TUN-7057: Remove dependency github.com/gorilla/mux

pull/876/head
Devin Carr 3 months ago
parent 645e22744c
commit 887e486a63

@ -9,6 +9,7 @@ import (
"github.com/gorilla/websocket"
"github.com/rs/zerolog"
"github.com/cloudflare/cloudflared/stream"
"github.com/cloudflare/cloudflared/token"
cfwebsocket "github.com/cloudflare/cloudflared/websocket"
)
@ -37,7 +38,7 @@ func (ws *Websocket) ServeStream(options *StartOptions, conn io.ReadWriter) erro
}
defer wsConn.Close()
cfwebsocket.Stream(wsConn, conn, ws.log)
stream.Pipe(wsConn, conn, ws.log)
return nil
}

@ -10,6 +10,7 @@ import (
"github.com/rs/zerolog"
"github.com/cloudflare/cloudflared/stream"
"github.com/cloudflare/cloudflared/tracing"
tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
"github.com/cloudflare/cloudflared/websocket"
@ -140,7 +141,7 @@ func wsEchoEndpoint(w ResponseWriter, r *http.Request) error {
}()
originConn := &echoPipe{reader: readPipe, writer: writePipe}
websocket.Stream(wsConn, originConn, &log)
stream.Pipe(wsConn, originConn, &log)
cancel()
wsConn.Close()
return nil
@ -178,7 +179,7 @@ func wsFlakyEndpoint(w ResponseWriter, r *http.Request) error {
closedAfter := time.Millisecond * time.Duration(rand.Intn(50))
originConn := &flakyConn{closeAt: time.Now().Add(closedAfter)}
websocket.Stream(wsConn, originConn, &log)
stream.Pipe(wsConn, originConn, &log)
cancel()
wsConn.Close()
return nil

@ -15,7 +15,6 @@ require (
github.com/golang-collections/collections v0.0.0-20130729185459-604e922904d3
github.com/google/gopacket v1.1.19
github.com/google/uuid v1.3.0
github.com/gorilla/mux v1.8.0
github.com/gorilla/websocket v1.4.2
github.com/json-iterator/go v1.1.12
github.com/lucas-clemente/quic-go v0.28.1
@ -36,10 +35,10 @@ require (
go.opentelemetry.io/proto/otlp v0.15.0
go.uber.org/automaxprocs v1.4.0
golang.org/x/crypto v0.2.0
golang.org/x/net v0.2.0
golang.org/x/net v0.4.0
golang.org/x/sync v0.1.0
golang.org/x/sys v0.2.0
golang.org/x/term v0.2.0
golang.org/x/sys v0.3.0
golang.org/x/term v0.3.0
google.golang.org/protobuf v1.28.0
gopkg.in/coreos/go-oidc.v2 v2.2.1
gopkg.in/natefinch/lumberjack.v2 v2.0.0
@ -91,7 +90,7 @@ require (
github.com/russross/blackfriday/v2 v2.1.0 // indirect
golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 // indirect
golang.org/x/oauth2 v0.0.0-20220822191816-0ebed06d0094 // indirect
golang.org/x/text v0.4.0 // indirect
golang.org/x/text v0.5.0 // indirect
golang.org/x/tools v0.1.12 // indirect
google.golang.org/appengine v1.6.7 // indirect
google.golang.org/genproto v0.0.0-20220616135557-88e70c0c3a90 // indirect

@ -357,7 +357,6 @@ github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORR
github.com/gorilla/context v1.1.1/go.mod h1:kBGZzfjB9CEq2AlWe17Uuf7NDRt0dE0s8S51q0aT7Yg=
github.com/gorilla/mux v1.6.2/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
github.com/gorilla/mux v1.7.3/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
github.com/gorilla/securecookie v1.1.1/go.mod h1:ra0sb63/xPlUeL+yeDciTfxMRAA+MP+HVt/4epWDjd4=
github.com/gorilla/sessions v1.2.1/go.mod h1:dk2InVEVJ0sfLlnXv9EAgkf6ecYs/i80K/zI+bUmuGM=
@ -744,8 +743,8 @@ golang.org/x/net v0.0.0-20220425223048-2871e0cb64e4/go.mod h1:CfG3xpIq0wQ8r1q4Su
golang.org/x/net v0.0.0-20220607020251-c690dde0001d/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
golang.org/x/net v0.0.0-20220624214902-1bab6f366d9e/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
golang.org/x/net v0.0.0-20220826154423-83b083e8dc8b/go.mod h1:YDH+HFinaLZZlnHAfSS6ZXJJ9M9t4Dl22yv3iI2vPwk=
golang.org/x/net v0.2.0 h1:sZfSu1wtKLGlWI4ZZayP0ck9Y73K1ynO6gqzTdBVdPU=
golang.org/x/net v0.2.0/go.mod h1:KqCZLdyyvdV855qA2rE3GC2aiw5xGR5TEjj8smXukLY=
golang.org/x/net v0.4.0 h1:Q5QPcMlvfxFTAPV0+07Xz/MpK9NTXu2VDUuy0FeMfaU=
golang.org/x/net v0.4.0/go.mod h1:MBQ8lrhLObU/6UmLb4fmbmk5OcyYmqtbGd/9yIeKjEE=
golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
golang.org/x/oauth2 v0.0.0-20181017192945-9dcd33a902f4/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
golang.org/x/oauth2 v0.0.0-20181203162652-d668ce993890/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
@ -869,13 +868,13 @@ golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBc
golang.org/x/sys v0.0.0-20220610221304-9f5ed59c137d/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.0.0-20220728004956-3c1f35247d10/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.0.0-20220808155132-1c4a2a72c664/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.2.0 h1:ljd4t30dBnAvMZaQCevtY0xLLD0A+bRZXbgLMLU1F/A=
golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.3.0 h1:w8ZOecv6NaNa/zC8944JTU3vz4u6Lagfk4RPQxv92NQ=
golang.org/x/sys v0.3.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
golang.org/x/term v0.0.0-20210615171337-6886f2dfbf5b/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
golang.org/x/term v0.2.0 h1:z85xZCsEl7bi/KwbNADeBYoOP0++7W1ipu+aGnpwzRM=
golang.org/x/term v0.2.0/go.mod h1:TVmDHMZPmdnySmBfhjOoOdhjzdE1h4u1VwSiw2l1Nuc=
golang.org/x/term v0.3.0 h1:qoo4akIqOcDME5bhc/NgxUdovd6BSS2uMsVjB56q1xI=
golang.org/x/term v0.3.0/go.mod h1:q750SLmJuPmVoN1blW3UFBPREJfb1KmY3vwxfr+nFDA=
golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@ -885,8 +884,8 @@ golang.org/x/text v0.3.4/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/text v0.3.5/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
golang.org/x/text v0.4.0 h1:BrVqGRd7+k1DiOgtnFvAkoQEWQvBc25ouMJM6429SFg=
golang.org/x/text v0.4.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
golang.org/x/text v0.5.0 h1:OLmvp0KP+FVG99Ct/qFiL/Fhk4zp4QQnZ7b2U+5piUM=
golang.org/x/text v0.5.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=

@ -9,6 +9,7 @@ import (
"github.com/cloudflare/cloudflared/ipaccess"
"github.com/cloudflare/cloudflared/socks"
"github.com/cloudflare/cloudflared/stream"
"github.com/cloudflare/cloudflared/websocket"
)
@ -25,7 +26,7 @@ type streamHandlerFunc func(originConn io.ReadWriter, remoteConn net.Conn, log *
// DefaultStreamHandler is an implementation of streamHandlerFunc that
// performs a two way io.Copy between originConn and remoteConn.
func DefaultStreamHandler(originConn io.ReadWriter, remoteConn net.Conn, log *zerolog.Logger) {
websocket.Stream(originConn, remoteConn, log)
stream.Pipe(originConn, remoteConn, log)
}
// tcpConnection is an OriginConnection that directly streams to raw TCP.
@ -34,7 +35,7 @@ type tcpConnection struct {
}
func (tc *tcpConnection) Stream(ctx context.Context, tunnelConn io.ReadWriter, log *zerolog.Logger) {
websocket.Stream(tunnelConn, tc.conn, log)
stream.Pipe(tunnelConn, tc.conn, log)
}
func (tc *tcpConnection) Close() {

@ -22,6 +22,7 @@ import (
"github.com/cloudflare/cloudflared/logger"
"github.com/cloudflare/cloudflared/socks"
"github.com/cloudflare/cloudflared/stream"
"github.com/cloudflare/cloudflared/websocket"
)
@ -50,6 +51,7 @@ func TestStreamTCPConnection(t *testing.T) {
errGroup, ctx := errgroup.WithContext(ctx)
errGroup.Go(func() error {
_, err := eyeballConn.Write(testMessage)
require.NoError(t, err)
readBuffer := make([]byte, len(testResponse))
_, err = eyeballConn.Read(readBuffer)
@ -158,7 +160,7 @@ func TestSocksStreamWSOverTCPConnection(t *testing.T) {
require.NoError(t, err)
defer wsForwarderInConn.Close()
websocket.Stream(wsForwarderInConn, &wsEyeball{wsForwarderOutConn}, testLogger)
stream.Pipe(wsForwarderInConn, &wsEyeball{wsForwarderOutConn}, testLogger)
return nil
})

@ -10,7 +10,6 @@ import (
"sync"
"time"
"github.com/gorilla/mux"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"github.com/rs/zerolog"
@ -37,10 +36,8 @@ type orchestrator interface {
func newMetricsHandler(
config Config,
log *zerolog.Logger,
) *mux.Router {
router := mux.NewRouter()
router.PathPrefix("/debug/").Handler(http.DefaultServeMux)
) *http.ServeMux {
router := http.NewServeMux()
router.Handle("/metrics", promhttp.Handler())
router.HandleFunc("/healthcheck", func(w http.ResponseWriter, r *http.Request) {
_, _ = fmt.Fprintf(w, "OK\n")

@ -16,9 +16,9 @@ import (
"github.com/cloudflare/cloudflared/cfio"
"github.com/cloudflare/cloudflared/connection"
"github.com/cloudflare/cloudflared/ingress"
"github.com/cloudflare/cloudflared/stream"
"github.com/cloudflare/cloudflared/tracing"
tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
"github.com/cloudflare/cloudflared/websocket"
)
const (
@ -257,7 +257,7 @@ func (p *Proxy) proxyHTTPRequest(
reader: tr.Request.Body,
}
websocket.Stream(eyeballStream, rwc, p.log)
stream.Pipe(eyeballStream, rwc, p.log)
return nil
}

@ -0,0 +1,135 @@
package stream
import (
"encoding/hex"
"fmt"
"io"
"runtime/debug"
"sync/atomic"
"time"
"github.com/getsentry/raven-go"
"github.com/pkg/errors"
"github.com/rs/zerolog"
"github.com/cloudflare/cloudflared/cfio"
)
type bidirectionalStreamStatus struct {
doneChan chan struct{}
anyDone uint32
}
func newBiStreamStatus() *bidirectionalStreamStatus {
return &bidirectionalStreamStatus{
doneChan: make(chan struct{}, 2),
anyDone: 0,
}
}
func (s *bidirectionalStreamStatus) markUniStreamDone() {
atomic.StoreUint32(&s.anyDone, 1)
s.doneChan <- struct{}{}
}
func (s *bidirectionalStreamStatus) waitAnyDone() {
<-s.doneChan
}
func (s *bidirectionalStreamStatus) isAnyDone() bool {
return atomic.LoadUint32(&s.anyDone) > 0
}
// Pipe copies copy data to & from provided io.ReadWriters.
func Pipe(tunnelConn, originConn io.ReadWriter, log *zerolog.Logger) {
status := newBiStreamStatus()
go unidirectionalStream(tunnelConn, originConn, "origin->tunnel", status, log)
go unidirectionalStream(originConn, tunnelConn, "tunnel->origin", status, log)
// If one side is done, we are done.
status.waitAnyDone()
}
func unidirectionalStream(dst io.Writer, src io.Reader, dir string, status *bidirectionalStreamStatus, log *zerolog.Logger) {
defer func() {
// The bidirectional streaming spawns 2 goroutines to stream each direction.
// If any ends, the callstack returns, meaning the Tunnel request/stream (depending on http2 vs quic) will
// close. In such case, if the other direction did not stop (due to application level stopping, e.g., if a
// server/origin listens forever until closure), it may read/write from the underlying ReadWriter (backed by
// the Edge<->cloudflared transport) in an unexpected state.
// Because of this, we set this recover() logic.
if r := recover(); r != nil {
if status.isAnyDone() {
// We handle such unexpected errors only when we detect that one side of the streaming is done.
log.Debug().Msgf("Gracefully handled error %v in Streaming for %s, error %s", r, dir, debug.Stack())
} else {
// Otherwise, this is unexpected, but we prevent the program from crashing anyway.
log.Warn().Msgf("Gracefully handled unexpected error %v in Streaming for %s, error %s", r, dir, debug.Stack())
tags := make(map[string]string)
tags["root"] = "websocket.stream"
tags["dir"] = dir
switch rval := r.(type) {
case error:
raven.CaptureError(rval, tags)
default:
rvalStr := fmt.Sprint(rval)
raven.CaptureMessage(rvalStr, tags)
}
}
}
}()
_, err := copyData(dst, src, dir)
if err != nil {
log.Debug().Msgf("%s copy: %v", dir, err)
}
status.markUniStreamDone()
}
// when set to true, enables logging of content copied to/from origin and tunnel
const debugCopy = false
func copyData(dst io.Writer, src io.Reader, dir string) (written int64, err error) {
if debugCopy {
// copyBuffer is based on stdio Copy implementation but shows copied data
copyBuffer := func(dst io.Writer, src io.Reader, dir string) (written int64, err error) {
var buf []byte
size := 32 * 1024
buf = make([]byte, size)
for {
t := time.Now()
nr, er := src.Read(buf)
if nr > 0 {
fmt.Println(dir, t.UnixNano(), "\n"+hex.Dump(buf[0:nr]))
nw, ew := dst.Write(buf[0:nr])
if nw < 0 || nr < nw {
nw = 0
if ew == nil {
ew = errors.New("invalid write")
}
}
written += int64(nw)
if ew != nil {
err = ew
break
}
if nr != nw {
err = io.ErrShortWrite
break
}
}
if er != nil {
if er != io.EOF {
err = er
}
break
}
}
return written, err
}
return copyBuffer(dst, src, dir)
} else {
return cfio.Copy(dst, src)
}
}

@ -1,8 +0,0 @@
# This is the official list of gorilla/mux authors for copyright purposes.
#
# Please keep the list sorted.
Google LLC (https://opensource.google.com/)
Kamil Kisielk <kamil@kamilkisiel.net>
Matt Silverlock <matt@eatsleeprepeat.net>
Rodrigo Moraes (https://github.com/moraes)

@ -1,27 +0,0 @@
Copyright (c) 2012-2018 The Gorilla Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@ -1,805 +0,0 @@
# gorilla/mux
[![GoDoc](https://godoc.org/github.com/gorilla/mux?status.svg)](https://godoc.org/github.com/gorilla/mux)
[![CircleCI](https://circleci.com/gh/gorilla/mux.svg?style=svg)](https://circleci.com/gh/gorilla/mux)
[![Sourcegraph](https://sourcegraph.com/github.com/gorilla/mux/-/badge.svg)](https://sourcegraph.com/github.com/gorilla/mux?badge)
![Gorilla Logo](https://cloud-cdn.questionable.services/gorilla-icon-64.png)
https://www.gorillatoolkit.org/pkg/mux
Package `gorilla/mux` implements a request router and dispatcher for matching incoming requests to
their respective handler.
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:
* It implements the `http.Handler` interface so it is compatible with the standard `http.ServeMux`.
* Requests can be matched based on URL host, path, path prefix, schemes, header and query values, HTTP methods or using custom matchers.
* URL hosts, paths and query values can have variables with an optional regular expression.
* Registered URLs can be built, or "reversed", which helps maintaining references to resources.
* Routes can be used as subrouters: nested routes are only tested if the parent route matches. This is useful to define groups of routes that share common conditions like a host, a path prefix or other repeated attributes. As a bonus, this optimizes request matching.
---
* [Install](#install)
* [Examples](#examples)
* [Matching Routes](#matching-routes)
* [Static Files](#static-files)
* [Serving Single Page Applications](#serving-single-page-applications) (e.g. React, Vue, Ember.js, etc.)
* [Registered URLs](#registered-urls)
* [Walking Routes](#walking-routes)
* [Graceful Shutdown](#graceful-shutdown)
* [Middleware](#middleware)
* [Handling CORS Requests](#handling-cors-requests)
* [Testing Handlers](#testing-handlers)
* [Full Example](#full-example)
---
## Install
With a [correctly configured](https://golang.org/doc/install#testing) Go toolchain:
```sh
go get -u github.com/gorilla/mux
```
## Examples
Let's start registering a couple of URL paths and handlers:
```go
func main() {
r := mux.NewRouter()
r.HandleFunc("/", HomeHandler)
r.HandleFunc("/products", ProductsHandler)
r.HandleFunc("/articles", ArticlesHandler)
http.Handle("/", r)
}
```
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:
```go
r := mux.NewRouter()
r.HandleFunc("/products/{key}", ProductHandler)
r.HandleFunc("/articles/{category}/", ArticlesCategoryHandler)
r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler)
```
The names are used to create a map of route variables which can be retrieved calling `mux.Vars()`:
```go
func ArticlesCategoryHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
w.WriteHeader(http.StatusOK)
fmt.Fprintf(w, "Category: %v\n", vars["category"])
}
```
And this is all you need to know about the basic usage. More advanced options are explained below.
### Matching Routes
Routes can also be restricted to a domain or subdomain. Just define a host pattern to be matched. They can also have variables:
```go
r := mux.NewRouter()
// Only matches if domain is "www.example.com".
r.Host("www.example.com")
// Matches a dynamic subdomain.
r.Host("{subdomain:[a-z]+}.example.com")
```
There are several other matchers that can be added. To match path prefixes:
```go
r.PathPrefix("/products/")
```
...or HTTP methods:
```go
r.Methods("GET", "POST")
```
...or URL schemes:
```go
r.Schemes("https")
```
...or header values:
```go
r.Headers("X-Requested-With", "XMLHttpRequest")
```
...or query values:
```go
r.Queries("key", "value")
```
...or to use a custom matcher function:
```go
r.MatcherFunc(func(r *http.Request, rm *RouteMatch) bool {
return r.ProtoMajor == 0
})
```
...and finally, it is possible to combine several matchers in a single route:
```go
r.HandleFunc("/products", ProductsHandler).
Host("www.example.com").
Methods("GET").
Schemes("http")
```
Routes are tested in the order they were added to the router. If two routes match, the first one wins:
```go
r := mux.NewRouter()
r.HandleFunc("/specific", specificHandler)
r.PathPrefix("/").Handler(catchAllHandler)
```
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:
```go
r := mux.NewRouter()
s := r.Host("www.example.com").Subrouter()
```
Then register routes in the subrouter:
```go
s.HandleFunc("/products/", ProductsHandler)
s.HandleFunc("/products/{key}", ProductHandler)
s.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler)
```
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:
```go
r := mux.NewRouter()
s := r.PathPrefix("/products").Subrouter()
// "/products/"
s.HandleFunc("/", ProductsHandler)
// "/products/{key}/"
s.HandleFunc("/{key}/", ProductHandler)
// "/products/{key}/details"
s.HandleFunc("/{key}/details", ProductDetailsHandler)
```
### Static Files
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:
```go
func main() {
var dir string
flag.StringVar(&dir, "dir", ".", "the directory to serve files from. Defaults to the current dir")
flag.Parse()
r := mux.NewRouter()
// This will serve files under http://localhost:8000/static/<filename>
r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir(dir))))
srv := &http.Server{
Handler: r,
Addr: "127.0.0.1:8000",
// Good practice: enforce timeouts for servers you create!
WriteTimeout: 15 * time.Second,
ReadTimeout: 15 * time.Second,
}
log.Fatal(srv.ListenAndServe())
}
```
### Serving Single Page Applications
Most of the time it makes sense to serve your SPA on a separate web server from your API,
but sometimes it's desirable to serve them both from one place. It's possible to write a simple
handler for serving your SPA (for use with React Router's [BrowserRouter](https://reacttraining.com/react-router/web/api/BrowserRouter) for example), and leverage
mux's powerful routing for your API endpoints.
```go
package main
import (
"encoding/json"
"log"
"net/http"
"os"
"path/filepath"
"time"
"github.com/gorilla/mux"
)
// spaHandler implements the http.Handler interface, so we can use it
// to respond to HTTP requests. The path to the static directory and
// path to the index file within that static directory are used to
// serve the SPA in the given static directory.
type spaHandler struct {
staticPath string
indexPath string
}
// ServeHTTP inspects the URL path to locate a file within the static dir
// on the SPA handler. If a file is found, it will be served. If not, the
// file located at the index path on the SPA handler will be served. This
// is suitable behavior for serving an SPA (single page application).
func (h spaHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// get the absolute path to prevent directory traversal
path, err := filepath.Abs(r.URL.Path)
if err != nil {
// if we failed to get the absolute path respond with a 400 bad request
// and stop
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
// prepend the path with the path to the static directory
path = filepath.Join(h.staticPath, path)
// check whether a file exists at the given path
_, err = os.Stat(path)
if os.IsNotExist(err) {
// file does not exist, serve index.html
http.ServeFile(w, r, filepath.Join(h.staticPath, h.indexPath))
return
} else if err != nil {
// if we got an error (that wasn't that the file doesn't exist) stating the
// file, return a 500 internal server error and stop
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
// otherwise, use http.FileServer to serve the static dir
http.FileServer(http.Dir(h.staticPath)).ServeHTTP(w, r)
}
func main() {
router := mux.NewRouter()
router.HandleFunc("/api/health", func(w http.ResponseWriter, r *http.Request) {
// an example API handler
json.NewEncoder(w).Encode(map[string]bool{"ok": true})
})
spa := spaHandler{staticPath: "build", indexPath: "index.html"}
router.PathPrefix("/").Handler(spa)
srv := &http.Server{
Handler: router,
Addr: "127.0.0.1:8000",
// Good practice: enforce timeouts for servers you create!
WriteTimeout: 15 * time.Second,
ReadTimeout: 15 * time.Second,
}
log.Fatal(srv.ListenAndServe())
}
```
### Registered URLs
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:
```go
r := mux.NewRouter()
r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
Name("article")
```
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:
```go
url, err := r.Get("article").URL("category", "technology", "id", "42")
```
...and the result will be a `url.URL` with the following path:
```
"/articles/technology/42"
```
This also works for host and query value variables:
```go
r := mux.NewRouter()
r.Host("{subdomain}.example.com").
Path("/articles/{category}/{id:[0-9]+}").
Queries("filter", "{filter}").
HandlerFunc(ArticleHandler).
Name("article")
// url.String() will be "http://news.example.com/articles/technology/42?filter=gorilla"
url, err := r.Get("article").URL("subdomain", "news",
"category", "technology",
"id", "42",
"filter", "gorilla")
```
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:
```go
r.HeadersRegexp("Content-Type", "application/(text|json)")
```
...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:
```go
// "http://news.example.com/"
host, err := r.Get("article").URLHost("subdomain", "news")
// "/articles/technology/42"
path, err := r.Get("article").URLPath("category", "technology", "id", "42")
```
And if you use subrouters, host and path defined separately can be built as well:
```go
r := mux.NewRouter()
s := r.Host("{subdomain}.example.com").Subrouter()
s.Path("/articles/{category}/{id:[0-9]+}").
HandlerFunc(ArticleHandler).
Name("article")
// "http://news.example.com/articles/technology/42"
url, err := r.Get("article").URL("subdomain", "news",
"category", "technology",
"id", "42")
```
### Walking Routes
The `Walk` function on `mux.Router` can be used to visit all of the routes that are registered on a router. For example,
the following prints all of the registered routes:
```go
package main
import (
"fmt"
"net/http"
"strings"
"github.com/gorilla/mux"
)
func handler(w http.ResponseWriter, r *http.Request) {
return
}
func main() {
r := mux.NewRouter()
r.HandleFunc("/", handler)
r.HandleFunc("/products", handler).Methods("POST")
r.HandleFunc("/articles", handler).Methods("GET")
r.HandleFunc("/articles/{id}", handler).Methods("GET", "PUT")
r.HandleFunc("/authors", handler).Queries("surname", "{surname}")
err := r.Walk(func(route *mux.Route, router *mux.Router, ancestors []*mux.Route) error {
pathTemplate, err := route.GetPathTemplate()
if err == nil {
fmt.Println("ROUTE:", pathTemplate)
}
pathRegexp, err := route.GetPathRegexp()
if err == nil {
fmt.Println("Path regexp:", pathRegexp)
}
queriesTemplates, err := route.GetQueriesTemplates()
if err == nil {
fmt.Println("Queries templates:", strings.Join(queriesTemplates, ","))
}
queriesRegexps, err := route.GetQueriesRegexp()
if err == nil {
fmt.Println("Queries regexps:", strings.Join(queriesRegexps, ","))
}
methods, err := route.GetMethods()
if err == nil {
fmt.Println("Methods:", strings.Join(methods, ","))
}
fmt.Println()
return nil
})
if err != nil {
fmt.Println(err)
}
http.Handle("/", r)
}
```
### Graceful Shutdown
Go 1.8 introduced the ability to [gracefully shutdown](https://golang.org/doc/go1.8#http_shutdown) a `*http.Server`. Here's how to do that alongside `mux`:
```go
package main
import (
"context"
"flag"
"log"
"net/http"
"os"
"os/signal"
"time"
"github.com/gorilla/mux"
)
func main() {
var wait time.Duration
flag.DurationVar(&wait, "graceful-timeout", time.Second * 15, "the duration for which the server gracefully wait for existing connections to finish - e.g. 15s or 1m")
flag.Parse()
r := mux.NewRouter()
// Add your routes as needed
srv := &http.Server{
Addr: "0.0.0.0:8080",
// Good practice to set timeouts to avoid Slowloris attacks.
WriteTimeout: time.Second * 15,
ReadTimeout: time.Second * 15,
IdleTimeout: time.Second * 60,
Handler: r, // Pass our instance of gorilla/mux in.
}
// Run our server in a goroutine so that it doesn't block.
go func() {
if err := srv.ListenAndServe(); err != nil {
log.Println(err)
}
}()
c := make(chan os.Signal, 1)
// We'll accept graceful shutdowns when quit via SIGINT (Ctrl+C)
// SIGKILL, SIGQUIT or SIGTERM (Ctrl+/) will not be caught.
signal.Notify(c, os.Interrupt)
// Block until we receive our signal.
<-c
// Create a deadline to wait for.
ctx, cancel := context.WithTimeout(context.Background(), wait)
defer cancel()
// Doesn't block if no connections, but will otherwise wait
// until the timeout deadline.
srv.Shutdown(ctx)
// Optionally, you could run srv.Shutdown in a goroutine and block on
// <-ctx.Done() if your application should wait for other services
// to finalize based on context cancellation.
log.Println("shutting down")
os.Exit(0)
}
```
### Middleware
Mux supports the addition of middlewares to a [Router](https://godoc.org/github.com/gorilla/mux#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.
Mux middlewares are defined using the de facto standard type:
```go
type MiddlewareFunc func(http.Handler) http.Handler
```
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. This takes advantage of closures being able access variables from the context where they are created, while retaining the signature enforced by the receivers.
A very basic middleware which logs the URI of the request being handled could be written as:
```go
func loggingMiddleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Do stuff here
log.Println(r.RequestURI)
// Call the next handler, which can be another middleware in the chain, or the final handler.
next.ServeHTTP(w, r)
})
}
```
Middlewares can be added to a router using `Router.Use()`:
```go
r := mux.NewRouter()
r.HandleFunc("/", handler)
r.Use(loggingMiddleware)
```
A more complex authentication middleware, which maps session token to users, could be written as:
```go
// Define our struct
type authenticationMiddleware struct {
tokenUsers map[string]string
}
// Initialize it somewhere
func (amw *authenticationMiddleware) Populate() {
amw.tokenUsers["00000000"] = "user0"
amw.tokenUsers["aaaaaaaa"] = "userA"
amw.tokenUsers["05f717e5"] = "randomUser"
amw.tokenUsers["deadbeef"] = "user0"
}
// Middleware function, which will be called for each request
func (amw *authenticationMiddleware) Middleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
token := r.Header.Get("X-Session-Token")
if user, found := amw.tokenUsers[token]; found {
// We found the token in our map
log.Printf("Authenticated user %s\n", user)
// Pass down the request to the next middleware (or final handler)
next.ServeHTTP(w, r)
} else {
// Write an error and stop the handler chain
http.Error(w, "Forbidden", http.StatusForbidden)
}
})
}
```
```go
r := mux.NewRouter()
r.HandleFunc("/", handler)
amw := authenticationMiddleware{}
amw.Populate()
r.Use(amw.Middleware)
```
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. Middlewares _should_ write to `ResponseWriter` if they _are_ going to terminate the request, and they _should not_ write to `ResponseWriter` if they _are not_ going to terminate it.
### Handling CORS Requests
[CORSMethodMiddleware](https://godoc.org/github.com/gorilla/mux#CORSMethodMiddleware) intends to make it easier to strictly set the `Access-Control-Allow-Methods` response header.
* You will still need to use your own CORS handler to set the other CORS headers such as `Access-Control-Allow-Origin`
* The middleware will set the `Access-Control-Allow-Methods` header to all the method matchers (e.g. `r.Methods(http.MethodGet, http.MethodPut, http.MethodOptions)` -> `Access-Control-Allow-Methods: GET,PUT,OPTIONS`) on a route
* If you do not specify any methods, then:
> _Important_: there must be an `OPTIONS` method matcher for the middleware to set the headers.
Here is an example of using `CORSMethodMiddleware` along with a custom `OPTIONS` handler to set all the required CORS headers:
```go
package main
import (
"net/http"
"github.com/gorilla/mux"
)
func main() {
r := mux.NewRouter()
// IMPORTANT: you must specify an OPTIONS method matcher for the middleware to set CORS headers
r.HandleFunc("/foo", fooHandler).Methods(http.MethodGet, http.MethodPut, http.MethodPatch, http.MethodOptions)
r.Use(mux.CORSMethodMiddleware(r))
http.ListenAndServe(":8080", r)
}
func fooHandler(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Access-Control-Allow-Origin", "*")
if r.Method == http.MethodOptions {
return
}
w.Write([]byte("foo"))
}
```
And an request to `/foo` using something like:
```bash
curl localhost:8080/foo -v
```
Would look like:
```bash
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8080 (#0)
> GET /foo HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.59.0
> Accept: */*
>
< HTTP/1.1 200 OK
< Access-Control-Allow-Methods: GET,PUT,PATCH,OPTIONS
< Access-Control-Allow-Origin: *
< Date: Fri, 28 Jun 2019 20:13:30 GMT
< Content-Length: 3
< Content-Type: text/plain; charset=utf-8
<
* Connection #0 to host localhost left intact
foo
```
### Testing Handlers
Testing handlers in a Go web application is straightforward, and _mux_ doesn't complicate this any further. Given two files: `endpoints.go` and `endpoints_test.go`, here's how we'd test an application using _mux_.
First, our simple HTTP handler:
```go
// endpoints.go
package main
func HealthCheckHandler(w http.ResponseWriter, r *http.Request) {
// A very simple health check.
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
// In the future we could report back on the status of our DB, or our cache
// (e.g. Redis) by performing a simple PING, and include them in the response.
io.WriteString(w, `{"alive": true}`)
}
func main() {
r := mux.NewRouter()
r.HandleFunc("/health", HealthCheckHandler)
log.Fatal(http.ListenAndServe("localhost:8080", r))
}
```
Our test code:
```go
// endpoints_test.go
package main
import (
"net/http"
"net/http/httptest"
"testing"
)
func TestHealthCheckHandler(t *testing.T) {
// Create a request to pass to our handler. We don't have any query parameters for now, so we'll
// pass 'nil' as the third parameter.
req, err := http.NewRequest("GET", "/health", nil)
if err != nil {
t.Fatal(err)
}
// We create a ResponseRecorder (which satisfies http.ResponseWriter) to record the response.
rr := httptest.NewRecorder()
handler := http.HandlerFunc(HealthCheckHandler)
// Our handlers satisfy http.Handler, so we can call their ServeHTTP method
// directly and pass in our Request and ResponseRecorder.
handler.ServeHTTP(rr, req)
// Check the status code is what we expect.
if status := rr.Code; status != http.StatusOK {
t.Errorf("handler returned wrong status code: got %v want %v",
status, http.StatusOK)
}
// Check the response body is what we expect.
expected := `{"alive": true}`
if rr.Body.String() != expected {
t.Errorf("handler returned unexpected body: got %v want %v",
rr.Body.String(), expected)
}
}
```
In the case that our routes have [variables](#examples), we can pass those in the request. We could write
[table-driven tests](https://dave.cheney.net/2013/06/09/writing-table-driven-tests-in-go) to test multiple
possible route variables as needed.
```go
// endpoints.go
func main() {
r := mux.NewRouter()
// A route with a route variable:
r.HandleFunc("/metrics/{type}", MetricsHandler)
log.Fatal(http.ListenAndServe("localhost:8080", r))
}
```
Our test file, with a table-driven test of `routeVariables`:
```go
// endpoints_test.go
func TestMetricsHandler(t *testing.T) {
tt := []struct{
routeVariable string
shouldPass bool
}{
{"goroutines", true},
{"heap", true},
{"counters", true},
{"queries", true},
{"adhadaeqm3k", false},
}
for _, tc := range tt {
path := fmt.Sprintf("/metrics/%s", tc.routeVariable)
req, err := http.NewRequest("GET", path, nil)
if err != nil {
t.Fatal(err)
}
rr := httptest.NewRecorder()
// Need to create a router that we can pass the request through so that the vars will be added to the context
router := mux.NewRouter()
router.HandleFunc("/metrics/{type}", MetricsHandler)
router.ServeHTTP(rr, req)
// In this case, our MetricsHandler returns a non-200 response
// for a route variable it doesn't know about.
if rr.Code == http.StatusOK && !tc.shouldPass {
t.Errorf("handler should have failed on routeVariable %s: got %v want %v",
tc.routeVariable, rr.Code, http.StatusOK)
}
}
}
```
## Full Example
Here's a complete, runnable example of a small `mux` based server:
```go
package main
import (
"net/http"
"log"
"github.com/gorilla/mux"
)
func YourHandler(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Gorilla!\n"))
}
func main() {
r := mux.NewRouter()
// Routes consist of a path and a handler function.
r.HandleFunc("/", YourHandler)
// Bind to a port and pass our router in
log.Fatal(http.ListenAndServe(":8000", r))
}
```
## License
BSD licensed. See the LICENSE file for details.

@ -1,306 +0,0 @@
// Copyright 2012 The Gorilla 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 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:
* Requests can be matched based on URL host, path, path prefix, schemes,
header and query values, HTTP methods or using custom matchers.
* URL hosts, paths and query values can have variables with an optional
regular expression.
* Registered URLs can be built, or "reversed", which helps maintaining
references to resources.
* Routes can be used as subrouters: nested routes are only tested if the
parent route matches. This is useful to define groups of routes that
share common conditions like a host, a path prefix or other repeated
attributes. As a bonus, this optimizes request matching.
* It implements the http.Handler interface so it is compatible with the
standard http.ServeMux.
Let's start registering a couple of URL paths and handlers:
func main() {
r := mux.NewRouter()
r.HandleFunc("/", HomeHandler)
r.HandleFunc("/products", ProductsHandler)
r.HandleFunc("/articles", ArticlesHandler)
http.Handle("/", r)
}
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:
r := mux.NewRouter()
r.HandleFunc("/products/{key}", ProductHandler)
r.HandleFunc("/articles/{category}/", ArticlesCategoryHandler)
r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler)
Groups can be used inside patterns, as long as they are non-capturing (?:re). For example:
r.HandleFunc("/articles/{category}/{sort:(?:asc|desc|new)}", ArticlesCategoryHandler)
The names are used to create a map of route variables which can be retrieved
calling mux.Vars():
vars := mux.Vars(request)
category := vars["category"]
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:
r := mux.NewRouter()
// Only matches if domain is "www.example.com".
r.Host("www.example.com")
// Matches a dynamic subdomain.
r.Host("{subdomain:[a-z]+}.domain.com")
There are several other matchers that can be added. To match path prefixes:
r.PathPrefix("/products/")
...or HTTP methods:
r.Methods("GET", "POST")
...or URL schemes:
r.Schemes("https")
...or header values:
r.Headers("X-Requested-With", "XMLHttpRequest")
...or query values:
r.Queries("key", "value")
...or to use a custom matcher function:
r.MatcherFunc(func(r *http.Request, rm *RouteMatch) bool {
return r.ProtoMajor == 0
})
...and finally, it is possible to combine several matchers in a single route:
r.HandleFunc("/products", ProductsHandler).
Host("www.example.com").
Methods("GET").
Schemes("http")
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:
r := mux.NewRouter()
s := r.Host("www.example.com").Subrouter()
Then register routes in the subrouter:
s.HandleFunc("/products/", ProductsHandler)
s.HandleFunc("/products/{key}", ProductHandler)
s.HandleFunc("/articles/{category}/{id:[0-9]+}"), ArticleHandler)
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:
r := mux.NewRouter()
s := r.PathPrefix("/products").Subrouter()
// "/products/"
s.HandleFunc("/", ProductsHandler)
// "/products/{key}/"
s.HandleFunc("/{key}/", ProductHandler)
// "/products/{key}/details"
s.HandleFunc("/{key}/details", ProductDetailsHandler)
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:
func main() {
var dir string
flag.StringVar(&dir, "dir", ".", "the directory to serve files from. Defaults to the current dir")
flag.Parse()
r := mux.NewRouter()
// This will serve files under http://localhost:8000/static/<filename>
r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir(dir))))
srv := &http.Server{
Handler: r,
Addr: "127.0.0.1:8000",
// Good practice: enforce timeouts for servers you create!
WriteTimeout: 15 * time.Second,
ReadTimeout: 15 * time.Second,
}
log.Fatal(srv.ListenAndServe())
}
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:
r := mux.NewRouter()
r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).
Name("article")
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:
url, err := r.Get("article").URL("category", "technology", "id", "42")
...and the result will be a url.URL with the following path:
"/articles/technology/42"
This also works for host and query value variables:
r := mux.NewRouter()
r.Host("{subdomain}.domain.com").
Path("/articles/{category}/{id:[0-9]+}").
Queries("filter", "{filter}").
HandlerFunc(ArticleHandler).
Name("article")
// url.String() will be "http://news.domain.com/articles/technology/42?filter=gorilla"
url, err := r.Get("article").URL("subdomain", "news",
"category", "technology",
"id", "42",
"filter", "gorilla")
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:
r.HeadersRegexp("Content-Type", "application/(text|json)")
...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:
// "http://news.domain.com/"
host, err := r.Get("article").URLHost("subdomain", "news")
// "/articles/technology/42"
path, err := r.Get("article").URLPath("category", "technology", "id", "42")
And if you use subrouters, host and path defined separately can be built
as well:
r := mux.NewRouter()
s := r.Host("{subdomain}.domain.com").Subrouter()
s.Path("/articles/{category}/{id:[0-9]+}").
HandlerFunc(ArticleHandler).
Name("article")
// "http://news.domain.com/articles/technology/42"
url, err := r.Get("article").URL("subdomain", "news",
"category", "technology",
"id", "42")
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.
type MiddlewareFunc func(http.Handler) http.Handler
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:
func simpleMw(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Do stuff here
log.Println(r.RequestURI)
// Call the next handler, which can be another middleware in the chain, or the final handler.
next.ServeHTTP(w, r)
})
}
Middlewares can be added to a router using `Router.Use()`:
r := mux.NewRouter()
r.HandleFunc("/", handler)
r.Use(simpleMw)
A more complex authentication middleware, which maps session token to users, could be written as:
// Define our struct
type authenticationMiddleware struct {
tokenUsers map[string]string
}
// Initialize it somewhere
func (amw *authenticationMiddleware) Populate() {
amw.tokenUsers["00000000"] = "user0"
amw.tokenUsers["aaaaaaaa"] = "userA"
amw.tokenUsers["05f717e5"] = "randomUser"
amw.tokenUsers["deadbeef"] = "user0"
}
// Middleware function, which will be called for each request
func (amw *authenticationMiddleware) Middleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
token := r.Header.Get("X-Session-Token")
if user, found := amw.tokenUsers[token]; found {
// We found the token in our map
log.Printf("Authenticated user %s\n", user)
next.ServeHTTP(w, r)
} else {
http.Error(w, "Forbidden", http.StatusForbidden)
}
})
}
r := mux.NewRouter()
r.HandleFunc("/", handler)
amw := authenticationMiddleware{tokenUsers: make(map[string]string)}
amw.Populate()
r.Use(amw.Middleware)
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 mux

@ -1,74 +0,0 @@
package mux
import (
"net/http"
"strings"
)
// MiddlewareFunc is a function which receives an http.Handler and returns another http.Handler.
// 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.
type MiddlewareFunc func(http.Handler) http.Handler
// middleware interface is anything which implements a MiddlewareFunc named Middleware.