrimen/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/robertkrimen/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/robertkrimen/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/robertkrimen/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/robertkrimen/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Package gorilla/mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well:
Package gorilla/mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well:
Package skipper provides an HTTP routing library with flexible configuration as well as a runtime update of the routing rules. Skipper works as an HTTP reverse proxy that is responsible for mapping incoming requests to multiple HTTP backend services, based on routes that are selected by the request attributes. At the same time, both the requests and the responses can be augmented by a filter chain that is specifically defined for each route. Optionally, it can provide circuit breaker mechanism individually for each backend host. Skipper can load and update the route definitions from multiple data sources without being restarted. It provides a default executable command with a few built-in filters, however, its primary use case is to be extended with custom filters, predicates or data sources. For further information read 'Extending Skipper'. Skipper took the core design and inspiration from Vulcand: https://github.com/mailgun/vulcand. Skipper is 'go get' compatible. If needed, create a 'go workspace' first: Get the Skipper packages: Create a file with a route: Optionally, verify the syntax of the file: Start Skipper and make an HTTP request: The core of Skipper's request processing is implemented by a reverse proxy in the 'proxy' package. The proxy receives the incoming request, forwards it to the routing engine in order to receive the most specific matching route. When a route matches, the request is forwarded to all filters defined by it. The filters can modify the request or execute any kind of program logic. Once the request has been processed by all the filters, it is forwarded to the backend endpoint of the route. The response from the backend goes once again through all the filters in reverse order. Finally, it is mapped as the response of the original incoming request. Besides the default proxying mechanism, it is possible to define routes without a real network backend endpoint. One of these cases is called a 'shunt' backend, in which case one of the filters needs to handle the request providing its own response (e.g. the 'static' filter). Actually, filters themselves can instruct the request flow to shunt by calling the Serve(*http.Response) method of the filter context. Another case of a route without a network backend is the 'loopback'. A loopback route can be used to match a request, modified by filters, against the lookup tree with different conditions and then execute a different route. One example scenario can be to use a single route as an entry point to execute some calculation to get an A/B testing decision and then matching the updated request metadata for the actual destination route. This way the calculation can be executed for only those requests that don't contain information about a previously calculated decision. For further details, see the 'proxy' and 'filters' package documentation. Finding a request's route happens by matching the request attributes to the conditions in the route's definitions. Such definitions may have the following conditions: - method - path (optionally with wildcards) - path regular expressions - host regular expressions - headers - header regular expressions It is also possible to create custom predicates with any other matching criteria. The relation between the conditions in a route definition is 'and', meaning, that a request must fulfill each condition to match a route. For further details, see the 'routing' package documentation. Filters are applied in order of definition to the request and in reverse order to the response. They are used to modify request and response attributes, such as headers, or execute background tasks, like logging. Some filters may handle the requests without proxying them to service backends. Filters, depending on their implementation, may accept/require parameters, that are set specifically to the route. For further details, see the 'filters' package documentation. Each route has one of the following backends: HTTP endpoint, shunt or loopback. Backend endpoints can be any HTTP service. They are specified by their network address, including the protocol scheme, the domain name or the IP address, and optionally the port number: e.g. "https://www.example.org:4242". (The path and query are sent from the original request, or set by filters.) A shunt route means that Skipper handles the request alone and doesn't make requests to a backend service. In this case, it is the responsibility of one of the filters to generate the response. A loopback route executes the routing mechanism on current state of the request from the start, including the route lookup. This way it serves as a form of an internal redirect. Route definitions consist of the following: - request matching conditions (predicates) - filter chain (optional) - backend (either an HTTP endpoint or a shunt) The eskip package implements the in-memory and text representations of route definitions, including a parser. (Note to contributors: in order to stay compatible with 'go get', the generated part of the parser is stored in the repository. When changing the grammar, 'go generate' needs to be executed explicitly to update the parser.) For further details, see the 'eskip' package documentation Skipper has filter implementations of basic auth and OAuth2. It can be integrated with tokeninfo based OAuth2 providers. For details, see: https://godoc.org/github.com/zalando/skipper/filters/auth. Skipper's route definitions of Skipper are loaded from one or more data sources. It can receive incremental updates from those data sources at runtime. It provides three different data clients: - Kubernetes: Skipper can be used as part of a Kubernetes Ingress Controller implementation together with https://github.com/zalando-incubator/kube-ingress-aws-controller . In this scenario, Skipper uses the Kubernetes API's Ingress extensions as a source for routing. For a complete deployment example, see more details in: https://github.com/zalando-incubator/kubernetes-on-aws/ . - Innkeeper: the Innkeeper service implements a storage for large sets of Skipper routes, with an HTTP+JSON API, OAuth2 authentication and role management. See the 'innkeeper' package and https://github.com/zalando/innkeeper. - etcd: Skipper can load routes and receive updates from etcd clusters (https://github.com/coreos/etcd). See the 'etcd' package. - static file: package eskipfile implements a simple data client, which can load route definitions from a static file in eskip format. Currently, it loads the routes on startup. It doesn't support runtime updates. Skipper can use additional data sources, provided by extensions. Sources must implement the DataClient interface in the routing package. Skipper provides circuit breakers, configured either globally, based on backend hosts or based on individual routes. It supports two types of circuit breaker behavior: open on N consecutive failures, or open on N failures out of M requests. For details, see: https://godoc.org/github.com/zalando/skipper/circuit. Skipper can be started with the default executable command 'skipper', or as a library built into an application. The easiest way to start Skipper as a library is to execute the 'Run' function of the current, root package. Each option accepted by the 'Run' function is wired in the default executable as well, as a command line flag. E.g. EtcdUrls becomes -etcd-urls as a comma separated list. For command line help, enter: An additional utility, eskip, can be used to verify, print, update and delete routes from/to files or etcd (Innkeeper on the roadmap). See the cmd/eskip command package, and/or enter in the command line: Skipper doesn't use dynamically loaded plugins, however, it can be used as a library, and it can be extended with custom predicates, filters and/or custom data sources. To create a custom predicate, one needs to implement the PredicateSpec interface in the routing package. Instances of the PredicateSpec are used internally by the routing package to create the actual Predicate objects as referenced in eskip routes, with concrete arguments. Example, randompredicate.go: In the above example, a custom predicate is created, that can be referenced in eskip definitions with the name 'Random': To create a custom filter we need to implement the Spec interface of the filters package. 'Spec' is the specification of a filter, and it is used to create concrete filter instances, while the raw route definitions are processed. Example, hellofilter.go: The above example creates a filter specification, and in the routes where they are included, the filter instances will set the 'X-Hello' header for each and every response. The name of the filter is 'hello', and in a route definition it is referenced as: The easiest way to create a custom Skipper variant is to implement the required filters (as in the example above) by importing the Skipper package, and starting it with the 'Run' command. Example, hello.go: A file containing the routes, routes.eskip: Start the custom router: The 'Run' function in the root Skipper package starts its own listener but it doesn't provide the best composability. The proxy package, however, provides a standard http.Handler, so it is possible to use it in a more complex solution as a building block for routing. Skipper provides detailed logging of failures, and access logs in Apache log format. Skipper also collects detailed performance metrics, and exposes them on a separate listener endpoint for pulling snapshots. For details, see the 'logging' and 'metrics' packages documentation. The router's performance depends on the environment and on the used filters. Under ideal circumstances, and without filters, the biggest time factor is the route lookup. Skipper is able to scale to thousands of routes with logarithmic performance degradation. However, this comes at the cost of increased memory consumption, due to storing the whole lookup tree in a single structure. Benchmarks for the tree lookup can be run by: In case more aggressive scale is needed, it is possible to setup Skipper in a cascade model, with multiple Skipper instances for specific route segments.
Package restful, a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. The default router is the RouterJSR311 which is an implementation of its spec (http://jsr311.java.net/nonav/releases/1.1/spec/spec.html). However, it uses regular expressions for all its routes which, depending on your usecase, may consume a significant amount of time. The CurlyRouter implementation is more lightweight that also allows you to use wildcards and expressions, but only if needed. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to true, Route functions are responsible for handling any error situation. Default value is false; it will recover from panics. This has performance implications. SetCacheReadEntity controls whether the response data ([]byte) is cached such that ReadEntity is repeatable. If you expect to read large amounts of payload data, and you do not use this feature, you should set it to false. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set a log.Logger instance such as: (c) 2012-2014, http://ernestmicklei.com. MIT License
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/robertkrimen/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/robertkrimen/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/robertkrimen/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/robertkrimen/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/robertkrimen/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Package gorilla/mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.domain.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.domain.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well:
Package route is a helper for the core (https://godoc.org/github.com/volatile/core). It provides syntactic sugar that wraps a handler with request method and path filtering. Functions exists for the most common and standard HTTP methods. Example for a GET route: If you need to handle custom methods, Use receives the methods in a strings slice: Remember that HTTP methods are case-sensitive. See RFC 7231 4.1 (https://tools.ietf.org/html/rfc7231#section-4.1). A regular expression is used to match the request path. We think it offers the best balance between performance and power for this kind of job. If you need to use named parameters from the URL, just use a regexp named group and a func(*core.Context, map[string]string) handler type:
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/lufeng4828/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/lufeng4828/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/lufeng4828/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/lufeng4828/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/lufeng4828/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Package restful, a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. The default router is the RouterJSR311 which is an implementation of its spec (http://jsr311.java.net/nonav/releases/1.1/spec/spec.html). However, it uses regular expressions for all its routes which, depending on your usecase, may consume a significant amount of time. The CurlyRouter implementation is more lightweight that also allows you to use wildcards and expressions, but only if needed. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to true, Route functions are responsible for handling any error situation. Default value is false; it will recover from panics. This has performance implications. SetCacheReadEntity controls whether the response data ([]byte) is cached such that ReadEntity is repeatable. If you expect to read large amounts of payload data, and you do not use this feature, you should set it to false. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set a log.Logger instance such as: (c) 2012-2014, http://ernestmicklei.com. MIT License
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/robertkrimen/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/robertkrimen/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/robertkrimen/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/robertkrimen/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/robertkrimen/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Package mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: Groups can be used inside patterns, as long as they are non-capturing (?:re). For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): Note that if any capturing groups are present, mux will panic() during parsing. To prevent this, convert any capturing groups to non-capturing, e.g. change "/{sort:(asc|desc)}" to "/{sort:(?:asc|desc)}". This is a change from prior versions which behaved unpredictably when capturing groups were present. And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Note that the path provided to PathPrefix() represents a "wildcard": calling PathPrefix("/static/").Handler(...) means that the handler will be passed any request that matches "/static/*". This makes it easy to serve static files with mux: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host and query value variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well: Since **vX.Y.Z**, mux supports the addition of middlewares to a Router(https://godoc.org/github.com/gorilla/mux#Router), which are executed if a match is found (including subrouters). Middlewares are defined using the de facto standard type: Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc (closures can access variables from the context where they are created). A very basic middleware which logs the URI of the request being handled could be written as: Middlewares can be added to a router using `Router.Use()`: A more complex authentication middleware, which maps session token to users, could be written as: Note: The handler chain will be stopped if your middleware doesn't call `next.ServeHTTP()` with the corresponding parameters. This can be used to abort a request if the middleware writer wants to.
Package mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: Groups can be used inside patterns, as long as they are non-capturing (?:re). For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): Note that if any capturing groups are present, mux will panic() during parsing. To prevent this, convert any capturing groups to non-capturing, e.g. change "/{sort:(asc|desc)}" to "/{sort:(?:asc|desc)}". This is a change from prior versions which behaved unpredictably when capturing groups were present. And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Note that the path provided to PathPrefix() represents a "wildcard": calling PathPrefix("/static/").Handler(...) means that the handler will be passed any request that matches "/static/*". This makes it easy to serve static files with mux: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host and query value variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well: Mux supports the addition of middlewares to a Router, which are executed in the order they are added if a match is found, including its subrouters. Middlewares are (typically) small pieces of code which take one request, do something with it, and pass it down to another middleware or the final handler. Some common use cases for middleware are request logging, header manipulation, or ResponseWriter hijacking. Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc (closures can access variables from the context where they are created). A very basic middleware which logs the URI of the request being handled could be written as: Middlewares can be added to a router using `Router.Use()`: A more complex authentication middleware, which maps session token to users, could be written as: Note: The handler chain will be stopped if your middleware doesn't call `next.ServeHTTP()` with the corresponding parameters. This can be used to abort a request if the middleware writer wants to.
Package otto is a JavaScript parser and interpreter written natively in Go. Embedding a Go function in JavaScript: You can run (Go) JavaScript from the commandline with: http://github.com/robertkrimen/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/robertkrimen/otto/tree/master/underscore Caveat Emptor Go translates JavaScript-style regular expressions into something that is "regexp" package compatible. Unfortunately, JavaScript has positive lookahead, negative lookahead, and backreferencing, all of which are not supported by Go's RE2-like engine: https://code.google.com/p/re2/wiki/Syntax A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#!topic/golang-nuts/7qgSDWPIh_E More information about RE2: https://code.google.com/p/re2/ JavaScript considers a vertical tab (\000B <VT>) to be part of the whitespace class (\s), while RE2 does not.
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/robertkrimen/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/robertkrimen/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/robertkrimen/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/robertkrimen/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/robertkrimen/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/dorbmon/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/dorbmon/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/dorbmon/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/dorbmon/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/dorbmon/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Vertex is a friendly, fast and flexible RESTful API building framework 1. An API definition framework 2. Request handlers as structs with automatic data mapping 3. Automatic Data Validation 4. An integrated testing framework for your API 5. A middleware framework similar (but not compliant) to negroni 6. Batteries included: JSON rendering, Auto Recover, Static File Serving, Request Logging, and more The basic idea of Vertex revolves around friendly, pre-validated request handlers, that leave the developer with the need to write as little boilerplate code as possible. Routes in the API are mapped to the RequestHandler interface: RequestHandlers have a few interesting characteristics: 1. Fields in structs implementing RequestHandler get automtically filled by request data. 2. Field values are automatically validated and sanitized 3. They do not *(need to)* write to the response writer, they just need to return a response object. You create structs that have all the parameters you need to handle the requests, define validations for these parameters, and Vertex does the rest for you - just return a response object and you're done. Here is an example super simple RequestHandler: As you can see, the "id" parameter that is received as a post/get/path parameter is automatically parsed into the struct when the handler is invoked. If it is missing or invalid, the handler won't even be invoked, but an error will be generated to the client. These are the allowed tags for fields in RequestHandler structs: schema - the parameter name in the request doc - a short documentation string for the field default - the default value for the parameter in case it's missing min - the minimum allowed value for numeric fields (inclusive) max - the maximum allowed value for numeric fields (inclusive) maxlen - the maximal allowed length for strings minlen - the minimal allowed length for strings required true/false - if set to "true", forces the request to have this parameter set allowEmpty true/false - do we allow empty values? pattern - a regular expression that a string must match if this tag is set in query/body/path - optional for non path params. mainly for documentation needs TODO: Support min/max length for string lists Supported types for struct fields are (see : If a field has a custom type that needs automatic deserialization (e.g. a binary Thrift or Protobuf object), we can define a custom Unmarshal method to the type, letting it automatically deserialize parameters. (See the Unmarshaler interface) The unmarshaler should return a new instance of itself with the value set correctly. Example: a type that takes a string and splits in two APIs are defined in a declarative way, preferably separately from defining the the actual handler logic. An API has a few major parts: Here is an example simple API definition: Security Schemes are used to validate requests. The scheme simply receives the request, and returns an error if it is not valid. It can be used to authenticate the user, validate the API key, etc. Vertex comes with some middleware modules included. Currently implemented middleware include: Responses have renderers - that transform the response object to some serialization format. The default is of course JSON, but an HTML renderer using templates also exists. TODO
Package mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well:
Package mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: Groups can be used inside patterns, as long as they are non-capturing (?:re). For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): Note that if any capturing groups are present, mux will panic() during parsing. To prevent this, convert any capturing groups to non-capturing, e.g. change "/{sort:(asc|desc)}" to "/{sort:(?:asc|desc)}". This is a change from prior versions which behaved unpredictably when capturing groups were present. And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Note that the path provided to PathPrefix() represents a "wildcard": calling PathPrefix("/static/").Handler(...) means that the handler will be passed any request that matches "/static/*". This makes it easy to serve static files with mux: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host and query value variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well: Mux supports the addition of middlewares to a Router, which are executed in the order they are added if a match is found, including its subrouters. Middlewares are (typically) small pieces of code which take one request, do something with it, and pass it down to another middleware or the final handler. Some common use cases for middleware are request logging, header manipulation, or ResponseWriter hijacking. Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc (closures can access variables from the context where they are created). A very basic middleware which logs the URI of the request being handled could be written as: Middlewares can be added to a router using `Router.Use()`: A more complex authentication middleware, which maps session token to users, could be written as: Note: The handler chain will be stopped if your middleware doesn't call `next.ServeHTTP()` with the corresponding parameters. This can be used to abort a request if the middleware writer wants to.
Package csgolog provides utilities for parsing a csgo server logfile. It exports types for csgo logfiles, their regular expressions, a function for parsing and a function for converting to non-html-escaped JSON. Look at the examples for Parse and ToJSON for usage instructions. You will find a command-line utility in examples folder as well as an example logfile with ~3000 lines.
Package xurls extracts urls from plain text using regular expressions.
Package mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: Groups can be used inside patterns, as long as they are non-capturing (?:re). For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): Note that if any capturing groups are present, mux will panic() during parsing. To prevent this, convert any capturing groups to non-capturing, e.g. change "/{sort:(asc|desc)}" to "/{sort:(?:asc|desc)}". This is a change from prior versions which behaved unpredictably when capturing groups were present. And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Note that the path provided to PathPrefix() represents a "wildcard": calling PathPrefix("/static/").Handler(...) means that the handler will be passed any request that matches "/static/*". This makes it easy to serve static files with mux: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host and query value variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well: Since **vX.Y.Z**, mux supports the addition of middlewares to a Router(https://godoc.org/github.com/gorilla/mux#Router), which are executed if a match is found (including subrouters). Middlewares are defined using the de facto standard type: Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc (closures can access variables from the context where they are created). A very basic middleware which logs the URI of the request being handled could be written as: Middlewares can be added to a router using `Router.Use()`: A more complex authentication middleware, which maps session token to users, could be written as: Note: The handler chain will be stopped if your middleware doesn't call `next.ServeHTTP()` with the corresponding parameters. This can be used to abort a request if the middleware writer wants to.
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/robertkrimen/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/robertkrimen/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/robertkrimen/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/robertkrimen/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/robertkrimen/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Package bindata converts any file into manageable Go source code. Useful for embedding binary data into a go program. The file data is optionally gzip compressed before being converted to a raw byte slice. The following paragraphs cover some of the customization options which can be specified in the Config struct, which must be passed into the Translate() call. When used with the `Debug` option, the generated code does not actually include the asset data. Instead, it generates function stubs which load the data from the original file on disk. The asset API remains identical between debug and release builds, so your code will not have to change. This is useful during development when you expect the assets to change often. The host application using these assets uses the same API in both cases and will not have to care where the actual data comes from. An example is a Go webserver with some embedded, static web content like HTML, JS and CSS files. While developing it, you do not want to rebuild the whole server and restart it every time you make a change to a bit of javascript. You just want to build and launch the server once. Then just press refresh in the browser to see those changes. Embedding the assets with the `debug` flag allows you to do just that. When you are finished developing and ready for deployment, just re-invoke `go-bindata` without the `-debug` flag. It will now embed the latest version of the assets. The `NoMemCopy` option will alter the way the output file is generated. It will employ a hack that allows us to read the file data directly from the compiled program's `.rodata` section. This ensures that when we call call our generated function, we omit unnecessary memcopies. The downside of this, is that it requires dependencies on the `reflect` and `unsafe` packages. These may be restricted on platforms like AppEngine and thus prevent you from using this mode. Another disadvantage is that the byte slice we create, is strictly read-only. For most use-cases this is not a problem, but if you ever try to alter the returned byte slice, a runtime panic is thrown. Use this mode only on target platforms where memory constraints are an issue. The default behaviour is to use the old code generation method. This prevents the two previously mentioned issues, but will employ at least one extra memcopy and thus increase memory requirements. For instance, consider the following two examples: This would be the default mode, using an extra memcopy but gives a safe implementation without dependencies on `reflect` and `unsafe`: Here is the same functionality, but uses the `.rodata` hack. The byte slice returned from this example can not be written to without generating a runtime error. The NoCompress option indicates that the supplied assets are *not* GZIP compressed before being turned into Go code. The data should still be accessed through a function call, so nothing changes in the API. This feature is useful if you do not care for compression, or the supplied resource is already compressed. Doing it again would not add any value and may even increase the size of the data. The default behaviour of the program is to use compression. The keys used in the `_bindata` map are the same as the input file name passed to `go-bindata`. This includes the path. In most cases, this is not desirable, as it puts potentially sensitive information in your code base. For this purpose, the tool supplies another command line flag `-prefix`. This accepts a [regular expression](https://github.com/google/re2/wiki/Syntax) string, which will be used to match a portion of the map keys and function names that should be stripped out. For example, running without the `-prefix` flag, we get: Running with the `-prefix` flag, we get: With the optional Tags field, you can specify any go build tags that must be fulfilled for the output file to be included in a build. This is useful when including binary data in multiple formats, where the desired format is specified at build time with the appropriate tags. The tags are appended to a `// +build` line in the beginning of the output file and must follow the build tags syntax specified by the go tool. When you want to embed big files or plenty of files, then the generated output is really big (maybe over 3Mo). Even if the generated file shouldn't be read, you probably need use analysis tool or an editor which can become slower with a such file. Generating big files can be avoided with `-split` command line option. In that case, the given output is a directory path, the tool will generate one source file per file to embed, and it will generate a common file nammed `common.go` which contains commons parts like API.
Package chi is a small, idiomatic and composable router for building HTTP services. chi requires Go 1.7 or newer. Example: See github.com/go-chi/chi/_examples/ for more in-depth examples. URL patterns allow for easy matching of path components in HTTP requests. The matching components can then be accessed using chi.URLParam(). All patterns must begin with a slash. A simple named placeholder {name} matches any sequence of characters up to the next / or the end of the URL. Trailing slashes on paths must be handled explicitly. A placeholder with a name followed by a colon allows a regular expression match, for example {number:\\d+}. The regular expression syntax is Go's normal regexp RE2 syntax, except that regular expressions including { or } are not supported, and / will never be matched. An anonymous regexp pattern is allowed, using an empty string before the colon in the placeholder, such as {:\\d+} The special placeholder of asterisk matches the rest of the requested URL. Any trailing characters in the pattern are ignored. This is the only placeholder which will match / characters. Examples:
Package restful, a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. The default router is the RouterJSR311 which is an implementation of its spec (http://jsr311.java.net/nonav/releases/1.1/spec/spec.html). However, it uses regular expressions for all its routes which, depending on your usecase, may consume a significant amount of time. The CurlyRouter implementation is more lightweight that also allows you to use wildcards and expressions, but only if needed. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to true, Route functions are responsible for handling any error situation. Default value is false; it will recover from panics. This has performance implications. SetCacheReadEntity controls whether the response data ([]byte) is cached such that ReadEntity is repeatable. If you expect to read large amounts of payload data, and you do not use this feature, you should set it to false. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set a log.Logger instance such as: (c) 2012-2014, http://ernestmicklei.com. MIT License
Package restful, a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. The default router is the RouterJSR311 which is an implementation of its spec (http://jsr311.java.net/nonav/releases/1.1/spec/spec.html). However, it uses regular expressions for all its routes which, depending on your usecase, may consume a significant amount of time. The CurlyRouter implementation is more lightweight that also allows you to use wildcards and expressions, but only if needed. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to true, Route functions are responsible for handling any error situation. Default value is false; it will recover from panics. This has performance implications. SetCacheReadEntity controls whether the response data ([]byte) is cached such that ReadEntity is repeatable. If you expect to read large amounts of payload data, and you do not use this feature, you should set it to false. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set a log.Logger instance such as: (c) 2012-2014, http://ernestmicklei.com. MIT License
Package chi is a small, idiomatic and composable router for building HTTP services. chi requires Go 1.7 or newer. Example: See github.com/go-chi/chi/_examples/ for more in-depth examples. URL patterns allow for easy matching of path components in HTTP requests. The matching components can then be accessed using chi.URLParam(). All patterns must begin with a slash. A simple named placeholder {name} matches any sequence of characters up to the next / or the end of the URL. Trailing slashes on paths must be handled explicitly. A placeholder with a name followed by a colon allows a regular expression match, for example {number:\\d+}. The regular expression syntax is Go's normal regexp RE2 syntax, except that regular expressions including { or } are not supported, and / will never be matched. An anonymous regexp pattern is allowed, using an empty string before the colon in the placeholder, such as {:\\d+} The special placeholder of asterisk matches the rest of the requested URL. Any trailing characters in the pattern are ignored. This is the only placeholder which will match / characters. Examples:
Package chi is a small, idiomatic and composable router for building HTTP services. chi requires Go 1.7 or newer. Example: See github.com/go-chi/chi/_examples/ for more in-depth examples. URL patterns allow for easy matching of path components in HTTP requests. The matching components can then be accessed using chi.URLParam(). All patterns must begin with a slash. A simple named placeholder {name} matches any sequence of characters up to the next / or the end of the URL. Trailing slashes on paths must be handled explicitly. A placeholder with a name followed by a colon allows a regular expression match, for example {number:\\d+}. The regular expression syntax is Go's normal regexp RE2 syntax, except that regular expressions including { or } are not supported, and / will never be matched. An anonymous regexp pattern is allowed, using an empty string before the colon in the placeholder, such as {:\\d+} The special placeholder of asterisk matches the rest of the requested URL. Any trailing characters in the pattern are ignored. This is the only placeholder which will match / characters. Examples:
Package skipper provides an HTTP routing library with flexible configuration as well as a runtime update of the routing rules. Skipper works as an HTTP reverse proxy that is responsible for mapping incoming requests to multiple HTTP backend services, based on routes that are selected by the request attributes. At the same time, both the requests and the responses can be augmented by a filter chain that is specifically defined for each route. Optionally, it can provide circuit breaker mechanism individually for each backend host. Skipper can load and update the route definitions from multiple data sources without being restarted. It provides a default executable command with a few built-in filters, however, its primary use case is to be extended with custom filters, predicates or data sources. For further information read 'Extending Skipper'. Skipper took the core design and inspiration from Vulcand: https://github.com/mailgun/vulcand. Skipper is 'go get' compatible. If needed, create a 'go workspace' first: Get the Skipper packages: Create a file with a route: Optionally, verify the syntax of the file: Start Skipper and make an HTTP request: The core of Skipper's request processing is implemented by a reverse proxy in the 'proxy' package. The proxy receives the incoming request, forwards it to the routing engine in order to receive the most specific matching route. When a route matches, the request is forwarded to all filters defined by it. The filters can modify the request or execute any kind of program logic. Once the request has been processed by all the filters, it is forwarded to the backend endpoint of the route. The response from the backend goes once again through all the filters in reverse order. Finally, it is mapped as the response of the original incoming request. Besides the default proxying mechanism, it is possible to define routes without a real network backend endpoint. One of these cases is called a 'shunt' backend, in which case one of the filters needs to handle the request providing its own response (e.g. the 'static' filter). Actually, filters themselves can instruct the request flow to shunt by calling the Serve(*http.Response) method of the filter context. Another case of a route without a network backend is the 'loopback'. A loopback route can be used to match a request, modified by filters, against the lookup tree with different conditions and then execute a different route. One example scenario can be to use a single route as an entry point to execute some calculation to get an A/B testing decision and then matching the updated request metadata for the actual destination route. This way the calculation can be executed for only those requests that don't contain information about a previously calculated decision. For further details, see the 'proxy' and 'filters' package documentation. Finding a request's route happens by matching the request attributes to the conditions in the route's definitions. Such definitions may have the following conditions: - method - path (optionally with wildcards) - path regular expressions - host regular expressions - headers - header regular expressions It is also possible to create custom predicates with any other matching criteria. The relation between the conditions in a route definition is 'and', meaning, that a request must fulfill each condition to match a route. For further details, see the 'routing' package documentation. Filters are applied in order of definition to the request and in reverse order to the response. They are used to modify request and response attributes, such as headers, or execute background tasks, like logging. Some filters may handle the requests without proxying them to service backends. Filters, depending on their implementation, may accept/require parameters, that are set specifically to the route. For further details, see the 'filters' package documentation. Each route has one of the following backends: HTTP endpoint, shunt or loopback. Backend endpoints can be any HTTP service. They are specified by their network address, including the protocol scheme, the domain name or the IP address, and optionally the port number: e.g. "https://www.example.org:4242". (The path and query are sent from the original request, or set by filters.) A shunt route means that Skipper handles the request alone and doesn't make requests to a backend service. In this case, it is the responsibility of one of the filters to generate the response. A loopback route executes the routing mechanism on current state of the request from the start, including the route lookup. This way it serves as a form of an internal redirect. Route definitions consist of the following: - request matching conditions (predicates) - filter chain (optional) - backend (either an HTTP endpoint or a shunt) The eskip package implements the in-memory and text representations of route definitions, including a parser. (Note to contributors: in order to stay compatible with 'go get', the generated part of the parser is stored in the repository. When changing the grammar, 'go generate' needs to be executed explicitly to update the parser.) For further details, see the 'eskip' package documentation Skipper has filter implementations of basic auth and OAuth2. It can be integrated with tokeninfo based OAuth2 providers. For details, see: https://godoc.org/github.com/zalando/skipper/filters/auth. Skipper's route definitions of Skipper are loaded from one or more data sources. It can receive incremental updates from those data sources at runtime. It provides three different data clients: - Kubernetes: Skipper can be used as part of a Kubernetes Ingress Controller implementation together with https://github.com/zalando-incubator/kube-ingress-aws-controller . In this scenario, Skipper uses the Kubernetes API's Ingress extensions as a source for routing. For a complete deployment example, see more details in: https://github.com/zalando-incubator/kubernetes-on-aws/ . - Innkeeper: the Innkeeper service implements a storage for large sets of Skipper routes, with an HTTP+JSON API, OAuth2 authentication and role management. See the 'innkeeper' package and https://github.com/zalando/innkeeper. - etcd: Skipper can load routes and receive updates from etcd clusters (https://github.com/coreos/etcd). See the 'etcd' package. - static file: package eskipfile implements a simple data client, which can load route definitions from a static file in eskip format. Currently, it loads the routes on startup. It doesn't support runtime updates. Skipper can use additional data sources, provided by extensions. Sources must implement the DataClient interface in the routing package. Skipper provides circuit breakers, configured either globally, based on backend hosts or based on individual routes. It supports two types of circuit breaker behavior: open on N consecutive failures, or open on N failures out of M requests. For details, see: https://godoc.org/github.com/zalando/skipper/circuit. Skipper can be started with the default executable command 'skipper', or as a library built into an application. The easiest way to start Skipper as a library is to execute the 'Run' function of the current, root package. Each option accepted by the 'Run' function is wired in the default executable as well, as a command line flag. E.g. EtcdUrls becomes -etcd-urls as a comma separated list. For command line help, enter: An additional utility, eskip, can be used to verify, print, update and delete routes from/to files or etcd (Innkeeper on the roadmap). See the cmd/eskip command package, and/or enter in the command line: Skipper doesn't use dynamically loaded plugins, however, it can be used as a library, and it can be extended with custom predicates, filters and/or custom data sources. To create a custom predicate, one needs to implement the PredicateSpec interface in the routing package. Instances of the PredicateSpec are used internally by the routing package to create the actual Predicate objects as referenced in eskip routes, with concrete arguments. Example, randompredicate.go: In the above example, a custom predicate is created, that can be referenced in eskip definitions with the name 'Random': To create a custom filter we need to implement the Spec interface of the filters package. 'Spec' is the specification of a filter, and it is used to create concrete filter instances, while the raw route definitions are processed. Example, hellofilter.go: The above example creates a filter specification, and in the routes where they are included, the filter instances will set the 'X-Hello' header for each and every response. The name of the filter is 'hello', and in a route definition it is referenced as: The easiest way to create a custom Skipper variant is to implement the required filters (as in the example above) by importing the Skipper package, and starting it with the 'Run' command. Example, hello.go: A file containing the routes, routes.eskip: Start the custom router: The 'Run' function in the root Skipper package starts its own listener but it doesn't provide the best composability. The proxy package, however, provides a standard http.Handler, so it is possible to use it in a more complex solution as a building block for routing. Skipper provides detailed logging of failures, and access logs in Apache log format. Skipper also collects detailed performance metrics, and exposes them on a separate listener endpoint for pulling snapshots. For details, see the 'logging' and 'metrics' packages documentation. The router's performance depends on the environment and on the used filters. Under ideal circumstances, and without filters, the biggest time factor is the route lookup. Skipper is able to scale to thousands of routes with logarithmic performance degradation. However, this comes at the cost of increased memory consumption, due to storing the whole lookup tree in a single structure. Benchmarks for the tree lookup can be run by: In case more aggressive scale is needed, it is possible to setup Skipper in a cascade model, with multiple Skipper instances for specific route segments.
Package restful, a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. The default router is the RouterJSR311 which is an implementation of its spec (http://jsr311.java.net/nonav/releases/1.1/spec/spec.html). However, it uses regular expressions for all its routes which, depending on your usecase, may consume a significant amount of time. The CurlyRouter implementation is more lightweight that also allows you to use wildcards and expressions, but only if needed. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to true, Route functions are responsible for handling any error situation. Default value is false; it will recover from panics. This has performance implications. SetCacheReadEntity controls whether the response data ([]byte) is cached such that ReadEntity is repeatable. If you expect to read large amounts of payload data, and you do not use this feature, you should set it to false. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set a log.Logger instance such as: (c) 2012-2014, http://ernestmicklei.com. MIT License
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/robertkrimen/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/robertkrimen/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/robertkrimen/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/robertkrimen/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/robertkrimen/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Package restful , a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to false, the container will recover from panics. Default value is true If content encoding is enabled then the default strategy for getting new gzip/zlib writers and readers is to use a sync.Pool. Because writers are expensive structures, performance is even more improved when using a preloaded cache. You can also inject your own implementation. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set an implementation of restful.StdLogger (e.g. log.Logger) instance such as: The restful.SetLogger() method allows you to override the logger used by the package. By default restful uses the standard library `log` package and logs to stdout. Different logging packages are supported as long as they conform to `StdLogger` interface defined in the `log` sub-package, writing an adapter for your preferred package is simple. (c) 2012-2015, http://ernestmicklei.com. MIT License
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/robertkrimen/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/robertkrimen/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/robertkrimen/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/robertkrimen/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/robertkrimen/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Package mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: Groups can be used inside patterns, as long as they are non-capturing (?:re). For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): Note that if any capturing groups are present, mux will panic() during parsing. To prevent this, convert any capturing groups to non-capturing, e.g. change "/{sort:(asc|desc)}" to "/{sort:(?:asc|desc)}". This is a change from prior versions which behaved unpredictably when capturing groups were present. And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Note that the path provided to PathPrefix() represents a "wildcard": calling PathPrefix("/static/").Handler(...) means that the handler will be passed any request that matches "/static/*". This makes it easy to serve static files with mux: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host and query value variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well: Since **vX.Y.Z**, mux supports the addition of middlewares to a Router(https://godoc.org/github.com/gorilla/mux#Router), which are executed if a match is found (including subrouters). Middlewares are defined using the de facto standard type: Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc (closures can access variables from the context where they are created). A very basic middleware which logs the URI of the request being handled could be written as: Middlewares can be added to a router using `Router.Use()`: A more complex authentication middleware, which maps session token to users, could be written as: Note: The handler chain will be stopped if your middleware doesn't call `next.ServeHTTP()` with the corresponding parameters. This can be used to abort a request if the middleware writer wants to.
Package regexp implements extended regular expression search.
Package chi is a small, idiomatic and composable router for building HTTP services. chi requires Go 1.7 or newer. Example: See github.com/go-chi/chi/_examples/ for more in-depth examples. URL patterns allow for easy matching of path components in HTTP requests. The matching components can then be accessed using chi.URLParam(). All patterns must begin with a slash. A simple named placeholder {name} matches any sequence of characters up to the next / or the end of the URL. Trailing slashes on paths must be handled explicitly. A placeholder with a name followed by a colon allows a regular expression match, for example {number:\\d+}. The regular expression syntax is Go's normal regexp RE2 syntax, except that regular expressions including { or } are not supported, and / will never be matched. An anonymous regexp pattern is allowed, using an empty string before the colon in the placeholder, such as {:\\d+} The special placeholder of asterisk matches the rest of the requested URL. Any trailing characters in the pattern are ignored. This is the only placeholder which will match / characters. Examples:
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/robertkrimen/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/robertkrimen/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/robertkrimen/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/robertkrimen/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/robertkrimen/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Package restful, a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. The default router is the RouterJSR311 which is an implementation of its spec (http://jsr311.java.net/nonav/releases/1.1/spec/spec.html). However, it uses regular expressions for all its routes which, depending on your usecase, may consume a significant amount of time. The CurlyRouter implementation is more lightweight that also allows you to use wildcards and expressions, but only if needed. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to true, Route functions are responsible for handling any error situation. Default value is false; it will recover from panics. This has performance implications. SetCacheReadEntity controls whether the response data ([]byte) is cached such that ReadEntity is repeatable. If you expect to read large amounts of payload data, and you do not use this feature, you should set it to false. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set a log.Logger instance such as: (c) 2012-2014, http://ernestmicklei.com. MIT License
Package mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: Groups can be used inside patterns, as long as they are non-capturing (?:re). For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): Note that if any capturing groups are present, mux will panic() during parsing. To prevent this, convert any capturing groups to non-capturing, e.g. change "/{sort:(asc|desc)}" to "/{sort:(?:asc|desc)}". This is a change from prior versions which behaved unpredictably when capturing groups were present. And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Note that the path provided to PathPrefix() represents a "wildcard": calling PathPrefix("/static/").Handler(...) means that the handler will be passed any request that matches "/static/*". This makes it easy to serve static files with mux: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host and query value variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well: Mux supports the addition of middlewares to a Router, which are executed in the order they are added if a match is found, including its subrouters. Middlewares are (typically) small pieces of code which take one request, do something with it, and pass it down to another middleware or the final handler. Some common use cases for middleware are request logging, header manipulation, or ResponseWriter hijacking. Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc (closures can access variables from the context where they are created). A very basic middleware which logs the URI of the request being handled could be written as: Middlewares can be added to a router using `Router.Use()`: A more complex authentication middleware, which maps session token to users, could be written as: Note: The handler chain will be stopped if your middleware doesn't call `next.ServeHTTP()` with the corresponding parameters. This can be used to abort a request if the middleware writer wants to.
Package mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: Groups can be used inside patterns, as long as they are non-capturing (?:re). For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): Note that if any capturing groups are present, mux will panic() during parsing. To prevent this, convert any capturing groups to non-capturing, e.g. change "/{sort:(asc|desc)}" to "/{sort:(?:asc|desc)}". This is a change from prior versions which behaved unpredictably when capturing groups were present. And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Note that the path provided to PathPrefix() represents a "wildcard": calling PathPrefix("/static/").Handler(...) means that the handler will be passed any request that matches "/static/*". This makes it easy to serve static files with mux: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host and query value variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well: Mux supports the addition of middlewares to a Router, which are executed in the order they are added if a match is found, including its subrouters. Middlewares are (typically) small pieces of code which take one request, do something with it, and pass it down to another middleware or the final handler. Some common use cases for middleware are request logging, header manipulation, or ResponseWriter hijacking. Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed to it, and then calls the handler passed as parameter to the MiddlewareFunc (closures can access variables from the context where they are created). A very basic middleware which logs the URI of the request being handled could be written as: Middlewares can be added to a router using `Router.Use()`: A more complex authentication middleware, which maps session token to users, could be written as: Note: The handler chain will be stopped if your middleware doesn't call `next.ServeHTTP()` with the corresponding parameters. This can be used to abort a request if the middleware writer wants to.
Package restful, a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. The default router is the RouterJSR311 which is an implementation of its spec (http://jsr311.java.net/nonav/releases/1.1/spec/spec.html). However, it uses regular expressions for all its routes which, depending on your usecase, may consume a significant amount of time. The CurlyRouter implementation is more lightweight that also allows you to use wildcards and expressions, but only if needed. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to true, Route functions are responsible for handling any error situation. Default value is false; it will recover from panics. This has performance implications. SetCacheReadEntity controls whether the response data ([]byte) is cached such that ReadEntity is repeatable. If you expect to read large amounts of payload data, and you do not use this feature, you should set it to false. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set a log.Logger instance such as: (c) 2012-2014, http://ernestmicklei.com. MIT License
Package restful, a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. The default router is the RouterJSR311 which is an implementation of its spec (http://jsr311.java.net/nonav/releases/1.1/spec/spec.html). However, it uses regular expressions for all its routes which, depending on your usecase, may consume a significant amount of time. The CurlyRouter implementation is more lightweight that also allows you to use wildcards and expressions, but only if needed. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to true, Route functions are responsible for handling any error situation. Default value is false; it will recover from panics. This has performance implications. SetCacheReadEntity controls whether the response data ([]byte) is cached such that ReadEntity is repeatable. If you expect to read large amounts of payload data, and you do not use this feature, you should set it to false. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set a log.Logger instance such as: (c) 2012-2014, http://ernestmicklei.com. MIT License
Package restful, a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. The default router is the RouterJSR311 which is an implementation of its spec (http://jsr311.java.net/nonav/releases/1.1/spec/spec.html). However, it uses regular expressions for all its routes which, depending on your usecase, may consume a significant amount of time. The CurlyRouter implementation is more lightweight that also allows you to use wildcards and expressions, but only if needed. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to true, Route functions are responsible for handling any error situation. Default value is false; it will recover from panics. This has performance implications. SetCacheReadEntity controls whether the response data ([]byte) is cached such that ReadEntity is repeatable. If you expect to read large amounts of payload data, and you do not use this feature, you should set it to false. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set a log.Logger instance such as: (c) 2012-2014, http://ernestmicklei.com. MIT License
Package mux implements a request router and dispatcher. The name mux stands for "HTTP request multiplexer". Like the standard http.ServeMux, mux.Router matches incoming requests against a list of registered routes and calls a handler for the route that matches the URL or other conditions. The main features are: Let's start registering a couple of URL paths and handlers: Here we register three routes mapping URL paths to handlers. This is equivalent to how http.HandleFunc() works: if an incoming request URL matches one of the paths, the corresponding handler is called passing (http.ResponseWriter, *http.Request) as parameters. Paths can have variables. They are defined using the format {name} or {name:pattern}. If a regular expression pattern is not defined, the matched variable will be anything until the next slash. For example: Groups can be used inside patterns, as long as they are non-capturing (?:re). For example: The names are used to create a map of route variables which can be retrieved calling mux.Vars(): Note that if any capturing groups are present, mux will panic() during parsing. To prevent this, convert any capturing groups to non-capturing, e.g. change "/{sort:(asc|desc)}" to "/{sort:(?:asc|desc)}". This is a change from prior versions which behaved unpredictably when capturing groups were present. And this is all you need to know about the basic usage. More advanced options are explained below. Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables: There are several other matchers that can be added. To match path prefixes: ...or HTTP methods: ...or URL schemes: ...or header values: ...or query values: ...or to use a custom matcher function: ...and finally, it is possible to combine several matchers in a single route: Setting the same matching conditions again and again can be boring, so we have a way to group several routes that share the same requirements. We call it "subrouting". For example, let's say we have several URLs that should only match when the host is "www.example.com". Create a route for that host and get a "subrouter" from it: Then register routes in the subrouter: The three URL paths we registered above will only be tested if the domain is "www.example.com", because the subrouter is tested first. This is not only convenient, but also optimizes request matching. You can create subrouters combining any attribute matchers accepted by a route. Subrouters can be used to create domain or path "namespaces": you define subrouters in a central place and then parts of the app can register its paths relatively to a given subrouter. There's one more thing about subroutes. When a subrouter has a path prefix, the inner routes use it as base for their paths: Note that the path provided to PathPrefix() represents a "wildcard": calling PathPrefix("/static/").Handler(...) means that the handler will be passed any request that matches "/static/*". This makes it easy to serve static files with mux: Now let's see how to build registered URLs. Routes can be named. All routes that define a name can have their URLs built, or "reversed". We define a name calling Name() on a route. For example: To build a URL, get the route and call the URL() method, passing a sequence of key/value pairs for the route variables. For the previous route, we would do: ...and the result will be a url.URL with the following path: This also works for host variables: All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match. Regex support also exists for matching Headers within a route. For example, we could do: ...and the route will match both requests with a Content-Type of `application/json` as well as `application/text` There's also a way to build only the URL host or path for a route: use the methods URLHost() or URLPath() instead. For the previous route, we would do: And if you use subrouters, host and path defined separately can be built as well:
Package otto is a JavaScript parser and interpreter written natively in Go. http://godoc.org/github.com/kirillDanshin/otto Run something in the VM Get a value out of the VM Set a number Set a string Get the value of an expression An error happens Set a Go function Set a Go function that returns something useful Use the functions in JavaScript A separate parser is available in the parser package if you're just interested in building an AST. http://godoc.org/github.com/kirillDanshin/otto/parser Parse and return an AST otto You can run (Go) JavaScript from the commandline with: http://github.com/kirillDanshin/otto/tree/master/otto Run JavaScript by entering some source on stdin or by giving otto a filename: underscore Optionally include the JavaScript utility-belt library, underscore, with this import: For more information: http://github.com/kirillDanshin/otto/tree/master/underscore The following are some limitations with otto: Go translates JavaScript-style regular expressions into something that is "regexp" compatible via `parser.TransformRegExp`. Unfortunately, RegExp requires backtracking for some patterns, and backtracking is not supported by the standard Go engine: https://code.google.com/p/re2/wiki/Syntax Therefore, the following syntax is incompatible: A brief discussion of these limitations: "Regexp (?!re)" https://groups.google.com/forum/?fromgroups=#%21topic/golang-nuts/7qgSDWPIh_E More information about re2: https://code.google.com/p/re2/ In addition to the above, re2 (Go) has a different definition for \s: [\t\n\f\r ]. The JavaScript definition, on the other hand, also includes \v, Unicode "Separator, Space", etc. If you want to stop long running executions (like third-party code), you can use the interrupt channel to do this: Where is setTimeout/setInterval? These timing functions are not actually part of the ECMA-262 specification. Typically, they belong to the `windows` object (in the browser). It would not be difficult to provide something like these via Go, but you probably want to wrap otto in an event loop in that case. For an example of how this could be done in Go with otto, see natto: http://github.com/robertkrimen/natto Here is some more discussion of the issue: * http://book.mixu.net/node/ch2.html * http://en.wikipedia.org/wiki/Reentrancy_%28computing%29 * http://aaroncrane.co.uk/2009/02/perl_safe_signals/
Package chi is a small, idiomatic and composable router for building HTTP services. chi requires Go 1.7 or newer. Example: See github.com/go-chi/chi/_examples/ for more in-depth examples. URL patterns allow for easy matching of path components in HTTP requests. The matching components can then be accessed using chi.URLParam(). All patterns must begin with a slash. A simple named placeholder {name} matches any sequence of characters up to the next / or the end of the URL. Trailing slashes on paths must be handled explicitly. A placeholder with a name followed by a colon allows a regular expression match, for example {number:\\d+}. The regular expression syntax is Go's normal regexp RE2 syntax, except that regular expressions including { or } are not supported, and / will never be matched. An anonymous regexp pattern is allowed, using an empty string before the colon in the placeholder, such as {:\\d+} The special placeholder of asterisk matches the rest of the requested URL. Any trailing characters in the pattern are ignored. This is the only placeholder which will match / characters. Examples:
Package xurls extracts urls from plain text using regular expressions.
Package restful, a lean package for creating REST-style WebServices without magic. A WebService has a collection of Route objects that dispatch incoming Http Requests to a function calls. Typically, a WebService has a root path (e.g. /users) and defines common MIME types for its routes. WebServices must be added to a container (see below) in order to handler Http requests from a server. A Route is defined by a HTTP method, an URL path and (optionally) the MIME types it consumes (Content-Type) and produces (Accept). This package has the logic to find the best matching Route and if found, call its Function. The (*Request, *Response) arguments provide functions for reading information from the request and writing information back to the response. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-user-resource.go with a full implementation. A Route parameter can be specified using the format "uri/{var[:regexp]}" or the special version "uri/{var:*}" for matching the tail of the path. For example, /persons/{name:[A-Z][A-Z]} can be used to restrict values for the parameter "name" to only contain capital alphabetic characters. Regular expressions must use the standard Go syntax as described in the regexp package. (https://code.google.com/p/re2/wiki/Syntax) This feature requires the use of a CurlyRouter. A Container holds a collection of WebServices, Filters and a http.ServeMux for multiplexing http requests. Using the statements "restful.Add(...) and restful.Filter(...)" will register WebServices and Filters to the Default Container. The Default container of go-restful uses the http.DefaultServeMux. You can create your own Container and create a new http.Server for that particular container. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. You can use filters to perform generic logging, measurement, authentication, redirect, set response headers etc. In the restful package there are three hooks into the request,response flow where filters can be added. Each filter must define a FilterFunction: Use the following statement to pass the request,response pair to the next filter or RouteFunction These are processed before any registered WebService. These are processed before any Route of a WebService. These are processed before calling the function associated with the Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-filters.go with full implementations. Two encodings are supported: gzip and deflate. To enable this for all responses: If a Http request includes the Accept-Encoding header then the response content will be compressed using the specified encoding. Alternatively, you can create a Filter that performs the encoding and install it per WebService or Route. See the example https://github.com/emicklei/go-restful/blob/master/examples/restful-encoding-filter.go By installing a pre-defined container filter, your Webservice(s) can respond to the OPTIONS Http request. By installing the filter of a CrossOriginResourceSharing (CORS), your WebService(s) can handle CORS requests. Unexpected things happen. If a request cannot be processed because of a failure, your service needs to tell via the response what happened and why. For this reason HTTP status codes exist and it is important to use the correct code in every exceptional situation. If path or query parameters are not valid (content or type) then use http.StatusBadRequest. Despite a valid URI, the resource requested may not be available If the application logic could not process the request (or write the response) then use http.StatusInternalServerError. The request has a valid URL but the method (GET,PUT,POST,...) is not allowed. The request does not have or has an unknown Accept Header set for this operation. The request does not have or has an unknown Content-Type Header set for this operation. In addition to setting the correct (error) Http status code, you can choose to write a ServiceError message on the response. This package has several options that affect the performance of your service. It is important to understand them and how you can change it. The default router is the RouterJSR311 which is an implementation of its spec (http://jsr311.java.net/nonav/releases/1.1/spec/spec.html). However, it uses regular expressions for all its routes which, depending on your usecase, may consume a significant amount of time. The CurlyRouter implementation is more lightweight that also allows you to use wildcards and expressions, but only if needed. DoNotRecover controls whether panics will be caught to return HTTP 500. If set to true, Route functions are responsible for handling any error situation. Default value is false; it will recover from panics. This has performance implications. SetCacheReadEntity controls whether the response data ([]byte) is cached such that ReadEntity is repeatable. If you expect to read large amounts of payload data, and you do not use this feature, you should set it to false. This package has the means to produce detail logging of the complete Http request matching process and filter invocation. Enabling this feature requires you to set a log.Logger instance such as: (c) 2012-2014, http://ernestmicklei.com. MIT License