At present I want to connect container stdin and stdout with websocket. But I can not read stdout if there are no output. e.g. "cd /"
Here is my code:
package main
import (
dcl "github.com/docker/docker/client"
"context"
"html/template"
"github.com/docker/docker/api/types"
"log"
"net/http"
"flag"
"github.com/gorilla/websocket"
"fmt"
"io"
"bufio"
)
var inout chan []byte
var output chan []byte
var addr = flag.String("addr", "localhost:8080", "http service address")
var upgrader = websocket.Upgrader{}
func echo(w http.ResponseWriter, r *http.Request) {
conn, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Print(err)
return
}
defer conn.Close()
cli, err := dcl.NewEnvClient()
if err != nil {
log.Print(err)
conn.WriteMessage(websocket.TextMessage, []byte(err.Error()))
return
}
ctx := context.Background()
execConfig := types.ExecConfig{
AttachStderr: true,
AttachStdin: true,
AttachStdout: true,
Cmd: []string{"/bin/sh"},
Tty: false,
Detach: false,
}
//set target container
exec, err := cli.ContainerExecCreate(ctx, "ubuntu", execConfig)
if err != nil {
log.Print(err)
conn.WriteMessage(websocket.TextMessage, []byte(err.Error()))
return
}
execAttachConfig := types.ExecStartCheck{
Detach: false,
Tty: false,
}
containerConn, err := cli.ContainerExecAttach(ctx, exec.ID, execAttachConfig)
if err != nil {
log.Print(err)
conn.WriteMessage(websocket.TextMessage, []byte(err.Error()))
return
}
defer containerConn.Close()
bufin := bufio.NewReader(containerConn.Reader)
go func(w io.WriteCloser) {
for {
data, ok := <-inout
if !ok {
fmt.Println("!ok")
w.Close()
return
}
fmt.Println(string(data))
w.Write(append(data, '
'))
}
}(containerConn.Conn)
go func() {
for {
buffer := make([]byte, 4096, 4096)
c, err := bufin.Read(buffer)
if err != nil{
fmt.Println(err)
}
//c, err := containerConn.Reader.Read(buffer)
if c > 0 {
output <- buffer[:c]
}
if c == 0{
output <- []byte{' '}
}
if err != nil {
break
}
}
}()
for {
mt, message, err := conn.ReadMessage()
if err != nil {
log.Println("read:", err)
break
}
log.Printf("recv: %s", message)
inout <- message
data := <-output
err = conn.WriteMessage(mt, data)
if err != nil {
log.Println("write:", err)
break
}
}
}
func home(w http.ResponseWriter, r *http.Request) {
homeTemplate.Execute(w, "ws://"+r.Host+"/echo")
}
func main() {
inout = make(chan []byte)
output = make(chan []byte)
http.HandleFunc("/echo", echo)
http.HandleFunc("/", home)
log.Fatal(http.ListenAndServe(*addr, nil))
}
var homeTemplate = template.Must(template.New("").Parse(`
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script>
window.addEventListener("load", function(evt) {
var output = document.getElementById("output");
var input = document.getElementById("input");
var ws;
var print = function(message) {
var d = document.createElement("div");
d.innerHTML = message;
output.appendChild(d);
};
document.getElementById("open").onclick = function(evt) {
if (ws) {
return false;
}
ws = new WebSocket("{{.}}");
ws.onopen = function(evt) {
print("OPEN");
}
ws.onclose = function(evt) {
print("CLOSE");
ws = null;
}
ws.onmessage = function(evt) {
print("RESPONSE: " + evt.data);
}
ws.onerror = function(evt) {
print("ERROR: " + evt.data);
}
return false;
};
document.getElementById("send").onclick = function(evt) {
if (!ws) {
return false;
}
print("SEND: " + input.value);
ws.send(input.value);
return false;
};
document.getElementById("close").onclick = function(evt) {
if (!ws) {
return false;
}
ws.close();
return false;
};
});
</script>
</head>
<body>
<table>
<tr><td valign="top" width="50%">
<p>Click "Open" to create a connection to the server,
"Send" to send a message to the server and "Close" to close the connection.
You can change the message and send multiple times.
<p>
<form>
<button id="open">Open</button>
<button id="close">Close</button>
<p><input id="input" type="text" value="ls">
<button id="send">Send</button>
</form>
</td><td valign="top" width="50%">
<div id="output"></div>
</td></tr></table>
</body>
</html>
`))
I try many ways, but no way can work :(
