From a790f8ee891bfcad4e541280d36d0e5f711430ac Mon Sep 17 00:00:00 2001
From: Christian Schwarz <me@cschwarz.com>
Date: Sat, 15 Apr 2017 15:43:50 +0200
Subject: [PATCH] Implement ssh-based byte stream transport.

---
 sshbytestream/ssh.go | 104 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 93 insertions(+), 11 deletions(-)

diff --git a/sshbytestream/ssh.go b/sshbytestream/ssh.go
index b1b15f4..6238218 100644
--- a/sshbytestream/ssh.go
+++ b/sshbytestream/ssh.go
@@ -1,28 +1,110 @@
 package sshbytestream
 
-func Incoming() (io.ReadWriteCloser, error) {
+import (
+	"io"
+	"os"
+	"os/exec"
+	"github.com/zrepl/zrepl/model"
+	"context"
+	"fmt"
+	"bytes"
+	"sync"
+)
+
+var SSHCommand string = "ssh"
+
+func Incoming() (wc io.ReadWriteCloser, err error) {
 	// derivce ReadWriteCloser from stdin & stdout
+	return IncomingReadWriteCloser{}, nil
 }
 
-func Outgoing(name string, remote model.SSHTransport) (io.ReadWriteCloser, error) {
-	// encapsulate
-	//  fork(),exec(ssh $remote zrepl ipc ssh $name)
-	// stdin and stdout in a ReadWriteCloser
-	return ForkedSSHReadWriteCloser{}
+type IncomingReadWriteCloser struct{}
+
+func (f IncomingReadWriteCloser) Read(p []byte) (n int, err error) {
+	return os.Stdin.Read(p)
 }
 
-struct ForkedSSHReadWriteCloser {
+func (f IncomingReadWriteCloser) Write(p []byte) (n int, err error) {
+	return os.Stdout.Write(p)
+}
 
+func (f IncomingReadWriteCloser)  Close() (err error) {
+	os.Exit(0)
+	return nil
+}
+
+func Outgoing(name string, remote model.SSHTransport) (conn io.ReadWriteCloser, err error) {
+
+	ctx, cancel := context.WithCancel(context.Background())
+
+	sshArgs := make([]string, 0, 2 * len(remote.Options) + len(remote.TransportOpenCommand) + 4)
+	sshArgs = append(sshArgs,
+		"-p", fmt.Sprintf("%d", remote.Port),
+		"-o", "BatchMode=yes",
+	)
+	for _,option := range remote.Options {
+		sshArgs = append(sshArgs, "-o", option)
+	}
+	sshArgs = append(sshArgs, fmt.Sprintf("%s@%s", remote.User, remote.Host))
+	sshArgs = append(sshArgs, remote.TransportOpenCommand...)
+
+	cmd := exec.CommandContext(ctx, SSHCommand, sshArgs...)
+
+	var in io.WriteCloser
+	var out io.ReadCloser
+
+	if in, err = cmd.StdinPipe(); err != nil {
+		return
+	}
+
+	if out,err = cmd.StdoutPipe(); err != nil {
+		return
+	}
+
+
+	f := ForkedSSHReadWriteCloser{
+		RemoteStdin: in,
+		RemoteStdout: out,
+		Cancel: cancel,
+		Command: cmd,
+		exitWaitGroup: &sync.WaitGroup{},
+	}
+
+	f.exitWaitGroup.Add(1)
+
+	go func() {
+		defer f.exitWaitGroup.Done()
+		stderr, _ := cmd.StderrPipe()
+		var b bytes.Buffer
+		if err := cmd.Run(); err != nil {
+			io.Copy(&b, stderr)
+			fmt.Println(b.String())
+			fmt.Printf("%v\n", cmd.ProcessState)
+			panic(err)
+		}
+	}()
+
+	return f, nil
+}
+
+type  ForkedSSHReadWriteCloser struct {
+	RemoteStdin io.Writer
+	RemoteStdout io.Reader
+	Command *exec.Cmd
+	Cancel 	context.CancelFunc
+	exitWaitGroup *sync.WaitGroup
 }
 
 func (f ForkedSSHReadWriteCloser) Read(p []byte) (n int, err error) {
-
+	return f.RemoteStdout.Read(p)
 }
 
 func (f ForkedSSHReadWriteCloser) Write(p []byte) (n int, err error) {
-
+	return f.RemoteStdin.Write(p)
 }
 
-func (f ForkedSSHReadWriteCloser)  Close() error {
-
+func (f ForkedSSHReadWriteCloser)  Close() (err error) {
+	f.Cancel()
+	f.exitWaitGroup.Wait()
+	return nil
 }
\ No newline at end of file