memberlist is a library that manages cluster membership and member failure detection using a gossip based protocol. The use cases for such a library are far-reaching: all distributed systems require membership, and memberlist is a re-usable solution to managing cluster membership and node failure detection. memberlist is eventually consistent but converges quickly on average. The speed at which it converges can be heavily tuned via various knobs on the protocol. Node failures are detected and network partitions are partially tolerated by attempting to communicate to potentially dead nodes through multiple routes.
Package plist implements encoding and decoding of Apple's "property list" format. Property lists come in three sorts: plain text (GNUStep and OpenStep), XML and binary. plist supports all of them. The mapping between property list and Go objects is described in the documentation for the Marshal and Unmarshal functions.
Package skiplist implement skip list data structure. See wikipedia for more details about this data structure. http://en.wikipedia.org/wiki/Skip_list Skip list is basically an ordered map. Here is a sample to use this package.
Package plist implements encoding and decoding of Apple's "property list" format. Property lists come in three sorts: plain text (GNUStep and OpenStep), XML and binary. plist supports all of them. The mapping between property list and Go objects is described in the documentation for the Marshal and Unmarshal functions.
Package tcplisten provides customizable TCP net.Listener with various performance-related options: SO_REUSEPORT. This option allows linear scaling server performance on multi-CPU servers. See https://www.nginx.com/blog/socket-sharding-nginx-release-1-9-1/ for details. TCP_DEFER_ACCEPT. This option expects the server reads from the accepted connection before writing to them. TCP_FASTOPEN. See https://lwn.net/Articles/508865/ for details. The package is derived from https://github.com/kavu/go_reuseport .
Package skiplist is an implementation of a skiplist to store elements in increasing order. It allows finding, insertion and deletion operations in approximately O(n log(n)). Additionally, there are methods for retrieving the next and previous element as well as changing the actual value without the need for re-insertion (as long as the key stays the same!) Skiplist is a fast alternative to a balanced tree.
Package pgpwordlist provides the pgpwordlist for easier hashes/seeds. This package provides the pgpwordlist for use when generating a human readable hash or seed as well as functions for working with it.
Package naughtystrings is a collection of strings that have a high probability of causing issues when used as user input.
Package tcplisten provides customizable TCP net.Listener with various performance-related options: SO_REUSEPORT. This option allows linear scaling server performance on multi-CPU servers. See https://www.nginx.com/blog/socket-sharding-nginx-release-1-9-1/ for details. TCP_DEFER_ACCEPT. This option expects the server reads from the accepted connection before writing to them. TCP_FASTOPEN. See https://lwn.net/Articles/508865/ for details. The package is derived from https://github.com/kavu/go_reuseport .
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 sdk is the official AWS SDK for the Go programming language. The AWS SDK for Go provides APIs and utilities that developers can use to build Go applications that use AWS services, such as Amazon Elastic Compute Cloud (Amazon EC2) and Amazon Simple Storage Service (Amazon S3). The SDK removes the complexity of coding directly against a web service interface. It hides a lot of the lower-level plumbing, such as authentication, request retries, and error handling. The SDK also includes helpful utilities on top of the AWS APIs that add additional capabilities and functionality. For example, the Amazon S3 Download and Upload Manager will automatically split up large objects into multiple parts and transfer them concurrently. See the s3manager package documentation for more information. https://docs.aws.amazon.com/sdk-for-go/api/service/s3/s3manager/ Checkout the Getting Started Guide and API Reference Docs detailed the SDK's components and details on each AWS client the SDK supports. The Getting Started Guide provides examples and detailed description of how to get setup with the SDK. https://docs.aws.amazon.com/sdk-for-go/v1/developer-guide/welcome.html The API Reference Docs include a detailed breakdown of the SDK's components such as utilities and AWS clients. Use this as a reference of the Go types included with the SDK, such as AWS clients, API operations, and API parameters. https://docs.aws.amazon.com/sdk-for-go/api/ The SDK is composed of two main components, SDK core, and service clients. The SDK core packages are all available under the aws package at the root of the SDK. Each client for a supported AWS service is available within its own package under the service folder at the root of the SDK. aws - SDK core, provides common shared types such as Config, Logger, and utilities to make working with API parameters easier. awserr - Provides the error interface that the SDK will use for all errors that occur in the SDK's processing. This includes service API response errors as well. The Error type is made up of a code and message. Cast the SDK's returned error type to awserr.Error and call the Code method to compare returned error to specific error codes. See the package's documentation for additional values that can be extracted such as RequestId. credentials - Provides the types and built in credentials providers the SDK will use to retrieve AWS credentials to make API requests with. Nested under this folder are also additional credentials providers such as stscreds for assuming IAM roles, and ec2rolecreds for EC2 Instance roles. endpoints - Provides the AWS Regions and Endpoints metadata for the SDK. Use this to lookup AWS service endpoint information such as which services are in a region, and what regions a service is in. Constants are also provided for all region identifiers, e.g UsWest2RegionID for "us-west-2". session - Provides initial default configuration, and load configuration from external sources such as environment and shared credentials file. request - Provides the API request sending, and retry logic for the SDK. This package also includes utilities for defining your own request retryer, and configuring how the SDK processes the request. service - Clients for AWS services. All services supported by the SDK are available under this folder. The SDK includes the Go types and utilities you can use to make requests to AWS service APIs. Within the service folder at the root of the SDK you'll find a package for each AWS service the SDK supports. All service clients follows a common pattern of creation and usage. When creating a client for an AWS service you'll first need to have a Session value constructed. The Session provides shared configuration that can be shared between your service clients. When service clients are created you can pass in additional configuration via the aws.Config type to override configuration provided by in the Session to create service client instances with custom configuration. Once the service's client is created you can use it to make API requests the AWS service. These clients are safe to use concurrently. In the AWS SDK for Go, you can configure settings for service clients, such as the log level and maximum number of retries. Most settings are optional; however, for each service client, you must specify a region and your credentials. The SDK uses these values to send requests to the correct AWS region and sign requests with the correct credentials. You can specify these values as part of a session or as environment variables. See the SDK's configuration guide for more information. https://docs.aws.amazon.com/sdk-for-go/v1/developer-guide/configuring-sdk.html See the session package documentation for more information on how to use Session with the SDK. https://docs.aws.amazon.com/sdk-for-go/api/aws/session/ See the Config type in the aws package for more information on configuration options. https://docs.aws.amazon.com/sdk-for-go/api/aws/#Config When using the SDK you'll generally need your AWS credentials to authenticate with AWS services. The SDK supports multiple methods of supporting these credentials. By default the SDK will source credentials automatically from its default credential chain. See the session package for more information on this chain, and how to configure it. The common items in the credential chain are the following: Environment Credentials - Set of environment variables that are useful when sub processes are created for specific roles. Shared Credentials file (~/.aws/credentials) - This file stores your credentials based on a profile name and is useful for local development. EC2 Instance Role Credentials - Use EC2 Instance Role to assign credentials to application running on an EC2 instance. This removes the need to manage credential files in production. Credentials can be configured in code as well by setting the Config's Credentials value to a custom provider or using one of the providers included with the SDK to bypass the default credential chain and use a custom one. This is helpful when you want to instruct the SDK to only use a specific set of credentials or providers. This example creates a credential provider for assuming an IAM role, "myRoleARN" and configures the S3 service client to use that role for API requests. See the credentials package documentation for more information on credential providers included with the SDK, and how to customize the SDK's usage of credentials. https://docs.aws.amazon.com/sdk-for-go/api/aws/credentials The SDK has support for the shared configuration file (~/.aws/config). This support can be enabled by setting the environment variable, "AWS_SDK_LOAD_CONFIG=1", or enabling the feature in code when creating a Session via the Option's SharedConfigState parameter. In addition to the credentials you'll need to specify the region the SDK will use to make AWS API requests to. In the SDK you can specify the region either with an environment variable, or directly in code when a Session or service client is created. The last value specified in code wins if the region is specified multiple ways. To set the region via the environment variable set the "AWS_REGION" to the region you want to the SDK to use. Using this method to set the region will allow you to run your application in multiple regions without needing additional code in the application to select the region. The endpoints package includes constants for all regions the SDK knows. The values are all suffixed with RegionID. These values are helpful, because they reduce the need to type the region string manually. To set the region on a Session use the aws package's Config struct parameter Region to the AWS region you want the service clients created from the session to use. This is helpful when you want to create multiple service clients, and all of the clients make API requests to the same region. See the endpoints package for the AWS Regions and Endpoints metadata. https://docs.aws.amazon.com/sdk-for-go/api/aws/endpoints/ In addition to setting the region when creating a Session you can also set the region on a per service client bases. This overrides the region of a Session. This is helpful when you want to create service clients in specific regions different from the Session's region. See the Config type in the aws package for more information and additional options such as setting the Endpoint, and other service client configuration options. https://docs.aws.amazon.com/sdk-for-go/api/aws/#Config Once the client is created you can make an API request to the service. Each API method takes a input parameter, and returns the service response and an error. The SDK provides methods for making the API call in multiple ways. In this list we'll use the S3 ListObjects API as an example for the different ways of making API requests. ListObjects - Base API operation that will make the API request to the service. ListObjectsRequest - API methods suffixed with Request will construct the API request, but not send it. This is also helpful when you want to get a presigned URL for a request, and share the presigned URL instead of your application making the request directly. ListObjectsPages - Same as the base API operation, but uses a callback to automatically handle pagination of the API's response. ListObjectsWithContext - Same as base API operation, but adds support for the Context pattern. This is helpful for controlling the canceling of in flight requests. See the Go standard library context package for more information. This method also takes request package's Option functional options as the variadic argument for modifying how the request will be made, or extracting information from the raw HTTP response. ListObjectsPagesWithContext - same as ListObjectsPages, but adds support for the Context pattern. Similar to ListObjectsWithContext this method also takes the request package's Option function option types as the variadic argument. In addition to the API operations the SDK also includes several higher level methods that abstract checking for and waiting for an AWS resource to be in a desired state. In this list we'll use WaitUntilBucketExists to demonstrate the different forms of waiters. WaitUntilBucketExists. - Method to make API request to query an AWS service for a resource's state. Will return successfully when that state is accomplished. WaitUntilBucketExistsWithContext - Same as WaitUntilBucketExists, but adds support for the Context pattern. In addition these methods take request package's WaiterOptions to configure the waiter, and how underlying request will be made by the SDK. The API method will document which error codes the service might return for the operation. These errors will also be available as const strings prefixed with "ErrCode" in the service client's package. If there are no errors listed in the API's SDK documentation you'll need to consult the AWS service's API documentation for the errors that could be returned. Pagination helper methods are suffixed with "Pages", and provide the functionality needed to round trip API page requests. Pagination methods take a callback function that will be called for each page of the API's response. Waiter helper methods provide the functionality to wait for an AWS resource state. These methods abstract the logic needed to to check the state of an AWS resource, and wait until that resource is in a desired state. The waiter will block until the resource is in the state that is desired, an error occurs, or the waiter times out. If a resource times out the error code returned will be request.WaiterResourceNotReadyErrorCode. This example shows a complete working Go file which will upload a file to S3 and use the Context pattern to implement timeout logic that will cancel the request if it takes too long. This example highlights how to use sessions, create a service client, make a request, handle the error, and process the response.
Package validator implements value validations for structs and individual fields based on tags. It can also handle Cross-Field and Cross-Struct validation for nested structs and has the ability to dive into arrays and maps of any type. see more examples https://github.com/go-playground/validator/tree/master/_examples Validator is designed to be thread-safe and used as a singleton instance. It caches information about your struct and validations, in essence only parsing your validation tags once per struct type. Using multiple instances neglects the benefit of caching. The not thread-safe functions are explicitly marked as such in the documentation. Doing things this way is actually the way the standard library does, see the file.Open method here: The authors return type "error" to avoid the issue discussed in the following, where err is always != nil: Validator only InvalidValidationError for bad validation input, nil or ValidationErrors as type error; so, in your code all you need to do is check if the error returned is not nil, and if it's not check if error is InvalidValidationError ( if necessary, most of the time it isn't ) type cast it to type ValidationErrors like so err.(validator.ValidationErrors). Custom Validation functions can be added. Example: Cross-Field Validation can be done via the following tags: If, however, some custom cross-field validation is required, it can be done using a custom validation. Why not just have cross-fields validation tags (i.e. only eqcsfield and not eqfield)? The reason is efficiency. If you want to check a field within the same struct "eqfield" only has to find the field on the same struct (1 level). But, if we used "eqcsfield" it could be multiple levels down. Example: Multiple validators on a field will process in the order defined. Example: Bad Validator definitions are not handled by the library. Example: Baked In Cross-Field validation only compares fields on the same struct. If Cross-Field + Cross-Struct validation is needed you should implement your own custom validator. Comma (",") is the default separator of validation tags. If you wish to have a comma included within the parameter (i.e. excludesall=,) you will need to use the UTF-8 hex representation 0x2C, which is replaced in the code as a comma, so the above will become excludesall=0x2C. Pipe ("|") is the 'or' validation tags deparator. If you wish to have a pipe included within the parameter i.e. excludesall=| you will need to use the UTF-8 hex representation 0x7C, which is replaced in the code as a pipe, so the above will become excludesall=0x7C Here is a list of the current built in validators: Tells the validation to skip this struct field; this is particularly handy in ignoring embedded structs from being validated. (Usage: -) This is the 'or' operator allowing multiple validators to be used and accepted. (Usage: rgb|rgba) <-- this would allow either rgb or rgba colors to be accepted. This can also be combined with 'and' for example ( Usage: omitempty,rgb|rgba) When a field that is a nested struct is encountered, and contains this flag any validation on the nested struct will be run, but none of the nested struct fields will be validated. This is useful if inside of your program you know the struct will be valid, but need to verify it has been assigned. NOTE: only "required" and "omitempty" can be used on a struct itself. Same as structonly tag except that any struct level validations will not run. Allows conditional validation, for example if a field is not set with a value (Determined by the "required" validator) then other validation such as min or max won't run, but if a value is set validation will run. Allows to skip the validation if the value is nil (same as omitempty, but only for the nil-values). This tells the validator to dive into a slice, array or map and validate that level of the slice, array or map with the validation tags that follow. Multidimensional nesting is also supported, each level you wish to dive will require another dive tag. dive has some sub-tags, 'keys' & 'endkeys', please see the Keys & EndKeys section just below. Example #1 Example #2 Keys & EndKeys These are to be used together directly after the dive tag and tells the validator that anything between 'keys' and 'endkeys' applies to the keys of a map and not the values; think of it like the 'dive' tag, but for map keys instead of values. Multidimensional nesting is also supported, each level you wish to validate will require another 'keys' and 'endkeys' tag. These tags are only valid for maps. Example #1 Example #2 This validates that the value is not the data types default zero value. For numbers ensures value is not zero. For strings ensures value is not "". For booleans ensures value is not false. For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. For structs ensures value is not the zero value when using WithRequiredStructEnabled. The field under validation must be present and not empty only if all the other specified fields are equal to the value following the specified field. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. For structs ensures value is not the zero value. Examples: The field under validation must be present and not empty unless all the other specified fields are equal to the value following the specified field. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. For structs ensures value is not the zero value. Examples: The field under validation must be present and not empty only if any of the other specified fields are present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. For structs ensures value is not the zero value. Examples: The field under validation must be present and not empty only if all of the other specified fields are present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. For structs ensures value is not the zero value. Example: The field under validation must be present and not empty only when any of the other specified fields are not present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. For structs ensures value is not the zero value. Examples: The field under validation must be present and not empty only when all of the other specified fields are not present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. For structs ensures value is not the zero value. Example: The field under validation must not be present or not empty only if all the other specified fields are equal to the value following the specified field. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. For structs ensures value is not the zero value. Examples: The field under validation must not be present or empty unless all the other specified fields are equal to the value following the specified field. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. For structs ensures value is not the zero value. Examples: This validates that the value is the default value and is almost the opposite of required. For numbers, length will ensure that the value is equal to the parameter given. For strings, it checks that the string length is exactly that number of characters. For slices, arrays, and maps, validates the number of items. Example #1 Example #2 (time.Duration) For time.Duration, len will ensure that the value is equal to the duration given in the parameter. For numbers, max will ensure that the value is less than or equal to the parameter given. For strings, it checks that the string length is at most that number of characters. For slices, arrays, and maps, validates the number of items. Example #1 Example #2 (time.Duration) For time.Duration, max will ensure that the value is less than or equal to the duration given in the parameter. For numbers, min will ensure that the value is greater or equal to the parameter given. For strings, it checks that the string length is at least that number of characters. For slices, arrays, and maps, validates the number of items. Example #1 Example #2 (time.Duration) For time.Duration, min will ensure that the value is greater than or equal to the duration given in the parameter. For strings & numbers, eq will ensure that the value is equal to the parameter given. For slices, arrays, and maps, validates the number of items. Example #1 Example #2 (time.Duration) For time.Duration, eq will ensure that the value is equal to the duration given in the parameter. For strings & numbers, ne will ensure that the value is not equal to the parameter given. For slices, arrays, and maps, validates the number of items. Example #1 Example #2 (time.Duration) For time.Duration, ne will ensure that the value is not equal to the duration given in the parameter. For strings, ints, and uints, oneof will ensure that the value is one of the values in the parameter. The parameter should be a list of values separated by whitespace. Values may be strings or numbers. To match strings with spaces in them, include the target string between single quotes. For numbers, this will ensure that the value is greater than the parameter given. For strings, it checks that the string length is greater than that number of characters. For slices, arrays and maps it validates the number of items. Example #1 Example #2 (time.Time) For time.Time ensures the time value is greater than time.Now.UTC(). Example #3 (time.Duration) For time.Duration, gt will ensure that the value is greater than the duration given in the parameter. Same as 'min' above. Kept both to make terminology with 'len' easier. Example #1 Example #2 (time.Time) For time.Time ensures the time value is greater than or equal to time.Now.UTC(). Example #3 (time.Duration) For time.Duration, gte will ensure that the value is greater than or equal to the duration given in the parameter. For numbers, this will ensure that the value is less than the parameter given. For strings, it checks that the string length is less than that number of characters. For slices, arrays, and maps it validates the number of items. Example #1 Example #2 (time.Time) For time.Time ensures the time value is less than time.Now.UTC(). Example #3 (time.Duration) For time.Duration, lt will ensure that the value is less than the duration given in the parameter. Same as 'max' above. Kept both to make terminology with 'len' easier. Example #1 Example #2 (time.Time) For time.Time ensures the time value is less than or equal to time.Now.UTC(). Example #3 (time.Duration) For time.Duration, lte will ensure that the value is less than or equal to the duration given in the parameter. This will validate the field value against another fields value either within a struct or passed in field. Example #1: Example #2: Field Equals Another Field (relative) This does the same as eqfield except that it validates the field provided relative to the top level struct. This will validate the field value against another fields value either within a struct or passed in field. Examples: Field Does Not Equal Another Field (relative) This does the same as nefield except that it validates the field provided relative to the top level struct. Only valid for Numbers, time.Duration and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as gtfield except that it validates the field provided relative to the top level struct. Only valid for Numbers, time.Duration and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as gtefield except that it validates the field provided relative to the top level struct. Only valid for Numbers, time.Duration and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as ltfield except that it validates the field provided relative to the top level struct. Only valid for Numbers, time.Duration and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as ltefield except that it validates the field provided relative to the top level struct. This does the same as contains except for struct fields. It should only be used with string types. See the behavior of reflect.Value.String() for behavior on other types. This does the same as excludes except for struct fields. It should only be used with string types. See the behavior of reflect.Value.String() for behavior on other types. For arrays & slices, unique will ensure that there are no duplicates. For maps, unique will ensure that there are no duplicate values. For slices of struct, unique will ensure that there are no duplicate values in a field of the struct specified via a parameter. This validates that a string value contains ASCII alpha characters only This validates that a string value contains ASCII alphanumeric characters only This validates that a string value contains unicode alpha characters only This validates that a string value contains unicode alphanumeric characters only This validates that a string value can successfully be parsed into a boolean with strconv.ParseBool This validates that a string value contains number values only. For integers or float it returns true. This validates that a string value contains a basic numeric value. basic excludes exponents etc... for integers or float it returns true. This validates that a string value contains a valid hexadecimal. This validates that a string value contains a valid hex color including hashtag (#) This validates that a string value contains only lowercase characters. An empty string is not a valid lowercase string. This validates that a string value contains only uppercase characters. An empty string is not a valid uppercase string. This validates that a string value contains a valid rgb color This validates that a string value contains a valid rgba color This validates that a string value contains a valid hsl color This validates that a string value contains a valid hsla color This validates that a string value contains a valid E.164 Phone number https://en.wikipedia.org/wiki/E.164 (ex. +1123456789) This validates that a string value contains a valid email This may not conform to all possibilities of any rfc standard, but neither does any email provider accept all possibilities. This validates that a string value is valid JSON This validates that a string value is a valid JWT This validates that a string value contains a valid file path and that the file exists on the machine. This is done using os.Stat, which is a platform independent function. This validates that a string value contains a valid file path and that the file exists on the machine and is an image. This is done using os.Stat and github.com/gabriel-vasile/mimetype This validates that a string value contains a valid file path but does not validate the existence of that file. This is done using os.Stat, which is a platform independent function. This validates that a string value contains a valid url This will accept any url the golang request uri accepts but must contain a schema for example http:// or rtmp:// This validates that a string value contains a valid uri This will accept any uri the golang request uri accepts This validates that a string value contains a valid URN according to the RFC 2141 spec. This validates that a string value contains a valid bas324 value. Although an empty string is valid base32 this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag. This validates that a string value contains a valid base64 value. Although an empty string is valid base64 this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag. This validates that a string value contains a valid base64 URL safe value according the RFC4648 spec. Although an empty string is a valid base64 URL safe value, this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag. This validates that a string value contains a valid base64 URL safe value, but without = padding, according the RFC4648 spec, section 3.2. Although an empty string is a valid base64 URL safe value, this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag. This validates that a string value contains a valid bitcoin address. The format of the string is checked to ensure it matches one of the three formats P2PKH, P2SH and performs checksum validation. Bitcoin Bech32 Address (segwit) This validates that a string value contains a valid bitcoin Bech32 address as defined by bip-0173 (https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki) Special thanks to Pieter Wuille for providing reference implementations. This validates that a string value contains a valid ethereum address. The format of the string is checked to ensure it matches the standard Ethereum address format. This validates that a string value contains the substring value. This validates that a string value contains any Unicode code points in the substring value. This validates that a string value contains the supplied rune value. This validates that a string value does not contain the substring value. This validates that a string value does not contain any Unicode code points in the substring value. This validates that a string value does not contain the supplied rune value. This validates that a string value starts with the supplied string value This validates that a string value ends with the supplied string value This validates that a string value does not start with the supplied string value This validates that a string value does not end with the supplied string value This validates that a string value contains a valid isbn10 or isbn13 value. This validates that a string value contains a valid isbn10 value. This validates that a string value contains a valid isbn13 value. This validates that a string value contains a valid UUID. Uppercase UUID values will not pass - use `uuid_rfc4122` instead. This validates that a string value contains a valid version 3 UUID. Uppercase UUID values will not pass - use `uuid3_rfc4122` instead. This validates that a string value contains a valid version 4 UUID. Uppercase UUID values will not pass - use `uuid4_rfc4122` instead. This validates that a string value contains a valid version 5 UUID. Uppercase UUID values will not pass - use `uuid5_rfc4122` instead. This validates that a string value contains a valid ULID value. This validates that a string value contains only ASCII characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains only printable ASCII characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains one or more multibyte characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains a valid DataURI. NOTE: this will also validate that the data portion is valid base64 This validates that a string value contains a valid latitude. This validates that a string value contains a valid longitude. This validates that a string value contains a valid U.S. Social Security Number. This validates that a string value contains a valid IP Address. This validates that a string value contains a valid v4 IP Address. This validates that a string value contains a valid v6 IP Address. This validates that a string value contains a valid CIDR Address. This validates that a string value contains a valid v4 CIDR Address. This validates that a string value contains a valid v6 CIDR Address. This validates that a string value contains a valid resolvable TCP Address. This validates that a string value contains a valid resolvable v4 TCP Address. This validates that a string value contains a valid resolvable v6 TCP Address. This validates that a string value contains a valid resolvable UDP Address. This validates that a string value contains a valid resolvable v4 UDP Address. This validates that a string value contains a valid resolvable v6 UDP Address. This validates that a string value contains a valid resolvable IP Address. This validates that a string value contains a valid resolvable v4 IP Address. This validates that a string value contains a valid resolvable v6 IP Address. This validates that a string value contains a valid Unix Address. This validates that a string value contains a valid MAC Address. Note: See Go's ParseMAC for accepted formats and types: This validates that a string value is a valid Hostname according to RFC 952 https://tools.ietf.org/html/rfc952 This validates that a string value is a valid Hostname according to RFC 1123 https://tools.ietf.org/html/rfc1123 Full Qualified Domain Name (FQDN) This validates that a string value contains a valid FQDN. This validates that a string value appears to be an HTML element tag including those described at https://developer.mozilla.org/en-US/docs/Web/HTML/Element This validates that a string value is a proper character reference in decimal or hexadecimal format This validates that a string value is percent-encoded (URL encoded) according to https://tools.ietf.org/html/rfc3986#section-2.1 This validates that a string value contains a valid directory and that it exists on the machine. This is done using os.Stat, which is a platform independent function. This validates that a string value contains a valid directory but does not validate the existence of that directory. This is done using os.Stat, which is a platform independent function. It is safest to suffix the string with os.PathSeparator if the directory may not exist at the time of validation. This validates that a string value contains a valid DNS hostname and port that can be used to validate fields typically passed to sockets and connections. This validates that a string value is a valid datetime based on the supplied datetime format. Supplied format must match the official Go time format layout as documented in https://golang.org/pkg/time/ This validates that a string value is a valid country code based on iso3166-1 alpha-2 standard. see: https://www.iso.org/iso-3166-country-codes.html This validates that a string value is a valid country code based on iso3166-1 alpha-3 standard. see: https://www.iso.org/iso-3166-country-codes.html This validates that a string value is a valid country code based on iso3166-1 alpha-numeric standard. see: https://www.iso.org/iso-3166-country-codes.html This validates that a string value is a valid BCP 47 language tag, as parsed by language.Parse. More information on https://pkg.go.dev/golang.org/x/text/language BIC (SWIFT code) This validates that a string value is a valid Business Identifier Code (SWIFT code), defined in ISO 9362. More information on https://www.iso.org/standard/60390.html This validates that a string value is a valid dns RFC 1035 label, defined in RFC 1035. More information on https://datatracker.ietf.org/doc/html/rfc1035 This validates that a string value is a valid time zone based on the time zone database present on the system. Although empty value and Local value are allowed by time.LoadLocation golang function, they are not allowed by this validator. More information on https://golang.org/pkg/time/#LoadLocation This validates that a string value is a valid semver version, defined in Semantic Versioning 2.0.0. More information on https://semver.org/ This validates that a string value is a valid cve id, defined in cve mitre. More information on https://cve.mitre.org/ This validates that a string value contains a valid credit card number using Luhn algorithm. This validates that a string or (u)int value contains a valid checksum using the Luhn algorithm. This validates that a string is a valid 24 character hexadecimal string or valid connection string. Example: This validates that a string value contains a valid cron expression. This validates that a string is valid for use with SpiceDb for the indicated purpose. If no purpose is given, a purpose of 'id' is assumed. Alias Validators and Tags NOTE: When returning an error, the tag returned in "FieldError" will be the alias tag unless the dive tag is part of the alias. Everything after the dive tag is not reported as the alias tag. Also, the "ActualTag" in the before case will be the actual tag within the alias that failed. Here is a list of the current built in alias tags: Validator notes: A collection of validation rules that are frequently needed but are more complex than the ones found in the baked in validators. A non standard validator must be registered manually like you would with your own custom validation functions. Example of registration and use: Here is a list of the current non standard validators: This package panics when bad input is provided, this is by design, bad code like that should not make it to production.
Package cron implements a cron spec parser and job runner. To download the specific tagged release, run: Import it in your program as: It requires Go 1.11 or later due to usage of Go Modules. Callers may register Funcs to be invoked on a given schedule. Cron will run them in their own goroutines. A cron expression represents a set of times, using 5 space-separated fields. Month and Day-of-week field values are case insensitive. "SUN", "Sun", and "sun" are equally accepted. The specific interpretation of the format is based on the Cron Wikipedia page: https://en.wikipedia.org/wiki/Cron Alternative Cron expression formats support other fields like seconds. You can implement that by creating a custom Parser as follows. Since adding Seconds is the most common modification to the standard cron spec, cron provides a builtin function to do that, which is equivalent to the custom parser you saw earlier, except that its seconds field is REQUIRED: That emulates Quartz, the most popular alternative Cron schedule format: http://www.quartz-scheduler.org/documentation/quartz-2.x/tutorials/crontrigger.html Asterisk ( * ) The asterisk indicates that the cron expression will match for all values of the field; e.g., using an asterisk in the 5th field (month) would indicate every month. Slash ( / ) Slashes are used to describe increments of ranges. For example 3-59/15 in the 1st field (minutes) would indicate the 3rd minute of the hour and every 15 minutes thereafter. The form "*\/..." is equivalent to the form "first-last/...", that is, an increment over the largest possible range of the field. The form "N/..." is accepted as meaning "N-MAX/...", that is, starting at N, use the increment until the end of that specific range. It does not wrap around. Comma ( , ) Commas are used to separate items of a list. For example, using "MON,WED,FRI" in the 5th field (day of week) would mean Mondays, Wednesdays and Fridays. Hyphen ( - ) Hyphens are used to define ranges. For example, 9-17 would indicate every hour between 9am and 5pm inclusive. Question mark ( ? ) Question mark may be used instead of '*' for leaving either day-of-month or day-of-week blank. You may use one of several pre-defined schedules in place of a cron expression. You may also schedule a job to execute at fixed intervals, starting at the time it's added or cron is run. This is supported by formatting the cron spec like this: where "duration" is a string accepted by time.ParseDuration (http://golang.org/pkg/time/#ParseDuration). For example, "@every 1h30m10s" would indicate a schedule that activates after 1 hour, 30 minutes, 10 seconds, and then every interval after that. Note: The interval does not take the job runtime into account. For example, if a job takes 3 minutes to run, and it is scheduled to run every 5 minutes, it will have only 2 minutes of idle time between each run. By default, all interpretation and scheduling is done in the machine's local time zone (time.Local). You can specify a different time zone on construction: Individual cron schedules may also override the time zone they are to be interpreted in by providing an additional space-separated field at the beginning of the cron spec, of the form "CRON_TZ=Asia/Tokyo". For example: The prefix "TZ=(TIME ZONE)" is also supported for legacy compatibility. Be aware that jobs scheduled during daylight-savings leap-ahead transitions will not be run! A Cron runner may be configured with a chain of job wrappers to add cross-cutting functionality to all submitted jobs. For example, they may be used to achieve the following effects: Install wrappers for all jobs added to a cron using the `cron.WithChain` option: Install wrappers for individual jobs by explicitly wrapping them: Since the Cron service runs concurrently with the calling code, some amount of care must be taken to ensure proper synchronization. All cron methods are designed to be correctly synchronized as long as the caller ensures that invocations have a clear happens-before ordering between them. Cron defines a Logger interface that is a subset of the one defined in github.com/go-logr/logr. It has two logging levels (Info and Error), and parameters are key/value pairs. This makes it possible for cron logging to plug into structured logging systems. An adapter, [Verbose]PrintfLogger, is provided to wrap the standard library *log.Logger. For additional insight into Cron operations, verbose logging may be activated which will record job runs, scheduling decisions, and added or removed jobs. Activate it with a one-off logger as follows: Cron entries are stored in an array, sorted by their next activation time. Cron sleeps until the next job is due to be run. Upon waking:
Package cron implements a cron spec parser and job runner. Callers may register Funcs to be invoked on a given schedule. Cron will run them in their own goroutines. A cron expression represents a set of times, using 6 space-separated fields. Note: Month and Day-of-week field values are case insensitive. "SUN", "Sun", and "sun" are equally accepted. Asterisk ( * ) The asterisk indicates that the cron expression will match for all values of the field; e.g., using an asterisk in the 5th field (month) would indicate every month. Slash ( / ) Slashes are used to describe increments of ranges. For example 3-59/15 in the 1st field (minutes) would indicate the 3rd minute of the hour and every 15 minutes thereafter. The form "*\/..." is equivalent to the form "first-last/...", that is, an increment over the largest possible range of the field. The form "N/..." is accepted as meaning "N-MAX/...", that is, starting at N, use the increment until the end of that specific range. It does not wrap around. Comma ( , ) Commas are used to separate items of a list. For example, using "MON,WED,FRI" in the 5th field (day of week) would mean Mondays, Wednesdays and Fridays. Hyphen ( - ) Hyphens are used to define ranges. For example, 9-17 would indicate every hour between 9am and 5pm inclusive. Question mark ( ? ) Question mark may be used instead of '*' for leaving either day-of-month or day-of-week blank. You may use one of several pre-defined schedules in place of a cron expression. You may also schedule a job to execute at fixed intervals, starting at the time it's added or cron is run. This is supported by formatting the cron spec like this: where "duration" is a string accepted by time.ParseDuration (http://golang.org/pkg/time/#ParseDuration). For example, "@every 1h30m10s" would indicate a schedule that activates after 1 hour, 30 minutes, 10 seconds, and then every interval after that. Note: The interval does not take the job runtime into account. For example, if a job takes 3 minutes to run, and it is scheduled to run every 5 minutes, it will have only 2 minutes of idle time between each run. All interpretation and scheduling is done in the machine's local time zone (as provided by the Go time package (http://www.golang.org/pkg/time). Be aware that jobs scheduled during daylight-savings leap-ahead transitions will not be run! Since the Cron service runs concurrently with the calling code, some amount of care must be taken to ensure proper synchronization. All cron methods are designed to be correctly synchronized as long as the caller ensures that invocations have a clear happens-before ordering between them. Cron entries are stored in an array, sorted by their next activation time. Cron sleeps until the next job is due to be run. Upon waking:
Package validator implements value validations for structs and individual fields based on tags. It can also handle Cross-Field and Cross-Struct validation for nested structs and has the ability to dive into arrays and maps of any type. see more examples https://github.com/go-playground/validator/tree/v9/_examples Doing things this way is actually the way the standard library does, see the file.Open method here: The authors return type "error" to avoid the issue discussed in the following, where err is always != nil: Validator only InvalidValidationError for bad validation input, nil or ValidationErrors as type error; so, in your code all you need to do is check if the error returned is not nil, and if it's not check if error is InvalidValidationError ( if necessary, most of the time it isn't ) type cast it to type ValidationErrors like so err.(validator.ValidationErrors). Custom Validation functions can be added. Example: Cross-Field Validation can be done via the following tags: If, however, some custom cross-field validation is required, it can be done using a custom validation. Why not just have cross-fields validation tags (i.e. only eqcsfield and not eqfield)? The reason is efficiency. If you want to check a field within the same struct "eqfield" only has to find the field on the same struct (1 level). But, if we used "eqcsfield" it could be multiple levels down. Example: Multiple validators on a field will process in the order defined. Example: Bad Validator definitions are not handled by the library. Example: Baked In Cross-Field validation only compares fields on the same struct. If Cross-Field + Cross-Struct validation is needed you should implement your own custom validator. Comma (",") is the default separator of validation tags. If you wish to have a comma included within the parameter (i.e. excludesall=,) you will need to use the UTF-8 hex representation 0x2C, which is replaced in the code as a comma, so the above will become excludesall=0x2C. Pipe ("|") is the 'or' validation tags deparator. If you wish to have a pipe included within the parameter i.e. excludesall=| you will need to use the UTF-8 hex representation 0x7C, which is replaced in the code as a pipe, so the above will become excludesall=0x7C Here is a list of the current built in validators: Tells the validation to skip this struct field; this is particularly handy in ignoring embedded structs from being validated. (Usage: -) This is the 'or' operator allowing multiple validators to be used and accepted. (Usage: rbg|rgba) <-- this would allow either rgb or rgba colors to be accepted. This can also be combined with 'and' for example ( Usage: omitempty,rgb|rgba) When a field that is a nested struct is encountered, and contains this flag any validation on the nested struct will be run, but none of the nested struct fields will be validated. This is useful if inside of your program you know the struct will be valid, but need to verify it has been assigned. NOTE: only "required" and "omitempty" can be used on a struct itself. Same as structonly tag except that any struct level validations will not run. Allows conditional validation, for example if a field is not set with a value (Determined by the "required" validator) then other validation such as min or max won't run, but if a value is set validation will run. This tells the validator to dive into a slice, array or map and validate that level of the slice, array or map with the validation tags that follow. Multidimensional nesting is also supported, each level you wish to dive will require another dive tag. dive has some sub-tags, 'keys' & 'endkeys', please see the Keys & EndKeys section just below. Example #1 Example #2 Keys & EndKeys These are to be used together directly after the dive tag and tells the validator that anything between 'keys' and 'endkeys' applies to the keys of a map and not the values; think of it like the 'dive' tag, but for map keys instead of values. Multidimensional nesting is also supported, each level you wish to validate will require another 'keys' and 'endkeys' tag. These tags are only valid for maps. Example #1 Example #2 This validates that the value is not the data types default zero value. For numbers ensures value is not zero. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. The field under validation must be present and not empty only if any of the other specified fields are present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. Examples: The field under validation must be present and not empty only if all of the other specified fields are present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. Example: The field under validation must be present and not empty only when any of the other specified fields are not present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. Examples: The field under validation must be present and not empty only when all of the other specified fields are not present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. Example: This validates that the value is the default value and is almost the opposite of required. For numbers, length will ensure that the value is equal to the parameter given. For strings, it checks that the string length is exactly that number of characters. For slices, arrays, and maps, validates the number of items. For numbers, max will ensure that the value is less than or equal to the parameter given. For strings, it checks that the string length is at most that number of characters. For slices, arrays, and maps, validates the number of items. For numbers, min will ensure that the value is greater or equal to the parameter given. For strings, it checks that the string length is at least that number of characters. For slices, arrays, and maps, validates the number of items. For strings & numbers, eq will ensure that the value is equal to the parameter given. For slices, arrays, and maps, validates the number of items. For strings & numbers, ne will ensure that the value is not equal to the parameter given. For slices, arrays, and maps, validates the number of items. For strings, ints, and uints, oneof will ensure that the value is one of the values in the parameter. The parameter should be a list of values separated by whitespace. Values may be strings or numbers. For numbers, this will ensure that the value is greater than the parameter given. For strings, it checks that the string length is greater than that number of characters. For slices, arrays and maps it validates the number of items. Example #1 Example #2 (time.Time) For time.Time ensures the time value is greater than time.Now.UTC(). Same as 'min' above. Kept both to make terminology with 'len' easier. Example #1 Example #2 (time.Time) For time.Time ensures the time value is greater than or equal to time.Now.UTC(). For numbers, this will ensure that the value is less than the parameter given. For strings, it checks that the string length is less than that number of characters. For slices, arrays, and maps it validates the number of items. Example #1 Example #2 (time.Time) For time.Time ensures the time value is less than time.Now.UTC(). Same as 'max' above. Kept both to make terminology with 'len' easier. Example #1 Example #2 (time.Time) For time.Time ensures the time value is less than or equal to time.Now.UTC(). This will validate the field value against another fields value either within a struct or passed in field. Example #1: Example #2: Field Equals Another Field (relative) This does the same as eqfield except that it validates the field provided relative to the top level struct. This will validate the field value against another fields value either within a struct or passed in field. Examples: Field Does Not Equal Another Field (relative) This does the same as nefield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as gtfield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as gtefield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as ltfield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as ltefield except that it validates the field provided relative to the top level struct. This does the same as contains except for struct fields. It should only be used with string types. See the behavior of reflect.Value.String() for behavior on other types. This does the same as excludes except for struct fields. It should only be used with string types. See the behavior of reflect.Value.String() for behavior on other types. For arrays & slices, unique will ensure that there are no duplicates. For maps, unique will ensure that there are no duplicate values. For slices of struct, unique will ensure that there are no duplicate values in a field of the struct specified via a parameter. This validates that a string value contains ASCII alpha characters only This validates that a string value contains ASCII alphanumeric characters only This validates that a string value contains unicode alpha characters only This validates that a string value contains unicode alphanumeric characters only This validates that a string value contains a basic numeric value. basic excludes exponents etc... for integers or float it returns true. This validates that a string value contains a valid hexadecimal. This validates that a string value contains a valid hex color including hashtag (#) This validates that a string value contains a valid rgb color This validates that a string value contains a valid rgba color This validates that a string value contains a valid hsl color This validates that a string value contains a valid hsla color This validates that a string value contains a valid email This may not conform to all possibilities of any rfc standard, but neither does any email provider accept all possibilities. This validates that a string value contains a valid file path and that the file exists on the machine. This is done using os.Stat, which is a platform independent function. This validates that a string value contains a valid url This will accept any url the golang request uri accepts but must contain a schema for example http:// or rtmp:// This validates that a string value contains a valid uri This will accept any uri the golang request uri accepts This validataes that a string value contains a valid URN according to the RFC 2141 spec. This validates that a string value contains a valid base64 value. Although an empty string is valid base64 this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag. This validates that a string value contains a valid base64 URL safe value according the the RFC4648 spec. Although an empty string is a valid base64 URL safe value, this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag. This validates that a string value contains a valid bitcoin address. The format of the string is checked to ensure it matches one of the three formats P2PKH, P2SH and performs checksum validation. Bitcoin Bech32 Address (segwit) This validates that a string value contains a valid bitcoin Bech32 address as defined by bip-0173 (https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki) Special thanks to Pieter Wuille for providng reference implementations. This validates that a string value contains a valid ethereum address. The format of the string is checked to ensure it matches the standard Ethereum address format Full validation is blocked by https://github.com/golang/crypto/pull/28 This validates that a string value contains the substring value. This validates that a string value contains any Unicode code points in the substring value. This validates that a string value contains the supplied rune value. This validates that a string value does not contain the substring value. This validates that a string value does not contain any Unicode code points in the substring value. This validates that a string value does not contain the supplied rune value. This validates that a string value starts with the supplied string value This validates that a string value ends with the supplied string value This validates that a string value contains a valid isbn10 or isbn13 value. This validates that a string value contains a valid isbn10 value. This validates that a string value contains a valid isbn13 value. This validates that a string value contains a valid UUID. Uppercase UUID values will not pass - use `uuid_rfc4122` instead. This validates that a string value contains a valid version 3 UUID. Uppercase UUID values will not pass - use `uuid3_rfc4122` instead. This validates that a string value contains a valid version 4 UUID. Uppercase UUID values will not pass - use `uuid4_rfc4122` instead. This validates that a string value contains a valid version 5 UUID. Uppercase UUID values will not pass - use `uuid5_rfc4122` instead. This validates that a string value contains only ASCII characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains only printable ASCII characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains one or more multibyte characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains a valid DataURI. NOTE: this will also validate that the data portion is valid base64 This validates that a string value contains a valid latitude. This validates that a string value contains a valid longitude. This validates that a string value contains a valid U.S. Social Security Number. This validates that a string value contains a valid IP Address. This validates that a string value contains a valid v4 IP Address. This validates that a string value contains a valid v6 IP Address. This validates that a string value contains a valid CIDR Address. This validates that a string value contains a valid v4 CIDR Address. This validates that a string value contains a valid v6 CIDR Address. This validates that a string value contains a valid resolvable TCP Address. This validates that a string value contains a valid resolvable v4 TCP Address. This validates that a string value contains a valid resolvable v6 TCP Address. This validates that a string value contains a valid resolvable UDP Address. This validates that a string value contains a valid resolvable v4 UDP Address. This validates that a string value contains a valid resolvable v6 UDP Address. This validates that a string value contains a valid resolvable IP Address. This validates that a string value contains a valid resolvable v4 IP Address. This validates that a string value contains a valid resolvable v6 IP Address. This validates that a string value contains a valid Unix Address. This validates that a string value contains a valid MAC Address. Note: See Go's ParseMAC for accepted formats and types: This validates that a string value is a valid Hostname according to RFC 952 https://tools.ietf.org/html/rfc952 This validates that a string value is a valid Hostname according to RFC 1123 https://tools.ietf.org/html/rfc1123 Full Qualified Domain Name (FQDN) This validates that a string value contains a valid FQDN. This validates that a string value appears to be an HTML element tag including those described at https://developer.mozilla.org/en-US/docs/Web/HTML/Element This validates that a string value is a proper character reference in decimal or hexadecimal format This validates that a string value is percent-encoded (URL encoded) according to https://tools.ietf.org/html/rfc3986#section-2.1 This validates that a string value contains a valid directory and that it exists on the machine. This is done using os.Stat, which is a platform independent function. NOTE: When returning an error, the tag returned in "FieldError" will be the alias tag unless the dive tag is part of the alias. Everything after the dive tag is not reported as the alias tag. Also, the "ActualTag" in the before case will be the actual tag within the alias that failed. Here is a list of the current built in alias tags: Validator notes: A collection of validation rules that are frequently needed but are more complex than the ones found in the baked in validators. A non standard validator must be registered manually like you would with your own custom validation functions. Example of registration and use: Here is a list of the current non standard validators: This package panics when bad input is provided, this is by design, bad code like that should not make it to production.
Package pq is a pure Go Postgres driver for the database/sql package. In most cases clients will use the database/sql package instead of using this package directly. For example: You can also connect to a database using a URL. For example: Similarly to libpq, when establishing a connection using pq you are expected to supply a connection string containing zero or more parameters. A subset of the connection parameters supported by libpq are also supported by pq. Additionally, pq also lets you specify run-time parameters (such as search_path or work_mem) directly in the connection string. This is different from libpq, which does not allow run-time parameters in the connection string, instead requiring you to supply them in the options parameter. For compatibility with libpq, the following special connection parameters are supported: Valid values for sslmode are: See http://www.postgresql.org/docs/current/static/libpq-connect.html#LIBPQ-CONNSTRING for more information about connection string parameters. Use single quotes for values that contain whitespace: A backslash will escape the next character in values: Note that the connection parameter client_encoding (which sets the text encoding for the connection) may be set but must be "UTF8", matching with the same rules as Postgres. It is an error to provide any other value. In addition to the parameters listed above, any run-time parameter that can be set at backend start time can be set in the connection string. For more information, see http://www.postgresql.org/docs/current/static/runtime-config.html. Most environment variables as specified at http://www.postgresql.org/docs/current/static/libpq-envars.html supported by libpq are also supported by pq. If any of the environment variables not supported by pq are set, pq will panic during connection establishment. Environment variables have a lower precedence than explicitly provided connection parameters. The pgpass mechanism as described in http://www.postgresql.org/docs/current/static/libpq-pgpass.html is supported, but on Windows PGPASSFILE must be specified explicitly. database/sql does not dictate any specific format for parameter markers in query strings, and pq uses the Postgres-native ordinal markers, as shown above. The same marker can be reused for the same parameter: pq does not support the LastInsertId() method of the Result type in database/sql. To return the identifier of an INSERT (or UPDATE or DELETE), use the Postgres RETURNING clause with a standard Query or QueryRow call: For more details on RETURNING, see the Postgres documentation: For additional instructions on querying see the documentation for the database/sql package. Parameters pass through driver.DefaultParameterConverter before they are handled by this package. When the binary_parameters connection option is enabled, []byte values are sent directly to the backend as data in binary format. This package returns the following types for values from the PostgreSQL backend: All other types are returned directly from the backend as []byte values in text format. pq may return errors of type *pq.Error which can be interrogated for error details: See the pq.Error type for details. You can perform bulk imports by preparing a statement returned by pq.CopyIn (or pq.CopyInSchema) in an explicit transaction (sql.Tx). The returned statement handle can then be repeatedly "executed" to copy data into the target table. After all data has been processed you should call Exec() once with no arguments to flush all buffered data. Any call to Exec() might return an error which should be handled appropriately, but because of the internal buffering an error returned by Exec() might not be related to the data passed in the call that failed. CopyIn uses COPY FROM internally. It is not possible to COPY outside of an explicit transaction in pq. Usage example: PostgreSQL supports a simple publish/subscribe model over database connections. See http://www.postgresql.org/docs/current/static/sql-notify.html for more information about the general mechanism. To start listening for notifications, you first have to open a new connection to the database by calling NewListener. This connection can not be used for anything other than LISTEN / NOTIFY. Calling Listen will open a "notification channel"; once a notification channel is open, a notification generated on that channel will effect a send on the Listener.Notify channel. A notification channel will remain open until Unlisten is called, though connection loss might result in some notifications being lost. To solve this problem, Listener sends a nil pointer over the Notify channel any time the connection is re-established following a connection loss. The application can get information about the state of the underlying connection by setting an event callback in the call to NewListener. A single Listener can safely be used from concurrent goroutines, which means that there is often no need to create more than one Listener in your application. However, a Listener is always connected to a single database, so you will need to create a new Listener instance for every database you want to receive notifications in. The channel name in both Listen and Unlisten is case sensitive, and can contain any characters legal in an identifier (see http://www.postgresql.org/docs/current/static/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS for more information). Note that the channel name will be truncated to 63 bytes by the PostgreSQL server. You can find a complete, working example of Listener usage at https://godoc.org/github.com/lib/pq/example/listen. If you need support for Kerberos authentication, add the following to your main package: This package is in a separate module so that users who don't need Kerberos don't have to download unnecessary dependencies. When imported, additional connection string parameters are supported:
Package cloud is the root of the packages used to access Google Cloud Services. See https://pkg.go.dev/cloud.google.com/go for a full list of sub-modules. All clients in sub-packages are configurable via client options. These options are described here: https://pkg.go.dev/google.golang.org/api/option. Endpoint configuration is used to specify the URL to which requests are sent. It is used for services that support or require regional endpoints, as well as for other use cases such as testing against fake servers. For example, the Vertex AI service recommends that you configure the endpoint to the location with the features you want that is closest to your physical location or the location of your users. There is no global endpoint for Vertex AI. See Vertex AI - Locations for more details. The following example demonstrates configuring a Vertex AI client with a regional endpoint: All of the clients support authentication via Google Application Default Credentials, or by providing a JSON key file for a Service Account. See examples below. Google Application Default Credentials (ADC) is the recommended way to authorize and authenticate clients. For information on how to create and obtain Application Default Credentials, see https://cloud.google.com/docs/authentication/production. If you have your environment configured correctly you will not need to pass any extra information to the client libraries. Here is an example of a client using ADC to authenticate: You can use a file with credentials to authenticate and authorize, such as a JSON key file associated with a Google service account. Service Account keys can be created and downloaded from https://console.cloud.google.com/iam-admin/serviceaccounts. This example uses the Secret Manger client, but the same steps apply to the all other client libraries this package as well. Example: In some cases (for instance, you don't want to store secrets on disk), you can create credentials from in-memory JSON and use the WithCredentials option. This example uses the Secret Manager client, but the same steps apply to all other client libraries as well. Note that scopes can be found at https://developers.google.com/identity/protocols/oauth2/scopes, and are also provided in all auto-generated libraries: for example, cloud.google.com/go/secretmanager/apiv1 provides DefaultAuthScopes. Example: By default, non-streaming methods, like Create or Get, will have a default deadline applied to the context provided at call time, unless a context deadline is already set. Streaming methods have no default deadline and will run indefinitely. To set timeouts or arrange for cancellation, use context. Transient errors will be retried when correctness allows. Here is an example of setting a timeout for an RPC using context.WithTimeout: Here is an example of setting a timeout for an RPC using github.com/googleapis/gax-go/v2.WithTimeout: Here is an example of how to arrange for an RPC to be canceled, use context.WithCancel: Do not attempt to control the initial connection (dialing) of a service by setting a timeout on the context passed to NewClient. Dialing is non-blocking, so timeouts would be ineffective and would only interfere with credential refreshing, which uses the same context. Regardless of which transport is used, request headers can be set in the same way using [`callctx.SetHeaders`]setheaders. Here is a generic example: ## Google-reserved headers There are a some header keys that Google reserves for internal use that must not be ovewritten. The following header keys are broadly considered reserved and should not be conveyed by client library users unless instructed to do so: * `x-goog-api-client` * `x-goog-request-params` Be sure to check the individual package documentation for other service-specific reserved headers. For example, Storage supports a specific auditing header that is mentioned in that [module's documentation]storagedocs. ## Google Cloud system parameters Google Cloud services respect system parameterssystem parameters that can be used to augment request and/or response behavior. For the most part, they are not needed when using one of the enclosed client libraries. However, those that may be necessary are made available via the [`callctx`]callctx package. If not present there, consider opening an issue on that repo to request a new constant. Connection pooling differs in clients based on their transport. Cloud clients either rely on HTTP or gRPC transports to communicate with Google Cloud. Cloud clients that use HTTP rely on the underlying HTTP transport to cache connections for later re-use. These are cached to the http.MaxIdleConns and http.MaxIdleConnsPerHost settings in http.DefaultTransport by default. For gRPC clients, connection pooling is configurable. Users of Cloud Client Libraries may specify option.WithGRPCConnectionPool(n) as a client option to NewClient calls. This configures the underlying gRPC connections to be pooled and accessed in a round robin fashion. Minimal container images like Alpine lack CA certificates. This causes RPCs to appear to hang, because gRPC retries indefinitely. See https://github.com/googleapis/google-cloud-go/issues/928 for more information. For tips on how to write tests against code that calls into our libraries check out our Debugging Guide. For tips on how to write tests against code that calls into our libraries check out our Testing Guide. Most of the errors returned by the generated clients are wrapped in an github.com/googleapis/gax-go/v2/apierror.APIError and can be further unwrapped into a google.golang.org/grpc/status.Status or google.golang.org/api/googleapi.Error depending on the transport used to make the call (gRPC or REST). Converting your errors to these types can be a useful way to get more information about what went wrong while debugging. APIError gives access to specific details in the error. The transport-specific errors can still be unwrapped using the APIError. If the gRPC transport was used, the google.golang.org/grpc/status.Status can still be parsed using the google.golang.org/grpc/status.FromError function. Semver is used to communicate stability of the sub-modules of this package. Note, some stable sub-modules do contain packages, and sometimes features, that are considered unstable. If something is unstable it will be explicitly labeled as such. Example of package does in an unstable package: Clients that contain alpha and beta in their import path may change or go away without notice. Clients marked stable will maintain compatibility with future versions for as long as we can reasonably sustain. Incompatible changes might be made in some situations, including:
Package api is the root of the packages used to access Google Cloud Services. See https://godoc.org/google.golang.org/api for a full list of sub-packages. Within api there exist numerous clients which connect to Google APIs, and various utility packages. All clients in sub-packages are configurable via client options. These options are described here: https://godoc.org/google.golang.org/api/option. All the clients in sub-packages support authentication via Google Application Default Credentials (see https://cloud.google.com/docs/authentication/production), or by providing a JSON key file for a Service Account. See the authentication examples in https://godoc.org/google.golang.org/api/transport for more details. Due to the auto-generated nature of this collection of libraries, complete APIs or specific versions can appear or go away without notice. As a result, you should always locally vendor any API(s) that your code relies upon. Google APIs follow semver as specified by https://cloud.google.com/apis/design/versioning. The code generator and the code it produces - the libraries in the google.golang.org/api/... subpackages - are beta. Note that versioning and stability is strictly not communicated through Go modules. Go modules are used only for dependency management. Many parameters are specified using ints. However, underlying APIs might operate on a finer granularity, expecting int64, int32, uint64, or uint32, all of whom have different maximum values. Subsequently, specifying an int parameter in one of these clients may result in an error from the API because the value is too large. To see the exact type of int that the API expects, you can inspect the API's discovery doc. A global catalogue pointing to the discovery doc of APIs can be found at https://www.googleapis.com/discovery/v1/apis. This field can be found on all Request/Response structs in the generated clients. All of these types have the JSON `omitempty` field tag present on their fields. This means if a type is set to its default value it will not be marshalled. Sometimes you may actually want to send a default value, for instance sending an int of `0`. In this case you can override the `omitempty` feature by adding the field name to the `ForceSendFields` slice. See docs on any struct for more details. This may be used to include empty fields in Patch requests. This field can be found on all Request/Response structs in the generated clients. It can be be used to send JSON null values for the listed fields. By default, fields with empty values are omitted from API requests because of the presence of the `omitempty` field tag on all fields. However, any field with an empty value appearing in NullFields will be sent to the server as null. It is an error if a field in this list has a non-empty value. This may be used to include null fields in Patch requests. An error returned by a client's Do method may be cast to a *googleapi.Error or unwrapped to an *apierror.APIError. The https://pkg.go.dev/google.golang.org/api/googleapi#Error type is useful for getting the HTTP status code: The https://pkg.go.dev/github.com/googleapis/gax-go/v2/apierror#APIError type is useful for inspecting structured details of the underlying API response, such as the reason for the error and the error domain, which is typically the registered service name of the tool or product that generated the error: If an API call returns an Operation, that means it could take some time to complete the work initiated by the API call. Applications that are interested in the end result of the operation they initiated should wait until the Operation.Done field indicates it is finished. To do this, use the service's Operation client, and a loop, like so:
Package storage provides an easy way to work with Google Cloud Storage. Google Cloud Storage stores data in named objects, which are grouped into buckets. More information about Google Cloud Storage is available at https://cloud.google.com/storage/docs. See https://pkg.go.dev/cloud.google.com/go for authentication, timeouts, connection pooling and similar aspects of this package. To start working with this package, create a Client: The client will use your default application credentials. Clients should be reused instead of created as needed. The methods of Client are safe for concurrent use by multiple goroutines. You may configure the client by passing in options from the google.golang.org/api/option package. You may also use options defined in this package, such as WithJSONReads. If you only wish to access public data, you can create an unauthenticated client with To use an emulator with this library, you can set the STORAGE_EMULATOR_HOST environment variable to the address at which your emulator is running. This will send requests to that address instead of to Cloud Storage. You can then create and use a client as usual: Please note that there is no official emulator for Cloud Storage. A Google Cloud Storage bucket is a collection of objects. To work with a bucket, make a bucket handle: A handle is a reference to a bucket. You can have a handle even if the bucket doesn't exist yet. To create a bucket in Google Cloud Storage, call BucketHandle.Create: Note that although buckets are associated with projects, bucket names are global across all projects. Each bucket has associated metadata, represented in this package by BucketAttrs. The third argument to BucketHandle.Create allows you to set the initial BucketAttrs of a bucket. To retrieve a bucket's attributes, use BucketHandle.Attrs: An object holds arbitrary data as a sequence of bytes, like a file. You refer to objects using a handle, just as with buckets, but unlike buckets you don't explicitly create an object. Instead, the first time you write to an object it will be created. You can use the standard Go io.Reader and io.Writer interfaces to read and write object data: Objects also have attributes, which you can fetch with ObjectHandle.Attrs: Listing objects in a bucket is done with the BucketHandle.Objects method: Objects are listed lexicographically by name. To filter objects lexicographically, [Query.StartOffset] and/or [Query.EndOffset] can be used: If only a subset of object attributes is needed when listing, specifying this subset using Query.SetAttrSelection may speed up the listing process: Both objects and buckets have ACLs (Access Control Lists). An ACL is a list of ACLRules, each of which specifies the role of a user, group or project. ACLs are suitable for fine-grained control, but you may prefer using IAM to control access at the project level (see Cloud Storage IAM docs. To list the ACLs of a bucket or object, obtain an ACLHandle and call ACLHandle.List: You can also set and delete ACLs. Every object has a generation and a metageneration. The generation changes whenever the content changes, and the metageneration changes whenever the metadata changes. Conditions let you check these values before an operation; the operation only executes if the conditions match. You can use conditions to prevent race conditions in read-modify-write operations. For example, say you've read an object's metadata into objAttrs. Now you want to write to that object, but only if its contents haven't changed since you read it. Here is how to express that: You can obtain a URL that lets anyone read or write an object for a limited time. Signing a URL requires credentials authorized to sign a URL. To use the same authentication that was used when instantiating the Storage client, use BucketHandle.SignedURL. You can also sign a URL without creating a client. See the documentation of SignedURL for details. A type of signed request that allows uploads through HTML forms directly to Cloud Storage with temporary permission. Conditions can be applied to restrict how the HTML form is used and exercised by a user. For more information, please see the XML POST Object docs as well as the documentation of BucketHandle.GenerateSignedPostPolicyV4. If the GoogleAccessID and PrivateKey option fields are not provided, they will be automatically detected by BucketHandle.SignedURL and BucketHandle.GenerateSignedPostPolicyV4 if any of the following are true: Detecting GoogleAccessID may not be possible if you are authenticated using a token source or using option.WithHTTPClient. In this case, you can provide a service account email for GoogleAccessID and the client will attempt to sign the URL or Post Policy using that service account. To generate the signature, you must have: Errors returned by this client are often of the type googleapi.Error. These errors can be introspected for more information by using errors.As with the richer googleapi.Error type. For example: Methods in this package may retry calls that fail with transient errors. Retrying continues indefinitely unless the controlling context is canceled, the client is closed, or a non-transient error is received. To stop retries from continuing, use context timeouts or cancellation. The retry strategy in this library follows best practices for Cloud Storage. By default, operations are retried only if they are idempotent, and exponential backoff with jitter is employed. In addition, errors are only retried if they are defined as transient by the service. See the Cloud Storage retry docs for more information. Users can configure non-default retry behavior for a single library call (using BucketHandle.Retryer and ObjectHandle.Retryer) or for all calls made by a client (using Client.SetRetry). For example: You can add custom headers to any API call made by this package by using callctx.SetHeaders on the context which is passed to the method. For example, to add a custom audit logging header: This package includes support for the Cloud Storage gRPC API. The implementation uses gRPC rather than the Default JSON & XML APIs to make requests to Cloud Storage. The Go Storage gRPC client is generally available. The Notifications, Serivce Account HMAC and GetServiceAccount RPCs are not supported through the gRPC client. To create a client which will use gRPC, use the alternate constructor: Using the gRPC API inside GCP with a bucket in the same region can allow for Direct Connectivity (enabling requests to skip some proxy steps and reducing response latency). A warning is emmitted if gRPC is not used within GCP to warn that Direct Connectivity could not be initialized. Direct Connectivity is not required to access the gRPC API. Dependencies for the gRPC API may slightly increase the size of binaries for applications depending on this package. If you are not using gRPC, you can use the build tag `disable_grpc_modules` to opt out of these dependencies and reduce the binary size. The gRPC client emits metrics by default and will export the gRPC telemetry discussed in gRFC/66 and gRFC/78 to Google Cloud Monitoring. The metrics are accessible through Cloud Monitoring API and you incur no additional cost for publishing the metrics. Google Cloud Support can use this information to more quickly diagnose problems related to GCS and gRPC. Sending this data does not incur any billing charges, and requires minimal CPU (a single RPC every minute) or memory (a few KiB to batch the telemetry). To access the metrics you can view them through Cloud Monitoring metric explorer with the prefix `storage.googleapis.com/client`. Metrics are emitted every minute. You can disable metrics using the following example when creating a new gRPC client using WithDisabledClientMetrics. The metrics exporter uses Cloud Monitoring API which determines project ID and credentials doing the following: * Project ID is determined using OTel Resource Detector for the environment otherwise it falls back to the project provided by google.FindCredentials. * Credentials are determined using Application Default Credentials. The principal must have `roles/monitoring.metricWriter` role granted. If not a logged warning will be emitted. Subsequent are silenced to prevent noisy logs. Certain control plane and long-running operations for Cloud Storage (including Folder and Managed Folder operations) are supported via the autogenerated Storage Control client, which is available as a subpackage in this module. See package docs at cloud.google.com/go/storage/control/apiv2 or reference the Storage Control API docs.
Package validator implements value validations for structs and individual fields based on tags. It can also handle Cross-Field and Cross-Struct validation for nested structs and has the ability to dive into arrays and maps of any type. Why not a better error message? Because this library intends for you to handle your own error messages. Why should I handle my own errors? Many reasons. We built an internationalized application and needed to know the field, and what validation failed so we could provide a localized error. Doing things this way is actually the way the standard library does, see the file.Open method here: The authors return type "error" to avoid the issue discussed in the following, where err is always != nil: Validator only returns nil or ValidationErrors as type error; so, in your code all you need to do is check if the error returned is not nil, and if it's not type cast it to type ValidationErrors like so err.(validator.ValidationErrors). Custom functions can be added. Example: Cross-Field Validation can be done via the following tags: If, however, some custom cross-field validation is required, it can be done using a custom validation. Why not just have cross-fields validation tags (i.e. only eqcsfield and not eqfield)? The reason is efficiency. If you want to check a field within the same struct "eqfield" only has to find the field on the same struct (1 level). But, if we used "eqcsfield" it could be multiple levels down. Example: Multiple validators on a field will process in the order defined. Example: Bad Validator definitions are not handled by the library. Example: Baked In Cross-Field validation only compares fields on the same struct. If Cross-Field + Cross-Struct validation is needed you should implement your own custom validator. Comma (",") is the default separator of validation tags. If you wish to have a comma included within the parameter (i.e. excludesall=,) you will need to use the UTF-8 hex representation 0x2C, which is replaced in the code as a comma, so the above will become excludesall=0x2C. Pipe ("|") is the default separator of validation tags. If you wish to have a pipe included within the parameter i.e. excludesall=| you will need to use the UTF-8 hex representation 0x7C, which is replaced in the code as a pipe, so the above will become excludesall=0x7C Here is a list of the current built in validators: Tells the validation to skip this struct field; this is particularly handy in ignoring embedded structs from being validated. (Usage: -) This is the 'or' operator allowing multiple validators to be used and accepted. (Usage: rbg|rgba) <-- this would allow either rgb or rgba colors to be accepted. This can also be combined with 'and' for example ( Usage: omitempty,rgb|rgba) When a field that is a nested struct is encountered, and contains this flag any validation on the nested struct will be run, but none of the nested struct fields will be validated. This is usefull if inside of you program you know the struct will be valid, but need to verify it has been assigned. NOTE: only "required" and "omitempty" can be used on a struct itself. Same as structonly tag except that any struct level validations will not run. Is a special tag without a validation function attached. It is used when a field is a Pointer, Interface or Invalid and you wish to validate that it exists. Example: want to ensure a bool exists if you define the bool as a pointer and use exists it will ensure there is a value; couldn't use required as it would fail when the bool was false. exists will fail is the value is a Pointer, Interface or Invalid and is nil. Allows conditional validation, for example if a field is not set with a value (Determined by the "required" validator) then other validation such as min or max won't run, but if a value is set validation will run. This tells the validator to dive into a slice, array or map and validate that level of the slice, array or map with the validation tags that follow. Multidimensional nesting is also supported, each level you wish to dive will require another dive tag. Example #1 Example #2 This validates that the value is not the data types default zero value. For numbers ensures value is not zero. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. For numbers, max will ensure that the value is equal to the parameter given. For strings, it checks that the string length is exactly that number of characters. For slices, arrays, and maps, validates the number of items. For numbers, max will ensure that the value is less than or equal to the parameter given. For strings, it checks that the string length is at most that number of characters. For slices, arrays, and maps, validates the number of items. For numbers, min will ensure that the value is greater or equal to the parameter given. For strings, it checks that the string length is at least that number of characters. For slices, arrays, and maps, validates the number of items. For strings & numbers, eq will ensure that the value is equal to the parameter given. For slices, arrays, and maps, validates the number of items. For strings & numbers, ne will ensure that the value is not equal to the parameter given. For slices, arrays, and maps, validates the number of items. For numbers, this will ensure that the value is greater than the parameter given. For strings, it checks that the string length is greater than that number of characters. For slices, arrays and maps it validates the number of items. Example #1 Example #2 (time.Time) For time.Time ensures the time value is greater than time.Now.UTC(). Same as 'min' above. Kept both to make terminology with 'len' easier. Example #1 Example #2 (time.Time) For time.Time ensures the time value is greater than or equal to time.Now.UTC(). For numbers, this will ensure that the value is less than the parameter given. For strings, it checks that the string length is less than that number of characters. For slices, arrays, and maps it validates the number of items. Example #1 Example #2 (time.Time) For time.Time ensures the time value is less than time.Now.UTC(). Same as 'max' above. Kept both to make terminology with 'len' easier. Example #1 Example #2 (time.Time) For time.Time ensures the time value is less than or equal to time.Now.UTC(). This will validate the field value against another fields value either within a struct or passed in field. Example #1: Example #2: Field Equals Another Field (relative) This does the same as eqfield except that it validates the field provided relative to the top level struct. This will validate the field value against another fields value either within a struct or passed in field. Examples: Field Does Not Equal Another Field (relative) This does the same as nefield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as gtfield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as gtefield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as ltfield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as ltefield except that it validates the field provided relative to the top level struct. This validates that a string value contains alpha characters only This validates that a string value contains alphanumeric characters only This validates that a string value contains a basic numeric value. basic excludes exponents etc... This validates that a string value contains a valid hexadecimal. This validates that a string value contains a valid hex color including hashtag (#) This validates that a string value contains a valid rgb color This validates that a string value contains a valid rgba color This validates that a string value contains a valid hsl color This validates that a string value contains a valid hsla color This validates that a string value contains a valid email This may not conform to all possibilities of any rfc standard, but neither does any email provider accept all posibilities. This validates that a string value contains a valid url This will accept any url the golang request uri accepts but must contain a schema for example http:// or rtmp:// This validates that a string value contains a valid uri This will accept any uri the golang request uri accepts This validates that a string value contains a valid base64 value. Although an empty string is valid base64 this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag. This validates that a string value contains the substring value. This validates that a string value contains any Unicode code points in the substring value. This validates that a string value contains the supplied rune value. This validates that a string value does not contain the substring value. This validates that a string value does not contain any Unicode code points in the substring value. This validates that a string value does not contain the supplied rune value. This validates that a string value contains a valid isbn10 or isbn13 value. This validates that a string value contains a valid isbn10 value. This validates that a string value contains a valid isbn13 value. This validates that a string value contains a valid UUID. This validates that a string value contains a valid version 3 UUID. This validates that a string value contains a valid version 4 UUID. This validates that a string value contains a valid version 5 UUID. This validates that a string value contains only ASCII characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains only printable ASCII characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains one or more multibyte characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains a valid DataURI. NOTE: this will also validate that the data portion is valid base64 This validates that a string value contains a valid latitude. This validates that a string value contains a valid longitude. This validates that a string value contains a valid U.S. Social Security Number. This validates that a string value contains a valid IP Adress. This validates that a string value contains a valid v4 IP Adress. This validates that a string value contains a valid v6 IP Adress. This validates that a string value contains a valid CIDR Adress. This validates that a string value contains a valid v4 CIDR Adress. This validates that a string value contains a valid v6 CIDR Adress. This validates that a string value contains a valid resolvable TCP Adress. This validates that a string value contains a valid resolvable v4 TCP Adress. This validates that a string value contains a valid resolvable v6 TCP Adress. This validates that a string value contains a valid resolvable UDP Adress. This validates that a string value contains a valid resolvable v4 UDP Adress. This validates that a string value contains a valid resolvable v6 UDP Adress. This validates that a string value contains a valid resolvable IP Adress. This validates that a string value contains a valid resolvable v4 IP Adress. This validates that a string value contains a valid resolvable v6 IP Adress. This validates that a string value contains a valid Unix Adress. This validates that a string value contains a valid MAC Adress. Note: See Go's ParseMAC for accepted formats and types: NOTE: When returning an error, the tag returned in "FieldError" will be the alias tag unless the dive tag is part of the alias. Everything after the dive tag is not reported as the alias tag. Also, the "ActualTag" in the before case will be the actual tag within the alias that failed. Here is a list of the current built in alias tags: Validator notes: This package panics when bad input is provided, this is by design, bad code like that should not make it to production.
test.go is a "Go script" for running Vitess tests. It runs each test in its own Docker container for hermeticity and (potentially) parallelism. If a test fails, this script will save the output in _test/ and continue with other tests. Before using it, you should have Docker 1.5+ installed, and have your user in the group that lets you run the docker command without sudo. The first time you run against a given flavor, it may take some time for the corresponding bootstrap image (vitess/bootstrap:<flavor>) to be downloaded. It is meant to be run from the Vitess root, like so: For a list of options, run:
Package validator implements value validations for structs and individual fields based on tags. It can also handle Cross-Field and Cross-Struct validation for nested structs and has the ability to dive into arrays and maps of any type. see more examples https://github.com/go-playground/validator/tree/v9/_examples Doing things this way is actually the way the standard library does, see the file.Open method here: The authors return type "error" to avoid the issue discussed in the following, where err is always != nil: Validator only InvalidValidationError for bad validation input, nil or ValidationErrors as type error; so, in your code all you need to do is check if the error returned is not nil, and if it's not check if error is InvalidValidationError ( if necessary, most of the time it isn't ) type cast it to type ValidationErrors like so err.(validator.ValidationErrors). Custom Validation functions can be added. Example: Cross-Field Validation can be done via the following tags: If, however, some custom cross-field validation is required, it can be done using a custom validation. Why not just have cross-fields validation tags (i.e. only eqcsfield and not eqfield)? The reason is efficiency. If you want to check a field within the same struct "eqfield" only has to find the field on the same struct (1 level). But, if we used "eqcsfield" it could be multiple levels down. Example: Multiple validators on a field will process in the order defined. Example: Bad Validator definitions are not handled by the library. Example: Baked In Cross-Field validation only compares fields on the same struct. If Cross-Field + Cross-Struct validation is needed you should implement your own custom validator. Comma (",") is the default separator of validation tags. If you wish to have a comma included within the parameter (i.e. excludesall=,) you will need to use the UTF-8 hex representation 0x2C, which is replaced in the code as a comma, so the above will become excludesall=0x2C. Pipe ("|") is the 'or' validation tags deparator. If you wish to have a pipe included within the parameter i.e. excludesall=| you will need to use the UTF-8 hex representation 0x7C, which is replaced in the code as a pipe, so the above will become excludesall=0x7C Here is a list of the current built in validators: Tells the validation to skip this struct field; this is particularly handy in ignoring embedded structs from being validated. (Usage: -) This is the 'or' operator allowing multiple validators to be used and accepted. (Usage: rbg|rgba) <-- this would allow either rgb or rgba colors to be accepted. This can also be combined with 'and' for example ( Usage: omitempty,rgb|rgba) When a field that is a nested struct is encountered, and contains this flag any validation on the nested struct will be run, but none of the nested struct fields will be validated. This is useful if inside of your program you know the struct will be valid, but need to verify it has been assigned. NOTE: only "required" and "omitempty" can be used on a struct itself. Same as structonly tag except that any struct level validations will not run. Allows conditional validation, for example if a field is not set with a value (Determined by the "required" validator) then other validation such as min or max won't run, but if a value is set validation will run. This tells the validator to dive into a slice, array or map and validate that level of the slice, array or map with the validation tags that follow. Multidimensional nesting is also supported, each level you wish to dive will require another dive tag. dive has some sub-tags, 'keys' & 'endkeys', please see the Keys & EndKeys section just below. Example #1 Example #2 Keys & EndKeys These are to be used together directly after the dive tag and tells the validator that anything between 'keys' and 'endkeys' applies to the keys of a map and not the values; think of it like the 'dive' tag, but for map keys instead of values. Multidimensional nesting is also supported, each level you wish to validate will require another 'keys' and 'endkeys' tag. These tags are only valid for maps. Example #1 Example #2 This validates that the value is not the data types default zero value. For numbers ensures value is not zero. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. The field under validation must be present and not empty only if any of the other specified fields are present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. Examples: The field under validation must be present and not empty only if all of the other specified fields are present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. Example: The field under validation must be present and not empty only when any of the other specified fields are not present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. Examples: The field under validation must be present and not empty only when all of the other specified fields are not present. For strings ensures value is not "". For slices, maps, pointers, interfaces, channels and functions ensures the value is not nil. Example: This validates that the value is the default value and is almost the opposite of required. For numbers, length will ensure that the value is equal to the parameter given. For strings, it checks that the string length is exactly that number of characters. For slices, arrays, and maps, validates the number of items. For numbers, max will ensure that the value is less than or equal to the parameter given. For strings, it checks that the string length is at most that number of characters. For slices, arrays, and maps, validates the number of items. For numbers, min will ensure that the value is greater or equal to the parameter given. For strings, it checks that the string length is at least that number of characters. For slices, arrays, and maps, validates the number of items. For strings & numbers, eq will ensure that the value is equal to the parameter given. For slices, arrays, and maps, validates the number of items. For strings & numbers, ne will ensure that the value is not equal to the parameter given. For slices, arrays, and maps, validates the number of items. For strings, ints, and uints, oneof will ensure that the value is one of the values in the parameter. The parameter should be a list of values separated by whitespace. Values may be strings or numbers. For numbers, this will ensure that the value is greater than the parameter given. For strings, it checks that the string length is greater than that number of characters. For slices, arrays and maps it validates the number of items. Example #1 Example #2 (time.Time) For time.Time ensures the time value is greater than time.Now.UTC(). Same as 'min' above. Kept both to make terminology with 'len' easier. Example #1 Example #2 (time.Time) For time.Time ensures the time value is greater than or equal to time.Now.UTC(). For numbers, this will ensure that the value is less than the parameter given. For strings, it checks that the string length is less than that number of characters. For slices, arrays, and maps it validates the number of items. Example #1 Example #2 (time.Time) For time.Time ensures the time value is less than time.Now.UTC(). Same as 'max' above. Kept both to make terminology with 'len' easier. Example #1 Example #2 (time.Time) For time.Time ensures the time value is less than or equal to time.Now.UTC(). This will validate the field value against another fields value either within a struct or passed in field. Example #1: Example #2: Field Equals Another Field (relative) This does the same as eqfield except that it validates the field provided relative to the top level struct. This will validate the field value against another fields value either within a struct or passed in field. Examples: Field Does Not Equal Another Field (relative) This does the same as nefield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as gtfield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as gtefield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as ltfield except that it validates the field provided relative to the top level struct. Only valid for Numbers and time.Time types, this will validate the field value against another fields value either within a struct or passed in field. usage examples are for validation of a Start and End date: Example #1: Example #2: This does the same as ltefield except that it validates the field provided relative to the top level struct. This does the same as contains except for struct fields. It should only be used with string types. See the behavior of reflect.Value.String() for behavior on other types. This does the same as excludes except for struct fields. It should only be used with string types. See the behavior of reflect.Value.String() for behavior on other types. For arrays & slices, unique will ensure that there are no duplicates. For maps, unique will ensure that there are no duplicate values. For slices of struct, unique will ensure that there are no duplicate values in a field of the struct specified via a parameter. This validates that a string value contains ASCII alpha characters only This validates that a string value contains ASCII alphanumeric characters only This validates that a string value contains unicode alpha characters only This validates that a string value contains unicode alphanumeric characters only This validates that a string value contains a basic numeric value. basic excludes exponents etc... for integers or float it returns true. This validates that a string value contains a valid hexadecimal. This validates that a string value contains a valid hex color including hashtag (#) This validates that a string value contains a valid rgb color This validates that a string value contains a valid rgba color This validates that a string value contains a valid hsl color This validates that a string value contains a valid hsla color This validates that a string value contains a valid email This may not conform to all possibilities of any rfc standard, but neither does any email provider accept all possibilities. This validates that a string value contains a valid file path and that the file exists on the machine. This is done using os.Stat, which is a platform independent function. This validates that a string value contains a valid url This will accept any url the golang request uri accepts but must contain a schema for example http:// or rtmp:// This validates that a string value contains a valid uri This will accept any uri the golang request uri accepts This validataes that a string value contains a valid URN according to the RFC 2141 spec. This validates that a string value contains a valid base64 value. Although an empty string is valid base64 this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag. This validates that a string value contains a valid base64 URL safe value according the the RFC4648 spec. Although an empty string is a valid base64 URL safe value, this will report an empty string as an error, if you wish to accept an empty string as valid you can use this with the omitempty tag. This validates that a string value contains a valid bitcoin address. The format of the string is checked to ensure it matches one of the three formats P2PKH, P2SH and performs checksum validation. Bitcoin Bech32 Address (segwit) This validates that a string value contains a valid bitcoin Bech32 address as defined by bip-0173 (https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki) Special thanks to Pieter Wuille for providng reference implementations. This validates that a string value contains a valid ethereum address. The format of the string is checked to ensure it matches the standard Ethereum address format Full validation is blocked by https://github.com/golang/crypto/pull/28 This validates that a string value contains the substring value. This validates that a string value contains any Unicode code points in the substring value. This validates that a string value contains the supplied rune value. This validates that a string value does not contain the substring value. This validates that a string value does not contain any Unicode code points in the substring value. This validates that a string value does not contain the supplied rune value. This validates that a string value starts with the supplied string value This validates that a string value ends with the supplied string value This validates that a string value contains a valid isbn10 or isbn13 value. This validates that a string value contains a valid isbn10 value. This validates that a string value contains a valid isbn13 value. This validates that a string value contains a valid UUID. Uppercase UUID values will not pass - use `uuid_rfc4122` instead. This validates that a string value contains a valid version 3 UUID. Uppercase UUID values will not pass - use `uuid3_rfc4122` instead. This validates that a string value contains a valid version 4 UUID. Uppercase UUID values will not pass - use `uuid4_rfc4122` instead. This validates that a string value contains a valid version 5 UUID. Uppercase UUID values will not pass - use `uuid5_rfc4122` instead. This validates that a string value contains only ASCII characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains only printable ASCII characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains one or more multibyte characters. NOTE: if the string is blank, this validates as true. This validates that a string value contains a valid DataURI. NOTE: this will also validate that the data portion is valid base64 This validates that a string value contains a valid latitude. This validates that a string value contains a valid longitude. This validates that a string value contains a valid U.S. Social Security Number. This validates that a string value contains a valid IP Address. This validates that a string value contains a valid v4 IP Address. This validates that a string value contains a valid v6 IP Address. This validates that a string value contains a valid CIDR Address. This validates that a string value contains a valid v4 CIDR Address. This validates that a string value contains a valid v6 CIDR Address. This validates that a string value contains a valid resolvable TCP Address. This validates that a string value contains a valid resolvable v4 TCP Address. This validates that a string value contains a valid resolvable v6 TCP Address. This validates that a string value contains a valid resolvable UDP Address. This validates that a string value contains a valid resolvable v4 UDP Address. This validates that a string value contains a valid resolvable v6 UDP Address. This validates that a string value contains a valid resolvable IP Address. This validates that a string value contains a valid resolvable v4 IP Address. This validates that a string value contains a valid resolvable v6 IP Address. This validates that a string value contains a valid Unix Address. This validates that a string value contains a valid MAC Address. Note: See Go's ParseMAC for accepted formats and types: This validates that a string value is a valid Hostname according to RFC 952 https://tools.ietf.org/html/rfc952 This validates that a string value is a valid Hostname according to RFC 1123 https://tools.ietf.org/html/rfc1123 Full Qualified Domain Name (FQDN) This validates that a string value contains a valid FQDN. This validates that a string value appears to be an HTML element tag including those described at https://developer.mozilla.org/en-US/docs/Web/HTML/Element This validates that a string value is a proper character reference in decimal or hexadecimal format This validates that a string value is percent-encoded (URL encoded) according to https://tools.ietf.org/html/rfc3986#section-2.1 This validates that a string value contains a valid directory and that it exists on the machine. This is done using os.Stat, which is a platform independent function. NOTE: When returning an error, the tag returned in "FieldError" will be the alias tag unless the dive tag is part of the alias. Everything after the dive tag is not reported as the alias tag. Also, the "ActualTag" in the before case will be the actual tag within the alias that failed. Here is a list of the current built in alias tags: Validator notes: A collection of validation rules that are frequently needed but are more complex than the ones found in the baked in validators. A non standard validator must be registered manually like you would with your own custom validation functions. Example of registration and use: Here is a list of the current non standard validators: This package panics when bad input is provided, this is by design, bad code like that should not make it to production.
Package advancedtls provides gRPC transport credentials that allow easy configuration of advanced TLS features. The APIs here give the user more customizable control to fit their security landscape, thus the "advanced" moniker. This package provides both interfaces and generally useful implementations of those interfaces, for example periodic credential reloading, support for certificate revocation lists, and customizable certificate verification behaviors. If the provided implementations do not fit a given use case, a custom implementation of the interface can be injected.
test.go is a "Go script" for running Vitess tests. It runs each test in its own Docker container for hermeticity and (potentially) parallelism. If a test fails, this script will save the output in _test/ and continue with other tests. Before using it, you should have Docker 1.5+ installed, and have your user in the group that lets you run the docker command without sudo. The first time you run against a given flavor, it may take some time for the corresponding bootstrap image (vitess/bootstrap:<flavor>) to be downloaded. It is meant to be run from the Vitess root, like so: For a list of options, run:
Package tview implements rich widgets for terminal based user interfaces. The widgets provided with this package are useful for data exploration and data entry. The package implements the following widgets: The package also provides Application which is used to poll the event queue and draw widgets on screen. The following is a very basic example showing a box with the title "Hello, world!": First, we create a box primitive with a border and a title. Then we create an application, set the box as its root primitive, and run the event loop. The application exits when the application's Application.Stop function is called or when Ctrl-C is pressed. You will find more demos in the "demos" subdirectory. It also contains a presentation (written using tview) which gives an overview of the different widgets and how they can be used. Throughout this package, styles are specified using the tcell.Style type. Styles specify colors with the tcell.Color type. Functions such as tcell.GetColor, tcell.NewHexColor, and tcell.NewRGBColor can be used to create colors from W3C color names or RGB values. The tcell.Style type also allows you to specify text attributes such as "bold" or "underline" or a URL which some terminals use to display hyperlinks. Almost all strings which are displayed may contain style tags. A style tag's content is always wrapped in square brackets. In its simplest form, a style tag specifies the foreground color of the text. Colors in these tags are W3C color names or six hexadecimal digits following a hash tag. Examples: A style tag changes the style of the characters following that style tag. There is no style stack and no nesting of style tags. Style tags are used in almost everything from box titles, list text, form item labels, to table cells. In a TextView, this functionality has to be switched on explicitly. See the TextView documentation for more information. A style tag's full format looks like this: Each of the four fields can be left blank and trailing fields can be omitted. (Empty square brackets "[]", however, are not considered style tags.) Fields that are not specified will be left unchanged. A field with just a dash ("-") means "reset to default". You can specify the following flags to turn on certain attributes (some flags may not be supported by your terminal): Use uppercase letters to turn off the corresponding attribute, for example, "B" to turn off bold. Uppercase letters have no effect if the attribute was not previously set. Setting a URL allows you to turn a piece of text into a hyperlink in some terminals. Specify a dash ("-") to specify the end of the hyperlink. Hyperlinks must only contain single-byte characters (e.g. ASCII) and they may not contain bracket characters ("[" or "]"). Examples: In the rare event that you want to display a string such as "[red]" or "[#00ff1a]" without applying its effect, you need to put an opening square bracket before the closing square bracket. Note that the text inside the brackets will be matched less strictly than region or colors tags. I.e. any character that may be used in color or region tags will be recognized. Examples: You can use the Escape() function to insert brackets automatically where needed. When primitives are instantiated, they are initialized with colors taken from the global Styles variable. You may change this variable to adapt the look and feel of the primitives to your preferred style. Note that most terminals will not report information about their color theme. This package therefore does not support using the terminal's color theme. The default style is a dark theme and you must change the Styles variable to switch to a light (or other) theme. This package supports all unicode characters supported by your terminal. If your terminal supports mouse events, you can enable mouse support for your application by calling Application.EnableMouse. Note that this may interfere with your terminal's default mouse behavior. Mouse support is disabled by default. Many functions in this package are not thread-safe. For many applications, this is not an issue: If your code makes changes in response to key events, the corresponding callback function will execute in the main goroutine and thus will not cause any race conditions. (Exceptions to this are documented.) If you access your primitives from other goroutines, however, you will need to synchronize execution. The easiest way to do this is to call Application.QueueUpdate or Application.QueueUpdateDraw (see the function documentation for details): One exception to this is the io.Writer interface implemented by TextView. You can safely write to a TextView from any goroutine. See the TextView documentation for details. You can also call Application.Draw from any goroutine without having to wrap it in Application.QueueUpdate. And, as mentioned above, key event callbacks are executed in the main goroutine and thus should not use Application.QueueUpdate as that may lead to deadlocks. It is also not necessary to call Application.Draw from such callbacks as it will be called automatically. All widgets listed above contain the Box type. All of Box's functions are therefore available for all widgets, too. Please note that if you are using the functions of Box on a subclass, they will return a *Box, not the subclass. This is a Golang limitation. So while tview supports method chaining in many places, these chains must be broken when using Box's functions. Example: You will need to call Box.SetBorder separately: All widgets also implement the Primitive interface. The tview package's rendering is based on version 2 of https://github.com/gdamore/tcell. It uses types and constants from that package (e.g. colors, styles, and keyboard values).
Package spanner provides a client for reading and writing to Cloud Spanner databases. See the packages under admin for clients that operate on databases and instances. See https://cloud.google.com/spanner/docs/getting-started/go/ for an introduction to Cloud Spanner and additional help on using this API. See https://godoc.org/cloud.google.com/go for authentication, timeouts, connection pooling and similar aspects of this package. To start working with this package, create a client that refers to the database of interest: Remember to close the client after use to free up the sessions in the session pool. To use an emulator with this library, you can set the SPANNER_EMULATOR_HOST environment variable to the address at which your emulator is running. This will send requests to that address instead of to Cloud Spanner. You can then create and use a client as usual: Two Client methods, Apply and Single, work well for simple reads and writes. As a quick introduction, here we write a new row to the database and read it back: All the methods used above are discussed in more detail below. Every Cloud Spanner row has a unique key, composed of one or more columns. Construct keys with a literal of type Key: The keys of a Cloud Spanner table are ordered. You can specify ranges of keys using the KeyRange type: By default, a KeyRange includes its start key but not its end key. Use the Kind field to specify other boundary conditions: A KeySet represents a set of keys. A single Key or KeyRange can act as a KeySet. Use the KeySets function to build the union of several KeySets: AllKeys returns a KeySet that refers to all the keys in a table: All Cloud Spanner reads and writes occur inside transactions. There are two types of transactions, read-only and read-write. Read-only transactions cannot change the database, do not acquire locks, and may access either the current database state or states in the past. Read-write transactions can read the database before writing to it, and always apply to the most recent database state. The simplest and fastest transaction is a ReadOnlyTransaction that supports a single read operation. Use Client.Single to create such a transaction. You can chain the call to Single with a call to a Read method. When you only want one row whose key you know, use ReadRow. Provide the table name, key, and the columns you want to read: Read multiple rows with the Read method. It takes a table name, KeySet, and list of columns: Read returns a RowIterator. You can call the Do method on the iterator and pass a callback: RowIterator also follows the standard pattern for the Google Cloud Client Libraries: Always call Stop when you finish using an iterator this way, whether or not you iterate to the end. (Failing to call Stop could lead you to exhaust the database's session quota.) To read rows with an index, use ReadUsingIndex. The most general form of reading uses SQL statements. Construct a Statement with NewStatement, setting any parameters using the Statement's Params map: You can also construct a Statement directly with a struct literal, providing your own map of parameters. Use the Query method to run the statement and obtain an iterator: Once you have a Row, via an iterator or a call to ReadRow, you can extract column values in several ways. Pass in a pointer to a Go variable of the appropriate type when you extract a value. You can extract by column position or name: You can extract all the columns at once: Or you can define a Go struct that corresponds to your columns, and extract into that: For Cloud Spanner columns that may contain NULL, use one of the NullXXX types, like NullString: To perform more than one read in a transaction, use ReadOnlyTransaction: You must call Close when you are done with the transaction. Cloud Spanner read-only transactions conceptually perform all their reads at a single moment in time, called the transaction's read timestamp. Once a read has started, you can call ReadOnlyTransaction's Timestamp method to obtain the read timestamp. By default, a transaction will pick the most recent time (a time where all previously committed transactions are visible) for its reads. This provides the freshest data, but may involve some delay. You can often get a quicker response if you are willing to tolerate "stale" data. You can control the read timestamp selected by a transaction by calling the WithTimestampBound method on the transaction before using it. For example, to perform a query on data that is at most one minute stale, use See the documentation of TimestampBound for more details. To write values to a Cloud Spanner database, construct a Mutation. The spanner package has functions for inserting, updating and deleting rows. Except for the Delete methods, which take a Key or KeyRange, each mutation-building function comes in three varieties. One takes lists of columns and values along with the table name: One takes a map from column names to values: And the third accepts a struct value, and determines the columns from the struct field names: To apply a list of mutations to the database, use Apply: If you need to read before writing in a single transaction, use a ReadWriteTransaction. ReadWriteTransactions may be aborted automatically by the backend and need to be retried. You pass in a function to ReadWriteTransaction, and the client will handle the retries automatically. Use the transaction's BufferWrite method to buffer mutations, which will all be executed at the end of the transaction: Cloud Spanner STRUCT (aka STRUCT) values (https://cloud.google.com/spanner/docs/data-types#struct-type) can be represented by a Go struct value. A proto StructType is built from the field types and field tag information of the Go struct. If a field in the struct type definition has a "spanner:<field_name>" tag, then the value of the "spanner" key in the tag is used as the name for that field in the built StructType, otherwise the field name in the struct definition is used. To specify a field with an empty field name in a Cloud Spanner STRUCT type, use the `spanner:""` tag annotation against the corresponding field in the Go struct's type definition. A STRUCT value can contain STRUCT-typed and Array-of-STRUCT typed fields and these can be specified using named struct-typed and []struct-typed fields inside a Go struct. However, embedded struct fields are not allowed. Unexported struct fields are ignored. NULL STRUCT values in Cloud Spanner are typed. A nil pointer to a Go struct value can be used to specify a NULL STRUCT value of the corresponding StructType. Nil and empty slices of a Go STRUCT type can be used to specify NULL and empty array values respectively of the corresponding StructType. A slice of pointers to a Go struct type can be used to specify an array of NULL-able STRUCT values. Spanner supports DML statements like INSERT, UPDATE and DELETE. Use ReadWriteTransaction.Update to run DML statements. It returns the number of rows affected. (You can call use ReadWriteTransaction.Query with a DML statement. The first call to Next on the resulting RowIterator will return iterator.Done, and the RowCount field of the iterator will hold the number of affected rows.) For large databases, it may be more efficient to partition the DML statement. Use client.PartitionedUpdate to run a DML statement in this way. Not all DML statements can be partitioned. This client has been instrumented to use OpenCensus tracing (http://opencensus.io). To enable tracing, see "Enabling Tracing for a Program" at https://godoc.org/go.opencensus.io/trace. OpenCensus tracing requires Go 1.8 or higher.
Package wishlist provides a library and binary to list and connect to SSH apps.
Package age implements file encryption according to the age-encryption.org/v1 specification. For most use cases, use the Encrypt and Decrypt functions with X25519Recipient and X25519Identity. If passphrase encryption is required, use ScryptRecipient and ScryptIdentity. For compatibility with existing SSH keys use the filippo.io/age/agessh package. age encrypted files are binary and not malleable. For encoding them as text, use the filippo.io/age/armor package. age does not have a global keyring. Instead, since age keys are small, textual, and cheap, you are encouraged to generate dedicated keys for each task and application. Recipient public keys can be passed around as command line flags and in config files, while secret keys should be stored in dedicated files, through secret management systems, or as environment variables. There is no default path for age keys. Instead, they should be stored at application-specific paths. The CLI supports files where private keys are listed one per line, ignoring empty lines and lines starting with "#". These files can be parsed with ParseIdentities. When integrating age into a new system, it's recommended that you only support X25519 keys, and not SSH keys. The latter are supported for manual encryption operations. If you need to tie into existing key management infrastructure, you might want to consider implementing your own Recipient and Identity. Files encrypted with a stable version (not alpha, beta, or release candidate) of age, or with any v1.0.0 beta or release candidate, will decrypt with any later versions of the v1 API. This might change in v2, in which case v1 will be maintained with security fixes for compatibility with older files. If decrypting an older file poses a security risk, doing so might require an explicit opt-in in the API.
Package gomail provides a simple interface to compose emails and to mail them efficiently. More info on Github: https://github.com/go-gomail/gomail A daemon that listens to a channel and sends all incoming messages. Efficiently send a customized newsletter to a list of recipients. Send an email using a local SMTP server. Send an email using an API or postfix.