cli/cmd/ghcs/ssh.go
2021-09-21 17:38:41 +02:00

110 lines
3.1 KiB
Go

package ghcs
import (
"context"
"fmt"
"net"
"os"
"github.com/github/ghcs/cmd/ghcs/output"
"github.com/github/ghcs/internal/api"
"github.com/github/ghcs/internal/codespaces"
"github.com/github/go-liveshare"
"github.com/spf13/cobra"
)
func newSSHCmd() *cobra.Command {
var sshProfile, codespaceName string
var sshServerPort int
sshCmd := &cobra.Command{
Use: "ssh [flags] [--] [ssh-flags] [command]",
Short: "SSH into a codespace",
RunE: func(cmd *cobra.Command, args []string) error {
return ssh(context.Background(), args, sshProfile, codespaceName, sshServerPort)
},
}
sshCmd.Flags().StringVarP(&sshProfile, "profile", "", "", "Name of the SSH profile to use")
sshCmd.Flags().IntVarP(&sshServerPort, "server-port", "", 0, "SSH server port number (0 => pick unused)")
sshCmd.Flags().StringVarP(&codespaceName, "codespace", "c", "", "Name of the codespace")
return sshCmd
}
func ssh(ctx context.Context, sshArgs []string, sshProfile, codespaceName string, localSSHServerPort int) (err error) {
// Ensure all child tasks (e.g. port forwarding) terminate before return.
ctx, cancel := context.WithCancel(ctx)
defer cancel()
apiClient := api.New(GithubToken)
log := output.NewLogger(os.Stdout, os.Stderr, false)
user, err := apiClient.GetUser(ctx)
if err != nil {
return fmt.Errorf("error getting user: %w", err)
}
authkeys := make(chan error, 1)
go func() {
authkeys <- checkAuthorizedKeys(ctx, apiClient, user.Login)
}()
codespace, token, err := getOrChooseCodespace(ctx, apiClient, user, codespaceName)
if err != nil {
return fmt.Errorf("get or choose codespace: %w", err)
}
session, err := codespaces.ConnectToLiveshare(ctx, log, apiClient, user.Login, token, codespace)
if err != nil {
return fmt.Errorf("error connecting to Live Share: %w", err)
}
defer safeClose(session, &err)
if err := <-authkeys; err != nil {
return err
}
log.Println("Fetching SSH Details...")
remoteSSHServerPort, sshUser, err := session.StartSSHServer(ctx)
if err != nil {
return fmt.Errorf("error getting ssh server details: %w", err)
}
usingCustomPort := localSSHServerPort != 0 // suppress log of command line in Shell
// Ensure local port is listening before client (Shell) connects.
listen, err := net.Listen("tcp", fmt.Sprintf(":%d", localSSHServerPort))
if err != nil {
return err
}
defer listen.Close()
localSSHServerPort = listen.Addr().(*net.TCPAddr).Port
connectDestination := sshProfile
if connectDestination == "" {
connectDestination = fmt.Sprintf("%s@localhost", sshUser)
}
log.Println("Ready...")
tunnelClosed := make(chan error, 1)
go func() {
fwd := liveshare.NewPortForwarder(session, "sshd", remoteSSHServerPort)
tunnelClosed <- fwd.ForwardToListener(ctx, listen) // always non-nil
}()
shellClosed := make(chan error, 1)
go func() {
shellClosed <- codespaces.Shell(ctx, log, sshArgs, localSSHServerPort, connectDestination, usingCustomPort)
}()
select {
case err := <-tunnelClosed:
return fmt.Errorf("tunnel closed: %w", err)
case err := <-shellClosed:
if err != nil {
return fmt.Errorf("shell closed: %w", err)
}
return nil // success
}
}