Add flag to sync extensions back to local

Resolves #20

.sail/Dockerfile

@@ -1,3 +1,6 @@
 FROM codercom/ubuntu-dev-go
 
+# Go module tooling is completely broken.
+ENV GO111MODULE=off
+
 LABEL project_root "~/go/src/go.coder.com"

README.md

@@ -50,3 +50,9 @@ This operation may take a while on a slow connections, but will be fast
 on follow-up connections to the same server.
 
 To disable this feature entirely, pass the `--skipsync` flag.
+
+### Sync-back
+
+By default, VS Code changes on the remote server won't be synced back
+when the connection closes. To synchronize back to local when the connection ends,
+pass the `-b` flag.

main.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"os"
 	"os/exec"
+	"os/signal"
 	"path/filepath"
 	"runtime"
 	"strconv"
@@ -24,8 +25,12 @@ func init() {
 }
 
 func main() {
-	skipSyncFlag := flag.Bool("skipsync", false, "skip syncing local settings and extensions to remote host")
-	sshFlags := flag.String("ssh-flags", "", "custom SSH flags")
+	var (
+		skipSyncFlag = flag.Bool("skipsync", false, "skip syncing local settings and extensions to remote host")
+		sshFlags     = flag.String("ssh-flags", "", "custom SSH flags")
+		syncBack     = flag.Bool("b", false, "sync extensions back on termination")
+	)
+
 	flag.Usage = func() {
 		fmt.Printf(`Usage: [-skipsync] %v HOST [DIR] [SSH ARGS...]
 
@@ -58,6 +63,9 @@ More info: https://github.com/codercom/sshcode
 		"-tt",
 		host,
 		`/bin/bash -c 'set -euxo pipefail || exit 1
+# Make sure any currently running code-server is gone so we can overwrite
+# the binary.
+pkill -9 `+filepath.Base(codeServerPath)+` || true
 wget -q https://codesrv-ci.cdr.sh/latest-linux -O `+codeServerPath+`
 mkdir -p ~/.local/share/code-server
 cd `+filepath.Dir(codeServerPath)+`
@@ -74,17 +82,17 @@ chmod +x `+codeServerPath+`
 		flog.Fatal("failed to update code-server: %v", err)
 	}
 
-	if !(*skipSyncFlag) {
+	if !*skipSyncFlag {
 		start := time.Now()
 		flog.Info("syncing settings")
-		err = syncUserSettings(host)
+		err = syncUserSettings(host, false)
 		if err != nil {
 			flog.Fatal("failed to sync settings: %v", err)
 		}
 		flog.Info("synced settings in %s", time.Since(start))
 
 		flog.Info("syncing extensions")
-		err = syncExtensions(host)
+		err = syncExtensions(host, false)
 		if err != nil {
 			flog.Fatal("failed to sync extensions: %v", err)
 		}
@@ -131,8 +139,38 @@ chmod +x `+codeServerPath+`
 		break
 	}
 
+	ctx, cancel = context.WithCancel(context.Background())
 	openBrowser(url)
-	sshCmd.Wait()
+
+	go func() {
+		defer cancel()
+		sshCmd.Wait()
+	}()
+
+	c := make(chan os.Signal)
+	signal.Notify(c, os.Interrupt)
+
+	select {
+	case <-ctx.Done():
+	case <-c:
+	}
+
+	if !*syncBack {
+		flog.Info("shutting down")
+		return
+	}
+
+	flog.Info("synchronizing VS Code back to local")
+
+	err = syncExtensions(host, true)
+	if err != nil {
+		flog.Fatal("failed to sync extensions back: %v", err)
+	}
+
+	err = syncUserSettings(host, true)
+	if err != nil {
+		flog.Fatal("failed to user settigns extensions back: %v", err)
+	}
 }
 
 func openBrowser(url string) {
@@ -197,40 +235,63 @@ func randomPort() (string, error) {
 	return "", xerrors.Errorf("max number of tries exceeded: %d", maxTries)
 }
 
-func syncUserSettings(host string) error {
+func syncUserSettings(host string, back bool) error {
 	localConfDir, err := configDir()
 	if err != nil {
 		return err
 	}
-	const remoteSettingsDir = ".local/share/code-server/User"
+	const remoteSettingsDir = ".local/share/code-server/User/"
+
+	var (
+		src  = localConfDir + "/"
+		dest = host + ":" + remoteSettingsDir
+	)
+
+	if back {
+		dest, src = src, dest
+	}
 
 	// Append "/" to have rsync copy the contents of the dir.
-	return rsync(localConfDir+"/", remoteSettingsDir, host, "workspaceStorage", "logs", "CachedData")
+	return rsync(src, dest, "workspaceStorage", "logs", "CachedData")
 }
 
-func syncExtensions(host string) error {
+func syncExtensions(host string, back bool) error {
 	localExtensionsDir, err := extensionsDir()
 	if err != nil {
 		return err
 	}
-	const remoteExtensionsDir = ".local/share/code-server/extensions"
+	const remoteExtensionsDir = ".local/share/code-server/extensions/"
+
+	var (
+		src  = localExtensionsDir + "/"
+		dest = host + ":" + remoteExtensionsDir
+	)
+	if back {
+		dest, src = src, dest
+	}
 
-	return rsync(localExtensionsDir+"/", remoteExtensionsDir, host)
+	return rsync(src, dest)
 }
 
-func rsync(src string, dest string, host string, excludePaths ...string) error {
-	remoteDest := fmt.Sprintf("%s:%s", host, dest)
+func rsync(src string, dest string, excludePaths ...string) error {
 	excludeFlags := make([]string, len(excludePaths))
 	for i, path := range excludePaths {
 		excludeFlags[i] = "--exclude=" + path
 	}
 
-	cmd := exec.Command("rsync", append(excludeFlags, "-azv", "--copy-unsafe-links", src, remoteDest)...)
+	cmd := exec.Command("rsync", append(excludeFlags, "-azvr",
+		// Only update newer directories, and sync times
+		// to keep things simple.
+		"-u", "--times",
+		"--copy-unsafe-links",
+		src, dest,
+	)...,
+	)
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
 	err := cmd.Run()
 	if err != nil {
-		return xerrors.Errorf("failed to rsync '%s' to '%s': %w", src, remoteDest, err)
+		return xerrors.Errorf("failed to rsync '%s' to '%s': %w", src, dest, err)
 	}
 
 	return nil
@@ -240,9 +301,9 @@ func configDir() (string, error) {
 	var path string
 	switch runtime.GOOS {
 	case "linux":
-		path = os.ExpandEnv("$HOME/.config/Code/User")
+		path = os.ExpandEnv("$HOME/.config/Code/User/")
 	case "darwin":
-		path = os.ExpandEnv("$HOME/Library/Application Support/Code/User")
+		path = os.ExpandEnv("$HOME/Library/Application Support/Code/User/")
 	default:
 		return "", xerrors.Errorf("unsupported platform: %s", runtime.GOOS)
 	}
@@ -253,7 +314,7 @@ func extensionsDir() (string, error) {
 	var path string
 	switch runtime.GOOS {
 	case "linux", "darwin":
-		path = os.ExpandEnv("$HOME/.vscode/extensions")
+		path = os.ExpandEnv("$HOME/.vscode/extensions/")
 	default:
 		return "", xerrors.Errorf("unsupported platform: %s", runtime.GOOS)
 	}