func runAttach(dockerCli *client.DockerCli, opts *attachOptions) error {
ctx := context.Background()
c, err := dockerCli.Client().ContainerInspect(ctx, opts.container)
if err != nil {
return err
}
if !c.State.Running {
return fmt.Errorf("You cannot attach to a stopped container, start it first")
}
if c.State.Paused {
return fmt.Errorf("You cannot attach to a paused container, unpause it first")
}
if err := dockerCli.CheckTtyInput(!opts.noStdin, c.Config.Tty); err != nil {
return err
}
if opts.detachKeys != "" {
dockerCli.ConfigFile().DetachKeys = opts.detachKeys
}
options := types.ContainerAttachOptions{
Stream: true,
Stdin: !opts.noStdin && c.Config.OpenStdin,
Stdout: true,
Stderr: true,
DetachKeys: dockerCli.ConfigFile().DetachKeys,
}
var in io.ReadCloser
if options.Stdin {
in = dockerCli.In()
}
if opts.proxy && !c.Config.Tty {
sigc := dockerCli.ForwardAllSignals(ctx, opts.container)
defer signal.StopCatch(sigc)
}
resp, errAttach := dockerCli.Client().ContainerAttach(ctx, opts.container, options)
if errAttach != nil && errAttach != httputil.ErrPersistEOF {
// ContainerAttach returns an ErrPersistEOF (connection closed)
// means server met an error and put it in Hijacked connection
// keep the error and read detailed error message from hijacked connection later
return errAttach
}
defer resp.Close()
if c.Config.Tty && dockerCli.IsTerminalOut() {
height, width := dockerCli.GetTtySize()
// To handle the case where a user repeatedly attaches/detaches without resizing their
// terminal, the only way to get the shell prompt to display for attaches 2+ is to artificially
// resize it, then go back to normal. Without this, every attach after the first will
// require the user to manually resize or hit enter.
dockerCli.ResizeTtyTo(ctx, opts.container, height+1, width+1, false)
// After the above resizing occurs, the call to MonitorTtySize below will handle resetting back
// to the actual size.
if err := dockerCli.MonitorTtySize(ctx, opts.container, false); err != nil {
logrus.Debugf("Error monitoring TTY size: %s", err)
}
}
if err := dockerCli.HoldHijackedConnection(ctx, c.Config.Tty, in, dockerCli.Out(), dockerCli.Err(), resp); err != nil {
return err
}
if errAttach != nil {
return errAttach
}
_, status, err := getExitCode(dockerCli, ctx, opts.container)
if err != nil {
return err
}
if status != 0 {
return cli.StatusError{StatusCode: status}
}
return nil
}