cli/internal/codespaces/ssh.go

76 lines
2.3 KiB
Go

package codespaces
import (
"context"
"errors"
"fmt"
"os"
"os/exec"
"strconv"
"strings"
"github.com/github/go-liveshare"
)
// StartSSHServer installs (if necessary) and starts the SSH in the codespace.
// It returns the remote port where it is running, the user to log in with, or an error if something failed.
func StartSSHServer(ctx context.Context, session *liveshare.Session, log logger) (serverPort int, user string, err error) {
log.Println("Fetching SSH details...")
sshServer := session.SSHServer()
sshServerStartResult, err := sshServer.StartRemoteServer(ctx)
if err != nil {
return 0, "", fmt.Errorf("error starting live share: %v", err)
}
if !sshServerStartResult.Result {
return 0, "", errors.New(sshServerStartResult.Message)
}
portInt, err := strconv.Atoi(sshServerStartResult.ServerPort)
if err != nil {
return 0, "", fmt.Errorf("error parsing port: %v", err)
}
return portInt, sshServerStartResult.User, nil
}
// Shell runs an interactive secure shell over an existing
// port-forwarding session. It runs until the shell is terminated
// (including by cancellation of the context).
func Shell(ctx context.Context, log logger, port int, destination string, usingCustomPort bool) error {
cmd, connArgs := newSSHCommand(ctx, port, destination, "")
if usingCustomPort {
log.Println("Connection Details: ssh " + destination + " " + strings.Join(connArgs, " "))
}
return cmd.Run()
}
// NewRemoteCommand returns an exec.Cmd that will securely run a shell
// command on the remote machine.
func NewRemoteCommand(ctx context.Context, tunnelPort int, destination, command string) *exec.Cmd {
cmd, _ := newSSHCommand(ctx, tunnelPort, destination, command)
return cmd
}
// newSSHCommand populates an exec.Cmd to run a command (or if blank,
// an interactive shell) over ssh.
func newSSHCommand(ctx context.Context, port int, dst, command string) (*exec.Cmd, []string) {
connArgs := []string{"-p", strconv.Itoa(port), "-o", "NoHostAuthenticationForLocalhost=yes"}
// TODO(adonovan): eliminate X11 and X11Trust flags where unneeded.
cmdArgs := append([]string{dst, "-X", "-Y", "-C"}, connArgs...) // X11, X11Trust, Compression
if command != "" {
cmdArgs = append(cmdArgs, command)
}
cmd := exec.CommandContext(ctx, "ssh", cmdArgs...)
cmd.Stdout = os.Stdout
cmd.Stdin = os.Stdin
cmd.Stderr = os.Stderr
return cmd, connArgs
}