diff options
Diffstat (limited to 'vendor/github.com/gorilla/websocket/examples/command')
-rw-r--r-- | vendor/github.com/gorilla/websocket/examples/command/main.go | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/vendor/github.com/gorilla/websocket/examples/command/main.go b/vendor/github.com/gorilla/websocket/examples/command/main.go new file mode 100644 index 00000000..f3f022ed --- /dev/null +++ b/vendor/github.com/gorilla/websocket/examples/command/main.go @@ -0,0 +1,188 @@ +// Copyright 2015 The Gorilla WebSocket 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 main + +import ( + "bufio" + "flag" + "io" + "log" + "net/http" + "os" + "os/exec" + "text/template" + "time" + + "github.com/gorilla/websocket" +) + +var ( + addr = flag.String("addr", "127.0.0.1:8080", "http service address") + cmdPath string + homeTempl = template.Must(template.ParseFiles("home.html")) +) + +const ( + // Time allowed to write a message to the peer. + writeWait = 10 * time.Second + + // Maximum message size allowed from peer. + maxMessageSize = 8192 + + // Time allowed to read the next pong message from the peer. + pongWait = 60 * time.Second + + // Send pings to peer with this period. Must be less than pongWait. + pingPeriod = (pongWait * 9) / 10 +) + +func pumpStdin(ws *websocket.Conn, w io.Writer) { + defer ws.Close() + ws.SetReadLimit(maxMessageSize) + ws.SetReadDeadline(time.Now().Add(pongWait)) + ws.SetPongHandler(func(string) error { ws.SetReadDeadline(time.Now().Add(pongWait)); return nil }) + for { + _, message, err := ws.ReadMessage() + if err != nil { + break + } + message = append(message, '\n') + if _, err := w.Write(message); err != nil { + break + } + } +} + +func pumpStdout(ws *websocket.Conn, r io.Reader, done chan struct{}) { + defer func() { + ws.Close() + close(done) + }() + s := bufio.NewScanner(r) + for s.Scan() { + ws.SetWriteDeadline(time.Now().Add(writeWait)) + if err := ws.WriteMessage(websocket.TextMessage, s.Bytes()); err != nil { + break + } + } + if s.Err() != nil { + log.Println("scan:", s.Err()) + } +} + +func ping(ws *websocket.Conn, done chan struct{}) { + ticker := time.NewTicker(pingPeriod) + defer ticker.Stop() + for { + select { + case <-ticker.C: + if err := ws.WriteControl(websocket.PingMessage, []byte{}, time.Now().Add(writeWait)); err != nil { + log.Println("ping:", err) + } + case <-done: + return + } + } +} + +func internalError(ws *websocket.Conn, msg string, err error) { + log.Println(msg, err) + ws.WriteMessage(websocket.TextMessage, []byte("Internal server error.")) +} + +var upgrader = websocket.Upgrader{} + +func serveWs(w http.ResponseWriter, r *http.Request) { + ws, err := upgrader.Upgrade(w, r, nil) + if err != nil { + log.Println("upgrade:", err) + return + } + + defer ws.Close() + + outr, outw, err := os.Pipe() + if err != nil { + internalError(ws, "stdout:", err) + return + } + defer outr.Close() + defer outw.Close() + + inr, inw, err := os.Pipe() + if err != nil { + internalError(ws, "stdin:", err) + return + } + defer inr.Close() + defer inw.Close() + + proc, err := os.StartProcess(cmdPath, flag.Args(), &os.ProcAttr{ + Files: []*os.File{inr, outw, outw}, + }) + if err != nil { + internalError(ws, "start:", err) + return + } + + inr.Close() + outw.Close() + + stdoutDone := make(chan struct{}) + go pumpStdout(ws, outr, stdoutDone) + go ping(ws, stdoutDone) + + pumpStdin(ws, inw) + + // Some commands will exit when stdin is closed. + inw.Close() + + // Other commands need a bonk on the head. + if err := proc.Signal(os.Interrupt); err != nil { + log.Println("inter:", err) + } + + select { + case <-stdoutDone: + case <-time.After(time.Second): + // A bigger bonk on the head. + if err := proc.Signal(os.Kill); err != nil { + log.Println("term:", err) + } + <-stdoutDone + } + + if _, err := proc.Wait(); err != nil { + log.Println("wait:", err) + } +} + +func serveHome(w http.ResponseWriter, r *http.Request) { + if r.URL.Path != "/" { + http.Error(w, "Not found", 404) + return + } + if r.Method != "GET" { + http.Error(w, "Method not allowed", 405) + return + } + w.Header().Set("Content-Type", "text/html; charset=utf-8") + homeTempl.Execute(w, r.Host) +} + +func main() { + flag.Parse() + if len(flag.Args()) < 1 { + log.Fatal("must specify at least one argument") + } + var err error + cmdPath, err = exec.LookPath(flag.Args()[0]) + if err != nil { + log.Fatal(err) + } + http.HandleFunc("/", serveHome) + http.HandleFunc("/ws", serveWs) + log.Fatal(http.ListenAndServe(*addr, nil)) +} |