const (// HTTPMethodOverrideHeader is a commonly used// http header to override a request method.HTTPMethodOverrideHeader = "X-HTTP-Method-Override"// HTTPMethodOverrideFormKey is a commonly used// HTML form key to override a request method.HTTPMethodOverrideFormKey = "_method")

funcCORS¶

func CORS(opts ...CORSOption) func(http.Handler)http.Handler

CORS provides Cross-Origin Resource Sharing middleware.Example:

import (    "net/http"    "github.com/gorilla/handlers"    "github.com/gorilla/mux")func main() {    r := mux.NewRouter()    r.HandleFunc("/users", UserEndpoint)    r.HandleFunc("/projects", ProjectEndpoint)    // Apply the CORS middleware to our top-level router, with the defaults.    http.ListenAndServe(":8000", handlers.CORS()(r))}

funcCanonicalHost¶

func CanonicalHost(domainstring, codeint) func(hhttp.Handler)http.Handler

CanonicalHost is HTTP middleware that re-directs requests to the canonicaldomain. It accepts a domain and a status code (e.g. 301 or 302) andre-directs clients to this domain. The existing request path is maintained.

Note: If the provided domain is considered invalid by url.Parse or otherwisereturns an empty scheme or host, clients are not re-directed.

Example:

r := mux.NewRouter()canonical := handlers.CanonicalHost("http://www.gorillatoolkit.org", 302)r.HandleFunc("/route", YourHandler)log.Fatal(http.ListenAndServe(":7000", canonical(r)))

funcCombinedLoggingHandler¶

func CombinedLoggingHandler(outio.Writer, hhttp.Handler)http.Handler

CombinedLoggingHandler return a http.Handler that wraps h and logs requests to out inApache Combined Log Format.

Seehttp://httpd.apache.org/docs/2.2/logs.html#combined for a description of this format.

LoggingHandler always sets the ident field of the log to -.

funcCompressHandler¶

func CompressHandler(hhttp.Handler)http.Handler

CompressHandler gzip compresses HTTP responses for clients that support itvia the 'Accept-Encoding' header.

Compressing TLS traffic may leak the page contents to an attacker if thepage contains user input:http://security.stackexchange.com/a/102015/12208

funcCompressHandlerLevel¶

func CompressHandlerLevel(hhttp.Handler, levelint)http.Handler

CompressHandlerLevel gzip compresses HTTP responses with specified compression levelfor clients that support it via the 'Accept-Encoding' header.

The compression level should be gzip.DefaultCompression, gzip.NoCompression,or any integer value between gzip.BestSpeed and gzip.BestCompression inclusive.gzip.DefaultCompression is used in case of invalid compression level.

funcContentTypeHandler¶

func ContentTypeHandler(hhttp.Handler, contentTypes ...string)http.Handler

ContentTypeHandler wraps and returns a http.Handler, validating the requestcontent type is compatible with the contentTypes list. It writes a HTTP 415error if that fails.

Only PUT, POST, and PATCH requests are considered.

funcCustomLoggingHandler¶added inv1.4.0

func CustomLoggingHandler(outio.Writer, hhttp.Handler, fLogFormatter)http.Handler

CustomLoggingHandler provides a way to supply a custom log formatterwhile taking advantage of the mechanisms in this package.

funcHTTPMethodOverrideHandler¶

func HTTPMethodOverrideHandler(hhttp.Handler)http.Handler

HTTPMethodOverrideHandler wraps and returns a http.Handler which checks forthe X-HTTP-Method-Override header or the _method form key, and overrides (ifvalid) request.Method with its value.

This is especially useful for HTTP clients that don't support many http verbs.It isn't secure to override e.g a GET to a POST, so only POST requests areconsidered. Likewise, the override method can only be a "write" method: PUT,PATCH or DELETE.

Form method takes precedence over header method.

funcLoggingHandler¶

func LoggingHandler(outio.Writer, hhttp.Handler)http.Handler

LoggingHandler return a http.Handler that wraps h and logs requests to out inApache Common Log Format (CLF).

Seehttp://httpd.apache.org/docs/2.2/logs.html#common for a description of this format.

LoggingHandler always sets the ident field of the log to -

Example:

r := mux.NewRouter()r.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {w.Write([]byte("This is a catch-all route"))})loggedRouter := handlers.LoggingHandler(os.Stdout, r)http.ListenAndServe(":1123", loggedRouter)

funcProxyHeaders¶

func ProxyHeaders(hhttp.Handler)http.Handler

ProxyHeaders inspects common reverse proxy headers and sets the correspondingfields in the HTTP request struct. These are X-Forwarded-For and X-Real-IPfor the remote (client) IP address, X-Forwarded-Proto or X-Forwarded-Schemefor the scheme (http|https), X-Forwarded-Host for the host and the RFC7239Forwarded header, which may include both client IPs and schemes.

NOTE: This middleware should only be used when behind a reverseproxy like nginx, HAProxy or Apache. Reverse proxies that don't (or areconfigured not to) strip these headers from client requests, or where theseheaders are accepted "as is" from a remote client (e.g. when Go is not behinda proxy), can manifest as a vulnerability if your application uses theseheaders for validating the 'trustworthiness' of a request.

funcRecoveryHandler¶

func RecoveryHandler(opts ...RecoveryOption) func(hhttp.Handler)http.Handler

RecoveryHandler is HTTP middleware that recovers from a panic,logs the panic, writes http.StatusInternalServerError, andcontinues to the next handler.

Example:

r := mux.NewRouter()r.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {panic("Unexpected error!")})http.ListenAndServe(":1123", handlers.RecoveryHandler()(r))

typeCORSOption¶

type CORSOption func(*cors)error

CORSOption represents a functional option for configuring the CORS middleware.

func AllowCredentials()CORSOption

func AllowedHeaders(headers []string)CORSOption

func AllowedMethods(methods []string)CORSOption

func AllowedOriginValidator(fnOriginValidator)CORSOption

func AllowedOrigins(origins []string)CORSOption

func ExposedHeaders(headers []string)CORSOption

func IgnoreOptions()CORSOption

func MaxAge(ageint)CORSOption

func OptionStatusCode(codeint)CORSOption

typeLogFormatter¶added inv1.4.0

type LogFormatter func(writerio.Writer, paramsLogFormatterParams)

LogFormatter gives the signature of the formatter function passed to CustomLoggingHandler.

typeLogFormatterParams¶added inv1.4.0

type LogFormatterParams struct {Request    *http.RequestURLurl.URLTimeStamptime.TimeStatusCodeintSizeint}

LogFormatterParams is the structure any formatter will be handed when time to log comes.

typeMethodHandler¶

type MethodHandler map[string]http.Handler

MethodHandler is an http.Handler that dispatches to a handler whose key in theMethodHandler's map matches the name of the HTTP request's method, eg: GET

If the request's method is OPTIONS and OPTIONS is not a key in the map thenthe handler responds with a status of 200 and sets the Allow header to acomma-separated list of available methods.

If the request's method doesn't match any of its keys the handler respondswith a status of HTTP 405 "Method Not Allowed" and sets the Allow header to acomma-separated list of available methods.

func (hMethodHandler) ServeHTTP(whttp.ResponseWriter, req *http.Request)

typeOriginValidator¶

type OriginValidator func(string)bool

OriginValidator takes an origin string and returns whether or not that origin is allowed.

typeRecoveryHandlerLogger¶

type RecoveryHandlerLogger interface {Println(...interface{})}

RecoveryHandlerLogger is an interface used by the recovering handler to print logs.

typeRecoveryOption¶

type RecoveryOption func(http.Handler)

RecoveryOption provides a functional approach to defineconfiguration for a handler; such as setting the loggingwhether or not to print stack traces on panic.

func PrintRecoveryStack(shouldPrintbool)RecoveryOption

func RecoveryLogger(loggerRecoveryHandlerLogger)RecoveryOption