HTTP

Package httpproxy provides a customizable HTTP proxy; supports HTTP, HTTPS through CONNECT. And also provides HTTPS connection using "Man in the Middle" style attack. It's easy to use. `httpproxy.Proxy` implements `Handler` interface of `net/http` package to offer `http.ListenAndServe` function.

Package gorilla/http is a high level HTTP client. This package provides high level convience methods for common http operations. Additionally a high level HTTP client implementation. These high level functions are expected to change. Your feedback on their form and utility is warmly requested. Please raise issues at https://github.com/gorilla/http/issues. For lower level http implementations, see gorilla/http/client.

Package fasthttp provides fast HTTP server and client API. Fasthttp provides the following features: Optimized for speed. Easily handles more than 100K qps and more than 1M concurrent keep-alive connections on modern hardware. Optimized for low memory usage. Easy 'Connection: Upgrade' support via RequestCtx.Hijack. Server supports requests' pipelining. Multiple requests may be read from a single network packet and multiple responses may be sent in a single network packet. This may be useful for highly loaded REST services. Server provides the following anti-DoS limits: The number of concurrent connections. The number of concurrent connections per client IP. The number of requests per connection. Request read timeout. Response write timeout. Maximum request header size. Maximum request body size. Maximum request execution time. Maximum keep-alive connection lifetime. Early filtering out non-GET requests. A lot of additional useful info is exposed to request handler: Server and client address. Per-request logger. Unique request id. Request start time. Connection start time. Request sequence number for the current connection. Client supports automatic retry on idempotent requests' failure. Fasthttp API is designed with the ability to extend existing client and server implementations or to write custom client and server implementations from scratch.

Package http implements a go-micro.Server

httpsignatures is a golang implementation of the http-signatures spec found at https://tools.ietf.org/html/draft-cavage-http-signatures

Package httpbin providers HTTP handlers for httpbin.org endpoints and a multiplexer to directly hook it up to any http.Server or httptest.Server.

Package http_dialer provides HTTP(S) CONNECT tunneling net.Dialer. It allows you to establish arbitrary TCP connections (as long as your proxy allows them) through a HTTP(S) CONNECT point.

Package httpgzip provides net/http-like primitives that use gzip compression when serving HTTP requests.

Implements HTTP request and response signing and verification. Supports the major MAC and asymmetric key signature algorithms. It has several safety restrictions: One, none of the widely known non-cryptographically safe algorithms are permitted; Two, the RSA SHA256 algorithms must be available in the binary (and it should, barring export restrictions); Finally, the library assumes either the 'Authorizationn' or 'Signature' headers are to be set (but not both).

Package oauth2 provides support for making OAuth2 authorized and authenticated HTTP requests, as specified in RFC 6749. It can additionally grant authorization with Bearer JWT. Copyright 2023 The Go Authors. All rights reserved. Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.

Package gin implements a HTTP web framework called gin. See https://gin-gonic.com/ for more information about gin.

Package websocket implements the WebSocket protocol defined in RFC 6455. The Conn type represents a WebSocket connection. A server application calls the Upgrader.Upgrade method from an HTTP request handler to get a *Conn: Call the connection's WriteMessage and ReadMessage methods to send and receive messages as a slice of bytes. This snippet of code shows how to echo messages using these methods: In above snippet of code, p is a []byte and messageType is an int with value websocket.BinaryMessage or websocket.TextMessage. An application can also send and receive messages using the io.WriteCloser and io.Reader interfaces. To send a message, call the connection NextWriter method to get an io.WriteCloser, write the message to the writer and close the writer when done. To receive a message, call the connection NextReader method to get an io.Reader and read until io.EOF is returned. This snippet shows how to echo messages using the NextWriter and NextReader methods: The WebSocket protocol distinguishes between text and binary data messages. Text messages are interpreted as UTF-8 encoded text. The interpretation of binary messages is left to the application. This package uses the TextMessage and BinaryMessage integer constants to identify the two data message types. The ReadMessage and NextReader methods return the type of the received message. The messageType argument to the WriteMessage and NextWriter methods specifies the type of a sent message. It is the application's responsibility to ensure that text messages are valid UTF-8 encoded text. The WebSocket protocol defines three types of control messages: close, ping and pong. Call the connection WriteControl, WriteMessage or NextWriter methods to send a control message to the peer. Connections handle received close messages by calling the handler function set with the SetCloseHandler method and by returning a *CloseError from the NextReader, ReadMessage or the message Read method. The default close handler sends a close message to the peer. Connections handle received ping messages by calling the handler function set with the SetPingHandler method. The default ping handler sends a pong message to the peer. Connections handle received pong messages by calling the handler function set with the SetPongHandler method. The default pong handler does nothing. If an application sends ping messages, then the application should set a pong handler to receive the corresponding pong. The control message handler functions are called from the NextReader, ReadMessage and message reader Read methods. The default close and ping handlers can block these methods for a short time when the handler writes to the connection. The application must read the connection to process close, ping and pong messages sent from the peer. If the application is not otherwise interested in messages from the peer, then the application should start a goroutine to read and discard messages from the peer. A simple example is: Connections support one concurrent reader and one concurrent writer. Applications are responsible for ensuring that no more than one goroutine calls the write methods (NextWriter, SetWriteDeadline, WriteMessage, WriteJSON, EnableWriteCompression, SetCompressionLevel) concurrently and that no more than one goroutine calls the read methods (NextReader, SetReadDeadline, ReadMessage, ReadJSON, SetPongHandler, SetPingHandler) concurrently. The Close and WriteControl methods can be called concurrently with all other methods. Web browsers allow Javascript applications to open a WebSocket connection to any host. It's up to the server to enforce an origin policy using the Origin request header sent by the browser. The Upgrader calls the function specified in the CheckOrigin field to check the origin. If the CheckOrigin function returns false, then the Upgrade method fails the WebSocket handshake with HTTP status 403. If the CheckOrigin field is nil, then the Upgrader uses a safe default: fail the handshake if the Origin request header is present and the Origin host is not equal to the Host request header. The deprecated package-level Upgrade function does not perform origin checking. The application is responsible for checking the Origin header before calling the Upgrade function. Connections buffer network input and output to reduce the number of system calls when reading or writing messages. Write buffers are also used for constructing WebSocket frames. See RFC 6455, Section 5 for a discussion of message framing. A WebSocket frame header is written to the network each time a write buffer is flushed to the network. Decreasing the size of the write buffer can increase the amount of framing overhead on the connection. The buffer sizes in bytes are specified by the ReadBufferSize and WriteBufferSize fields in the Dialer and Upgrader. The Dialer uses a default size of 4096 when a buffer size field is set to zero. The Upgrader reuses buffers created by the HTTP server when a buffer size field is set to zero. The HTTP server buffers have a size of 4096 at the time of this writing. The buffer sizes do not limit the size of a message that can be read or written by a connection. Buffers are held for the lifetime of the connection by default. If the Dialer or Upgrader WriteBufferPool field is set, then a connection holds the write buffer only when writing a message. Applications should tune the buffer sizes to balance memory use and performance. Increasing the buffer size uses more memory, but can reduce the number of system calls to read or write the network. In the case of writing, increasing the buffer size can reduce the number of frame headers written to the network. Some guidelines for setting buffer parameters are: Limit the buffer sizes to the maximum expected message size. Buffers larger than the largest message do not provide any benefit. Depending on the distribution of message sizes, setting the buffer size to a value less than the maximum expected message size can greatly reduce memory use with a small impact on performance. Here's an example: If 99% of the messages are smaller than 256 bytes and the maximum message size is 512 bytes, then a buffer size of 256 bytes will result in 1.01 more system calls than a buffer size of 512 bytes. The memory savings is 50%. A write buffer pool is useful when the application has a modest number writes over a large number of connections. when buffers are pooled, a larger buffer size has a reduced impact on total memory use and has the benefit of reducing system calls and frame overhead. Per message compression extensions (RFC 7692) are experimentally supported by this package in a limited capacity. Setting the EnableCompression option to true in Dialer or Upgrader will attempt to negotiate per message deflate support. If compression was successfully negotiated with the connection's peer, any message received in compressed form will be automatically decompressed. All Read methods will return uncompressed bytes. Per message compression of messages written to a connection can be enabled or disabled by calling the corresponding Conn method: Currently this package does not support compression with "context takeover". This means that messages must be compressed and decompressed in isolation, without retaining sliding window or dictionary state across messages. For more details refer to RFC 7692. Use of compression is experimental and may result in decreased performance.

`httpwares` is a collection of middlewares (server-side) and tripperwares (client-side) for vanilla Golang HTTP libs

Package influxdb is the root package of InfluxDB, the scalable datastore for metrics, events, and real-time analytics. If you're looking for the Go HTTP client for InfluxDB, see package github.com/influxdata/influxdb/client/v2.

Package p2phttp allows to serve HTTP endpoints and make HTTP requests through LibP2P (https://github.com/libp2p/libp2p) using Go's standard "http" and "net" stacks. Instead of the regular "host:port" addressing, `p2phttp` uses a Peer ID and lets LibP2P take care of the routing, thus taking advantage of features like multi-routes, NAT transversal and stream multiplexing over a single connection. When already running a LibP2P facility, this package allows to expose existing HTTP-based services (like REST APIs) through LibP2P and to use those services with minimal changes to the code-base. For example, a simple http.Server on LibP2P works as: As shown above, a Server only needs a "github.com/libp2p/go-libp2p-gostream" listener. This listener will use a libP2P host to watch for stream tagged with our Protocol. On the other side, a client just needs to be initialized with a custom LibP2P host-based transport to perform requests to such server: In the example above, the client registers a "libp2p" protocol for which the custom transport is used. It can still perform regular "http" requests. The protocol name used is arbitraty and non standard. Note that LibP2P hosts cannot dial to themselves, so there is no possibility of using the same host as server and as client.

Package httphealth provides a simple component that offers an http interface for health checking and monitoring using Prometheus. This package is a work in progress and makes no API stability promises.

Package micro is a pluggable framework for microservices

Package micro is a pluggable framework for microservices

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 httpserver provides functions that are useful for HTTP servers. These functions are meant to be used primarily in tests. Provides functions for determining an available port and checking to see when a server is "ready" based on the response provided by an endpoint.

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 fiber is an Express inspired web framework built on top of Fasthttp, the fastest HTTP engine for Go. Designed to ease things up for fast development with zero memory allocation and performance in mind.

Package gin implements a HTTP web framework called gin. See https://gin-gonic.github.io/gin/ for more information about gin.

Package chi is a small, idiomatic and composable router for building HTTP services. chi requires Go 1.10 or newer. Example: See github.com/go-chi/chi/_examples/ for more in-depth examples. URL patterns allow for easy matching of path components in HTTP requests. The matching components can then be accessed using chi.URLParam(). All patterns must begin with a slash. A simple named placeholder {name} matches any sequence of characters up to the next / or the end of the URL. Trailing slashes on paths must be handled explicitly. A placeholder with a name followed by a colon allows a regular expression match, for example {number:\\d+}. The regular expression syntax is Go's normal regexp RE2 syntax, except that regular expressions including { or } are not supported, and / will never be matched. An anonymous regexp pattern is allowed, using an empty string before the colon in the placeholder, such as {:\\d+} The special placeholder of asterisk matches the rest of the requested URL. Any trailing characters in the pattern are ignored. This is the only placeholder which will match / characters. Examples:

Package http provides a http client

Package chi is a small, idiomatic and composable router for building HTTP services. chi requires Go 1.14 or newer. Example: See github.com/go-chi/chi/_examples/ for more in-depth examples. URL patterns allow for easy matching of path components in HTTP requests. The matching components can then be accessed using chi.URLParam(). All patterns must begin with a slash. A simple named placeholder {name} matches any sequence of characters up to the next / or the end of the URL. Trailing slashes on paths must be handled explicitly. A placeholder with a name followed by a colon allows a regular expression match, for example {number:\\d+}. The regular expression syntax is Go's normal regexp RE2 syntax, except that regular expressions including { or } are not supported, and / will never be matched. An anonymous regexp pattern is allowed, using an empty string before the colon in the placeholder, such as {:\\d+} The special placeholder of asterisk matches the rest of the requested URL. Any trailing characters in the pattern are ignored. This is the only placeholder which will match / characters. Examples:

Package httpsfv implements serializing and parsing of Structured Field Values for HTTP as defined in RFC 9651. Structured Field Values are either lists, dictionaries or items. Dedicated types are provided for all of them. Dedicated types are also used for tokens, parameters and inner lists. Other values are stored in native types: The specification is available at https://httpwg.org/specs/rfc9651.html.

Taken from $GOROOT/src/pkg/net/http/chunked needed to write https responses to client. Package goproxy provides a customizable HTTP proxy, supporting hijacking HTTPS connection. The intent of the proxy, is to be usable with reasonable amount of traffic yet, customizable and programmable. The proxy itself is simply an `net/http` handler. Typical usage is Adding a header to each request > Note that the function is called before the proxy sends the request to the server For printing the content type of all incoming responses note that we used the ProxyCtx context variable here. It contains the request and the response (Req and Resp, Resp is nil if unavailable) of this specific client interaction with the proxy. To print the content type of all responses from a certain url, we'll add a ReqCondition to the OnResponse function: We can write the condition ourselves, conditions can be set on request and on response Caution! If you give a RespCondition to the OnRequest function, you'll get a run time panic! It doesn't make sense to read the response, if you still haven't got it! Finally, we have convenience function to throw a quick response we close the body of the original response, and return a new 403 response with a short message. Example use cases: 1. https://github.com/elazarl/goproxy/tree/master/examples/goproxy-avgsize To measure the average size of an Html served in your site. One can ask all the QA team to access the website by a proxy, and the proxy will measure the average size of all text/html responses from your host. 2. [not yet implemented] All requests to your web servers should be directed through the proxy, when the proxy will detect html pieces sent as a response to AJAX request, it'll send a warning email. 3. https://github.com/elazarl/goproxy/blob/master/examples/goproxy-httpdump/ Generate a real traffic to your website by real users using through proxy. Record the traffic, and try it again for more real load testing. 4. https://github.com/elazarl/goproxy/tree/master/examples/goproxy-no-reddit-at-worktime Will allow browsing to reddit.com between 8:00am and 17:00pm 5. https://github.com/elazarl/goproxy/tree/master/examples/goproxy-jquery-version Will warn if multiple versions of jquery are used in the same domain. 6. https://github.com/elazarl/goproxy/blob/master/examples/goproxy-upside-down-ternet/ Modifies image files in an HTTP response via goproxy's image extension found in ext/.

Package cloud is the root of the packages used to access Google Cloud Services. See https://pkg.go.dev/cloud.google.com/go#section-directories 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: 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 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 google.golang.org/api/option.WithGRPCConnectionPool 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. 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: