http

Documentation

Index

• Constants
• func DefaultErrorEncoder(_ context.Context, err error, w http.ResponseWriter)
• func EncodeJSONResponse(_ context.Context, w http.ResponseWriter, response interface{}) error
• func PopulateRequestContext(ctx context.Context, r *http.Request) context.Context
• type ClientResponseFunc
• type CreateRequestFunc
• type DecodeRequestFunc
• type DecodeResponseFunc
• type EncodeRequestFunc
• type EncodeResponseFunc
• type ErrorEncoder
• type Headerer
• type RequestFunc
  • func SetRequestHeader(key, val string) RequestFunc
• type Server
  • func NewServer(e endpoint.Endpoint, dec DecodeRequestFunc, enc EncodeResponseFunc, ...) *Server
  • func (s Server) ServeHTTP(w http.ResponseWriter, r *http.Request)
• type ServerOption
  • func ServerAfter(after ...ServerResponseFunc) ServerOption
  • func ServerBefore(before ...RequestFunc) ServerOption
  • func ServerErrorEncoder(ee ErrorEncoder) ServerOption
  • func ServerErrorLogger(logger *slog.Logger) ServerOption
• type ServerResponseFunc
  • func SetContentType(contentType string) ServerResponseFunc
  • func SetResponseHeader(key, val string) ServerResponseFunc
• type StatusCoder

Constants

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
)

Functions

func DefaultErrorEncoder

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 EncodeJSONResponse

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 PopulateRequestContext

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.

Types

type ClientResponseFunc

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 CreateRequestFunc

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

CreateRequestFunc creates an outgoing HTTP request based on the passed request object. It's designed to be used in HTTP clients, for client-side endpoints. It's a more powerful version of EncodeRequestFunc, and can be used if more fine-grained control of the HTTP request is required.

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 request 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 be 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

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 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 *slog.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.

type ServerResponseFunc

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

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.