coder/cli/ssh.go

361 lines
11 KiB
Go

package cli
import (
"context"
"errors"
"fmt"
"io"
"os"
"path/filepath"
"strings"
"time"
"github.com/gen2brain/beeep"
"github.com/gofrs/flock"
"github.com/google/uuid"
"github.com/mattn/go-isatty"
"github.com/spf13/cobra"
gossh "golang.org/x/crypto/ssh"
gosshagent "golang.org/x/crypto/ssh/agent"
"golang.org/x/term"
"golang.org/x/xerrors"
"cdr.dev/slog"
"github.com/coder/coder/agent"
"github.com/coder/coder/cli/cliflag"
"github.com/coder/coder/cli/cliui"
"github.com/coder/coder/coderd/autobuild/notify"
"github.com/coder/coder/coderd/util/ptr"
"github.com/coder/coder/codersdk"
"github.com/coder/coder/cryptorand"
)
var (
workspacePollInterval = time.Minute
autostopNotifyCountdown = []time.Duration{30 * time.Minute}
)
func ssh() *cobra.Command {
var (
stdio bool
shuffle bool
forwardAgent bool
identityAgent string
wsPollInterval time.Duration
wireguard bool
)
cmd := &cobra.Command{
Annotations: workspaceCommand,
Use: "ssh <workspace>",
Short: "SSH into a workspace",
Args: cobra.ArbitraryArgs,
RunE: func(cmd *cobra.Command, args []string) error {
ctx, cancel := context.WithCancel(cmd.Context())
defer cancel()
client, err := CreateClient(cmd)
if err != nil {
return err
}
if shuffle {
err := cobra.ExactArgs(0)(cmd, args)
if err != nil {
return err
}
} else {
err := cobra.MinimumNArgs(1)(cmd, args)
if err != nil {
return err
}
}
workspace, workspaceAgent, err := getWorkspaceAndAgent(ctx, cmd, client, codersdk.Me, args[0], shuffle)
if err != nil {
return err
}
// OpenSSH passes stderr directly to the calling TTY.
// This is required in "stdio" mode so a connecting indicator can be displayed.
err = cliui.Agent(ctx, cmd.ErrOrStderr(), cliui.AgentOptions{
WorkspaceName: workspace.Name,
Fetch: func(ctx context.Context) (codersdk.WorkspaceAgent, error) {
return client.WorkspaceAgent(ctx, workspaceAgent.ID)
},
})
if err != nil {
return xerrors.Errorf("await agent: %w", err)
}
var conn agent.Conn
if !wireguard {
conn, err = client.DialWorkspaceAgent(ctx, workspaceAgent.ID, nil)
} else {
conn, err = client.DialWorkspaceAgentTailnet(ctx, slog.Logger{}, workspaceAgent.ID)
}
if err != nil {
return err
}
defer conn.Close()
stopPolling := tryPollWorkspaceAutostop(ctx, client, workspace)
defer stopPolling()
if stdio {
rawSSH, err := conn.SSH()
if err != nil {
return err
}
defer rawSSH.Close()
go func() {
_, _ = io.Copy(cmd.OutOrStdout(), rawSSH)
}()
_, _ = io.Copy(rawSSH, cmd.InOrStdin())
return nil
}
sshClient, err := conn.SSHClient()
if err != nil {
return err
}
defer sshClient.Close()
sshSession, err := sshClient.NewSession()
if err != nil {
return err
}
defer sshSession.Close()
// Ensure context cancellation is propagated to the
// SSH session, e.g. to cancel `Wait()` at the end.
go func() {
<-ctx.Done()
_ = sshSession.Close()
}()
if identityAgent == "" {
identityAgent = os.Getenv("SSH_AUTH_SOCK")
}
if forwardAgent && identityAgent != "" {
err = gosshagent.ForwardToRemote(sshClient, identityAgent)
if err != nil {
return xerrors.Errorf("forward agent failed: %w", err)
}
err = gosshagent.RequestAgentForwarding(sshSession)
if err != nil {
return xerrors.Errorf("request agent forwarding failed: %w", err)
}
}
stdoutFile, validOut := cmd.OutOrStdout().(*os.File)
stdinFile, validIn := cmd.InOrStdin().(*os.File)
if validOut && validIn && isatty.IsTerminal(stdoutFile.Fd()) {
state, err := term.MakeRaw(int(stdinFile.Fd()))
if err != nil {
return err
}
defer func() {
_ = term.Restore(int(stdinFile.Fd()), state)
}()
windowChange := listenWindowSize(ctx)
go func() {
for {
select {
case <-ctx.Done():
return
case <-windowChange:
}
width, height, err := term.GetSize(int(stdoutFile.Fd()))
if err != nil {
continue
}
_ = sshSession.WindowChange(height, width)
}
}()
}
err = sshSession.RequestPty("xterm-256color", 128, 128, gossh.TerminalModes{})
if err != nil {
return err
}
sshSession.Stdin = cmd.InOrStdin()
sshSession.Stdout = cmd.OutOrStdout()
sshSession.Stderr = cmd.ErrOrStderr()
err = sshSession.Shell()
if err != nil {
return err
}
// Put cancel at the top of the defer stack to initiate
// shutdown of services.
defer cancel()
if validOut {
// Set initial window size.
width, height, err := term.GetSize(int(stdoutFile.Fd()))
if err == nil {
_ = sshSession.WindowChange(height, width)
}
}
err = sshSession.Wait()
if err != nil {
// If the connection drops unexpectedly, we get an ExitMissingError but no other
// error details, so try to at least give the user a better message
if errors.Is(err, &gossh.ExitMissingError{}) {
return xerrors.New("SSH connection ended unexpectedly")
}
return err
}
return nil
},
}
cliflag.BoolVarP(cmd.Flags(), &stdio, "stdio", "", "CODER_SSH_STDIO", false, "Specifies whether to emit SSH output over stdin/stdout.")
cliflag.BoolVarP(cmd.Flags(), &shuffle, "shuffle", "", "CODER_SSH_SHUFFLE", false, "Specifies whether to choose a random workspace")
_ = cmd.Flags().MarkHidden("shuffle")
cliflag.BoolVarP(cmd.Flags(), &forwardAgent, "forward-agent", "A", "CODER_SSH_FORWARD_AGENT", false, "Specifies whether to forward the SSH agent specified in $SSH_AUTH_SOCK")
cliflag.StringVarP(cmd.Flags(), &identityAgent, "identity-agent", "", "CODER_SSH_IDENTITY_AGENT", "", "Specifies which identity agent to use (overrides $SSH_AUTH_SOCK), forward agent must also be enabled")
cliflag.DurationVarP(cmd.Flags(), &wsPollInterval, "workspace-poll-interval", "", "CODER_WORKSPACE_POLL_INTERVAL", workspacePollInterval, "Specifies how often to poll for workspace automated shutdown.")
cliflag.BoolVarP(cmd.Flags(), &wireguard, "wireguard", "", "CODER_SSH_WIREGUARD", false, "Whether to use Wireguard for SSH tunneling.")
_ = cmd.Flags().MarkHidden("wireguard")
return cmd
}
// getWorkspaceAgent returns the workspace and agent selected using either the
// `<workspace>[.<agent>]` syntax via `in` or picks a random workspace and agent
// if `shuffle` is true.
func getWorkspaceAndAgent(ctx context.Context, cmd *cobra.Command, client *codersdk.Client, userID string, in string, shuffle bool) (codersdk.Workspace, codersdk.WorkspaceAgent, error) { //nolint:revive
var (
workspace codersdk.Workspace
workspaceParts = strings.Split(in, ".")
err error
)
if shuffle {
workspaces, err := client.Workspaces(ctx, codersdk.WorkspaceFilter{
Owner: codersdk.Me,
})
if err != nil {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, err
}
if len(workspaces) == 0 {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, xerrors.New("no workspaces to shuffle")
}
workspace, err = cryptorand.Element(workspaces)
if err != nil {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, err
}
} else {
workspace, err = namedWorkspace(cmd, client, workspaceParts[0])
if err != nil {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, err
}
}
if workspace.LatestBuild.Transition != codersdk.WorkspaceTransitionStart {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, xerrors.New("workspace must be in start transition to ssh")
}
if workspace.LatestBuild.Job.CompletedAt == nil {
err := cliui.WorkspaceBuild(ctx, cmd.ErrOrStderr(), client, workspace.LatestBuild.ID, workspace.CreatedAt)
if err != nil {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, err
}
}
if workspace.LatestBuild.Transition == codersdk.WorkspaceTransitionDelete {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, xerrors.Errorf("workspace %q is being deleted", workspace.Name)
}
resources, err := client.WorkspaceResourcesByBuild(ctx, workspace.LatestBuild.ID)
if err != nil {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, xerrors.Errorf("fetch workspace resources: %w", err)
}
agents := make([]codersdk.WorkspaceAgent, 0)
for _, resource := range resources {
agents = append(agents, resource.Agents...)
}
if len(agents) == 0 {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, xerrors.Errorf("workspace %q has no agents", workspace.Name)
}
var workspaceAgent codersdk.WorkspaceAgent
if len(workspaceParts) >= 2 {
for _, otherAgent := range agents {
if otherAgent.Name != workspaceParts[1] {
continue
}
workspaceAgent = otherAgent
break
}
if workspaceAgent.ID == uuid.Nil {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, xerrors.Errorf("agent not found by name %q", workspaceParts[1])
}
}
if workspaceAgent.ID == uuid.Nil {
if len(agents) > 1 {
if !shuffle {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, xerrors.New("you must specify the name of an agent")
}
workspaceAgent, err = cryptorand.Element(agents)
if err != nil {
return codersdk.Workspace{}, codersdk.WorkspaceAgent{}, err
}
} else {
workspaceAgent = agents[0]
}
}
return workspace, workspaceAgent, nil
}
// Attempt to poll workspace autostop. We write a per-workspace lockfile to
// avoid spamming the user with notifications in case of multiple instances
// of the CLI running simultaneously.
func tryPollWorkspaceAutostop(ctx context.Context, client *codersdk.Client, workspace codersdk.Workspace) (stop func()) {
lock := flock.New(filepath.Join(os.TempDir(), "coder-autostop-notify-"+workspace.ID.String()))
condition := notifyCondition(ctx, client, workspace.ID, lock)
return notify.Notify(condition, workspacePollInterval, autostopNotifyCountdown...)
}
// Notify the user if the workspace is due to shutdown.
func notifyCondition(ctx context.Context, client *codersdk.Client, workspaceID uuid.UUID, lock *flock.Flock) notify.Condition {
return func(now time.Time) (deadline time.Time, callback func()) {
// Keep trying to regain the lock.
locked, err := lock.TryLockContext(ctx, workspacePollInterval)
if err != nil || !locked {
return time.Time{}, nil
}
ws, err := client.Workspace(ctx, workspaceID)
if err != nil {
return time.Time{}, nil
}
if ptr.NilOrZero(ws.TTLMillis) {
return time.Time{}, nil
}
deadline = ws.LatestBuild.Deadline.Time
callback = func() {
ttl := deadline.Sub(now)
var title, body string
if ttl > time.Minute {
title = fmt.Sprintf(`Workspace %s stopping soon`, ws.Name)
body = fmt.Sprintf(
`Your Coder workspace %s is scheduled to stop in %.0f mins`, ws.Name, ttl.Minutes())
} else {
title = fmt.Sprintf("Workspace %s stopping!", ws.Name)
body = fmt.Sprintf("Your Coder workspace %s is stopping any time now!", ws.Name)
}
// notify user with a native system notification (best effort)
_ = beeep.Notify(title, body, "")
}
return deadline.Truncate(time.Minute), callback
}
}