Added remote execution example

dmcgowan · dmcgowan · commit b3647bb7fb55 · 2014-08-07T16:13:41.000-07:00
Signed-off-by: Derek McGowan &lt;derek@mcgstyle.net&gt; (github: dmcgowan)
diff --git a/examples/rexec/README.md b/examples/rexec/README.md
@@ -0,0 +1,36 @@
+# rexec
+
+rexec is a sample application demonstrating libchan nested channels and
+bytestreams through remote executation calls.  This is a minimal
+implementation to demonstrate the usage of libchan.
+
+### Usage
+
+Server
+~~~~
+$ cd rexec_server
+$ go build .
+$ ./rexec_server
+~~~~
+
+Client
+~~~~
+$ go build .
+$ ./rexec /bin/echo "hello"
+hello
+$ ./rexec /bin/sh -c "exit 4"
+$ echo $?
+4
+~~~~
+
+### Usage with TLS
+Server
+~~~~
+$ TLS_CERT=./cert.pem TLS_KEY=./key.pem ./rexec_server
+~~~~
+
+Client
+~~~~
+$ USE_TLS=true ./rexec /bin/echo "hello"
+hello
+~~~~
diff --git a/examples/rexec/client.go b/examples/rexec/client.go
@@ -0,0 +1,75 @@
+package main
+
+import (
+	"crypto/tls"
+	"io"
+	"log"
+	"net"
+	"os"
+
+	"github.com/docker/libchan"
+	"github.com/docker/libchan/spdy"
+)
+
+type RemoteCommand struct {
+	Cmd        string
+	Args       []string
+	Stdin      io.Writer
+	Stdout     io.Reader
+	Stderr     io.Reader
+	StatusChan libchan.Sender
+}
+
+type CommandResponse struct {
+	Status int
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		log.Fatal("usage: <command> [<arg> ]")
+	}
+
+	var client net.Conn
+	var err error
+	if os.Getenv("USE_TLS") != "" {
+		client, err = tls.Dial("tcp", "127.0.0.1:9323", &tls.Config{InsecureSkipVerify: true})
+	} else {
+		client, err = net.Dial("tcp", "127.0.0.1:9323")
+	}
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	transport, err := spdy.NewClientTransport(client)
+	if err != nil {
+		log.Fatal(err)
+	}
+	sender, err := transport.NewSendChannel()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	receiver, remoteSender := libchan.Pipe()
+
+	command := &RemoteCommand{
+		Cmd:        os.Args[1],
+		Args:       os.Args[2:],
+		Stdin:      os.Stdin,
+		Stdout:     os.Stdout,
+		Stderr:     os.Stderr,
+		StatusChan: remoteSender,
+	}
+
+	err = sender.Send(command)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	response := &CommandResponse{}
+	err = receiver.Receive(response)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	os.Exit(response.Status)
+}
diff --git a/examples/rexec/rexec_server/cert.pem b/examples/rexec/rexec_server/cert.pem
@@ -0,0 +1,18 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/examples/rexec/rexec_server/key.pem b/examples/rexec/rexec_server/key.pem
@@ -0,0 +1,27 @@
+-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----
diff --git a/examples/rexec/rexec_server/server.go b/examples/rexec/rexec_server/server.go
@@ -0,0 +1,122 @@
+package main
+
+import (
+	"crypto/tls"
+	"io"
+	"log"
+	"net"
+	"os"
+	"os/exec"
+	"syscall"
+
+	"github.com/docker/libchan"
+	"github.com/docker/libchan/spdy"
+)
+
+type RemoteCommand struct {
+	Cmd        string
+	Args       []string
+	Stdin      io.Reader
+	Stdout     io.WriteCloser
+	Stderr     io.WriteCloser
+	StatusChan libchan.Sender
+}
+
+type CommandResponse struct {
+	Status int
+}
+
+func main() {
+	cert := os.Getenv("TLS_CERT")
+	key := os.Getenv("TLS_KEY")
+
+	var listener net.Listener
+	if cert != "" && key != "" {
+		tlsCert, err := tls.LoadX509KeyPair(cert, key)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		tlsConfig := &tls.Config{
+			InsecureSkipVerify: true,
+			Certificates:       []tls.Certificate{tlsCert},
+		}
+
+		listener, err = tls.Listen("tcp", "localhost:9323", tlsConfig)
+		if err != nil {
+			log.Fatal(err)
+		}
+	} else {
+		var err error
+		listener, err = net.Listen("tcp", "localhost:9323")
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	tl, err := spdy.NewTransportListener(listener, spdy.NoAuthenticator)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for {
+		t, err := tl.AcceptTransport()
+		if err != nil {
+			log.Print(err)
+			break
+		}
+
+		go func() {
+			for {
+				receiver, err := t.WaitReceiveChannel()
+				if err != nil {
+					log.Print(err)
+					break
+				}
+
+				go func() {
+					for {
+						command := &RemoteCommand{}
+						err := receiver.Receive(command)
+						if err != nil {
+							log.Print(err)
+							break
+						}
+
+						cmd := exec.Command(command.Cmd, command.Args...)
+						cmd.Stdout = command.Stdout
+						cmd.Stderr = command.Stderr
+
+						stdin, err := cmd.StdinPipe()
+						if err != nil {
+							log.Print(err)
+							break
+						}
+						go func() {
+							io.Copy(stdin, command.Stdin)
+							stdin.Close()
+						}()
+
+						res := cmd.Run()
+						command.Stdout.Close()
+						command.Stderr.Close()
+						returnResult := &CommandResponse{}
+						if res != nil {
+							if exiterr, ok := res.(*exec.ExitError); ok {
+								returnResult.Status = exiterr.Sys().(syscall.WaitStatus).ExitStatus()
+							} else {
+								log.Print(res)
+								returnResult.Status = 10
+							}
+						}
+
+						err = command.StatusChan.Send(returnResult)
+						if err != nil {
+							log.Print(err)
+						}
+					}
+				}()
+			}
+		}()
+	}
+}
