http

package
v0.6.0 Latest Latest
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 Go to latest Published: Oct 3, 2017 License: MIT Imports: 9 Imported by: 4,842

Documentation

Overview

Package http provides a general purpose HTTP binding for endpoints.

Index

Examples

Constants

View Source 
const (
	// ContextKeyRequestMethod is populated in the context by
	// PopulateRequestContext. Its value is r.Method.
	ContextKeyRequestMethod contextKey = iota

	// ContextKeyRequestURI is populated in the context by
	// PopulateRequestContext. Its value is r.RequestURI.
	ContextKeyRequestURI

	// ContextKeyRequestPath is populated in the context by
	// PopulateRequestContext. Its value is r.URL.Path.
	ContextKeyRequestPath

	// ContextKeyRequestProto is populated in the context by
	// PopulateRequestContext. Its value is r.Proto.
	ContextKeyRequestProto

	// ContextKeyRequestHost is populated in the context by
	// PopulateRequestContext. Its value is r.Host.
	ContextKeyRequestHost

	// ContextKeyRequestRemoteAddr is populated in the context by
	// PopulateRequestContext. Its value is r.RemoteAddr.
	ContextKeyRequestRemoteAddr

	// ContextKeyRequestXForwardedFor is populated in the context by
	// PopulateRequestContext. Its value is r.Header.Get("X-Forwarded-For").
	ContextKeyRequestXForwardedFor

	// ContextKeyRequestXForwardedProto is populated in the context by
	// PopulateRequestContext. Its value is r.Header.Get("X-Forwarded-Proto").
	ContextKeyRequestXForwardedProto

	// ContextKeyRequestAuthorization is populated in the context by
	// PopulateRequestContext. Its value is r.Header.Get("Authorization").
	ContextKeyRequestAuthorization

	// ContextKeyRequestReferer is populated in the context by
	// PopulateRequestContext. Its value is r.Header.Get("Referer").
	ContextKeyRequestReferer

	// ContextKeyRequestUserAgent is populated in the context by
	// PopulateRequestContext. Its value is r.Header.Get("User-Agent").
	ContextKeyRequestUserAgent

	// ContextKeyRequestXRequestID is populated in the context by
	// PopulateRequestContext. Its value is r.Header.Get("X-Request-Id").
	ContextKeyRequestXRequestID

	// ContextKeyRequestAccept is populated in the context by
	// PopulateRequestContext. Its value is r.Header.Get("Accept").
	ContextKeyRequestAccept

	// ContextKeyResponseHeaders is populated in the context whenever a
	// ServerFinalizerFunc is specified. Its value is of type http.Header, and
	// is captured only once the entire response has been written.
	ContextKeyResponseHeaders

	// ContextKeyResponseSize is populated in the context whenever a
	// ServerFinalizerFunc is specified. Its value is of type int64.
	ContextKeyResponseSize
)

Variables

This section is empty.

Functions

func DefaultErrorEncoder added in v0.4.0 

func DefaultErrorEncoder(_ context.Context, err error, w http.ResponseWriter)

DefaultErrorEncoder writes the error to the ResponseWriter, by default a content type of text/plain, a body of the plain text of the error, and a status code of 500. If the error implements Headerer, the provided headers will be applied to the response. If the error implements json.Marshaler, and the marshaling succeeds, a content type of application/json and the JSON encoded form of the error will be used. If the error implements StatusCoder, the provided StatusCode will be used instead of 500.

func EncodeJSONRequest added in v0.4.0 

func EncodeJSONRequest(c context.Context, r *http.Request, request interface{}) error

EncodeJSONRequest is an EncodeRequestFunc that serializes the request as a JSON object to the Request body. Many JSON-over-HTTP services can use it as a sensible default. If the request implements Headerer, the provided headers will be applied to the request.

func EncodeJSONResponse added in v0.4.0 

func EncodeJSONResponse(_ context.Context, w http.ResponseWriter, response interface{}) error

EncodeJSONResponse is a EncodeResponseFunc that serializes the response as a JSON object to the ResponseWriter. Many JSON-over-HTTP services can use it as a sensible default. If the response implements Headerer, the provided headers will be applied to the response. If the response implements StatusCoder, the provided StatusCode will be used instead of 200.

func EncodeXMLRequest added in v0.4.0 

func EncodeXMLRequest(c context.Context, r *http.Request, request interface{}) error

EncodeXMLRequest is an EncodeRequestFunc that serializes the request as a XML object to the Request body. If the request implements Headerer, the provided headers will be applied to the request.

func PopulateRequestContext added in v0.4.0 

func PopulateRequestContext(ctx context.Context, r *http.Request) context.Context

PopulateRequestContext is a RequestFunc that populates several values into the context from the HTTP request. Those values may be extracted using the corresponding ContextKey type in this package.

Example 
handler := NewServer(
	func(ctx context.Context, request interface{}) (response interface{}, err error) {
		fmt.Println("Method", ctx.Value(ContextKeyRequestMethod).(string))
		fmt.Println("RequestPath", ctx.Value(ContextKeyRequestPath).(string))
		fmt.Println("RequestURI", ctx.Value(ContextKeyRequestURI).(string))
		fmt.Println("X-Request-ID", ctx.Value(ContextKeyRequestXRequestID).(string))
		return struct{}{}, nil
	},
	func(context.Context, *http.Request) (interface{}, error) { return struct{}{}, nil },
	func(context.Context, http.ResponseWriter, interface{}) error { return nil },
	ServerBefore(PopulateRequestContext),
)

server := httptest.NewServer(handler)
defer server.Close()

req, _ := http.NewRequest("PATCH", fmt.Sprintf("%s/search?q=sympatico", server.URL), nil)
req.Header.Set("X-Request-Id", "a1b2c3d4e5")
http.DefaultClient.Do(req)

Output:

Method PATCH
RequestPath /search
RequestURI /search?q=sympatico
X-Request-ID a1b2c3d4e5

Types

type Client 

type Client struct {
	// contains filtered or unexported fields
}

Client wraps a URL and provides a method that implements endpoint.Endpoint.

func NewClient 

func NewClient(
	method string,
	tgt *url.URL,
	enc EncodeRequestFunc,
	dec DecodeResponseFunc,
	options ...ClientOption,
) *Client

NewClient constructs a usable Client for a single remote method.

func (Client) Endpoint 

func (c Client) Endpoint() endpoint.Endpoint

Endpoint returns a usable endpoint that invokes the remote endpoint.

type ClientFinalizerFunc added in v0.5.0 

type ClientFinalizerFunc func(ctx context.Context, err error)

ClientFinalizerFunc can be used to perform work at the end of a client HTTP request, after the response is returned. The principal intended use is for error logging. Additional response parameters are provided in the context under keys with the ContextKeyResponse prefix. Note: err may be nil. There maybe also no additional response parameters depending on when an error occurs.

type ClientOption 

type ClientOption func(*Client)

ClientOption sets an optional parameter for clients.

func BufferedStream added in v0.2.0 

func BufferedStream(buffered bool) ClientOption

BufferedStream sets whether the Response.Body is left open, allowing it to be read from later. Useful for transporting a file as a buffered stream.

func ClientAfter added in v0.2.0 

func ClientAfter(after ...ClientResponseFunc) ClientOption

ClientAfter sets the ClientResponseFuncs applied to the incoming HTTP request prior to it being decoded. This is useful for obtaining anything off of the response and adding onto the context prior to decoding.

func ClientBefore added in v0.2.0 

func ClientBefore(before ...RequestFunc) ClientOption

ClientBefore sets the RequestFuncs that are applied to the outgoing HTTP request before it's invoked.

func ClientFinalizer added in v0.5.0 

func ClientFinalizer(f ClientFinalizerFunc) ClientOption

ClientFinalizer is executed at the end of every HTTP request. By default, no finalizer is registered.

func SetClient 

func SetClient(client *http.Client) ClientOption

SetClient sets the underlying HTTP client used for requests. By default, http.DefaultClient is used.

type ClientResponseFunc added in v0.2.0 

type ClientResponseFunc func(context.Context, *http.Response) context.Context

ClientResponseFunc may take information from an HTTP request and make the response available for consumption. ClientResponseFuncs are only executed in clients, after a request has been made, but prior to it being decoded.

type DecodeRequestFunc 

type DecodeRequestFunc func(context.Context, *http.Request) (request interface{}, err error)

DecodeRequestFunc extracts a user-domain request object from an HTTP request object. It's designed to be used in HTTP servers, for server-side endpoints. One straightforward DecodeRequestFunc could be something that JSON decodes from the request body to the concrete response type.

type DecodeResponseFunc 

type DecodeResponseFunc func(context.Context, *http.Response) (response interface{}, err error)

DecodeResponseFunc extracts a user-domain response object from an HTTP response object. It's designed to be used in HTTP clients, for client-side endpoints. One straightforward DecodeResponseFunc could be something that JSON decodes from the response body to the concrete response type.

type EncodeRequestFunc 

type EncodeRequestFunc func(context.Context, *http.Request, interface{}) error

EncodeRequestFunc encodes the passed request object into the HTTP request object. It's designed to be used in HTTP clients, for client-side endpoints. One straightforward EncodeRequestFunc could something that JSON encodes the object directly to the request body.

type EncodeResponseFunc 

type EncodeResponseFunc func(context.Context, http.ResponseWriter, interface{}) error

EncodeResponseFunc encodes the passed response object to the HTTP response writer. It's designed to be used in HTTP servers, for server-side endpoints. One straightforward EncodeResponseFunc could be something that JSON encodes the object directly to the response body.

type ErrorEncoder 

type ErrorEncoder func(ctx context.Context, err error, w http.ResponseWriter)

ErrorEncoder is responsible for encoding an error to the ResponseWriter. Users are encouraged to use custom ErrorEncoders to encode HTTP errors to their clients, and will likely want to pass and check for their own error types. See the example shipping/handling service.

type Headerer added in v0.4.0 

type Headerer interface {
	Headers() http.Header
}

Headerer is checked by DefaultErrorEncoder. If an error value implements Headerer, the provided headers will be applied to the response writer, after the Content-Type is set.

type RequestFunc 

type RequestFunc func(context.Context, *http.Request) context.Context

RequestFunc may take information from an HTTP request and put it into a request context. In Servers, RequestFuncs are executed prior to invoking the endpoint. In Clients, RequestFuncs are executed after creating the request but prior to invoking the HTTP client.

func SetRequestHeader 

func SetRequestHeader(key, val string) RequestFunc

SetRequestHeader returns a RequestFunc that sets the given header.

type Server 

type Server struct {
	// contains filtered or unexported fields
}

Server wraps an endpoint and implements http.Handler.

func NewServer 

func NewServer(
	e endpoint.Endpoint,
	dec DecodeRequestFunc,
	enc EncodeResponseFunc,
	options ...ServerOption,
) *Server

NewServer constructs a new server, which implements http.Handler and wraps the provided endpoint.

func (Server) ServeHTTP 

func (s Server) ServeHTTP(w http.ResponseWriter, r *http.Request)

ServeHTTP implements http.Handler.

type ServerFinalizerFunc added in v0.4.0 

type ServerFinalizerFunc func(ctx context.Context, code int, r *http.Request)

ServerFinalizerFunc can be used to perform work at the end of an HTTP request, after the response has been written to the client. The principal intended use is for request logging. In addition to the response code provided in the function signature, additional response parameters are provided in the context under keys with the ContextKeyResponse prefix.

type ServerOption 

type ServerOption func(*Server)

ServerOption sets an optional parameter for servers.

func ServerAfter 

func ServerAfter(after ...ServerResponseFunc) ServerOption

ServerAfter functions are executed on the HTTP response writer after the endpoint is invoked, but before anything is written to the client.

func ServerBefore 

func ServerBefore(before ...RequestFunc) ServerOption

ServerBefore functions are executed on the HTTP request object before the request is decoded.

func ServerErrorEncoder 

func ServerErrorEncoder(ee ErrorEncoder) ServerOption

ServerErrorEncoder is used to encode errors to the http.ResponseWriter whenever they're encountered in the processing of a request. Clients can use this to provide custom error formatting and response codes. By default, errors will be written with the DefaultErrorEncoder.

func ServerErrorLogger 

func ServerErrorLogger(logger log.Logger) ServerOption

ServerErrorLogger is used to log non-terminal errors. By default, no errors are logged. This is intended as a diagnostic measure. Finer-grained control of error handling, including logging in more detail, should be performed in a custom ServerErrorEncoder or ServerFinalizer, both of which have access to the context.

func ServerFinalizer added in v0.4.0 

func ServerFinalizer(f ServerFinalizerFunc) ServerOption

ServerFinalizer is executed at the end of every HTTP request. By default, no finalizer is registered.

type ServerResponseFunc added in v0.2.0 

type ServerResponseFunc func(context.Context, http.ResponseWriter) context.Context

ServerResponseFunc may take information from a request context and use it to manipulate a ResponseWriter. ServerResponseFuncs are only executed in servers, after invoking the endpoint but prior to writing a response.

func SetContentType 

func SetContentType(contentType string) ServerResponseFunc

SetContentType returns a ServerResponseFunc that sets the Content-Type header to the provided value.

func SetResponseHeader 

func SetResponseHeader(key, val string) ServerResponseFunc

SetResponseHeader returns a ServerResponseFunc that sets the given header.

type StatusCoder added in v0.4.0 

type StatusCoder interface {
	StatusCode() int
}

StatusCoder is checked by DefaultErrorEncoder. If an error value implements StatusCoder, the StatusCode will be used when encoding the error. By default, StatusInternalServerError (500) is used.

Source Files

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