package client import ( "fmt" "io" "golang.org/x/net/context" "github.com/Sirupsen/logrus" Cli "github.com/docker/docker/cli" flag "github.com/docker/docker/pkg/mflag" "github.com/docker/docker/pkg/signal" "github.com/docker/engine-api/types" ) // CmdAttach attaches to a running container. // // Usage: docker attach [OPTIONS] CONTAINER func (cli *DockerCli) CmdAttach(args ...string) error { cmd := Cli.Subcmd("attach", []string{"CONTAINER"}, Cli.DockerCommands["attach"].Description, true) noStdin := cmd.Bool([]string{"-no-stdin"}, false, "Do not attach STDIN") proxy := cmd.Bool([]string{"-sig-proxy"}, true, "Proxy all received signals to the process") detachKeys := cmd.String([]string{"-detach-keys"}, "", "Override the key sequence for detaching a container") cmd.Require(flag.Exact, 1) cmd.ParseFlags(args, true) c, err := cli.client.ContainerInspect(context.Background(), cmd.Arg(0)) 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 := cli.CheckTtyInput(!*noStdin, c.Config.Tty); err != nil { return err } if *detachKeys != "" { cli.configFile.DetachKeys = *detachKeys } options := types.ContainerAttachOptions{ ContainerID: cmd.Arg(0), Stream: true, Stdin: !*noStdin && c.Config.OpenStdin, Stdout: true, Stderr: true, DetachKeys: cli.configFile.DetachKeys, } var in io.ReadCloser if options.Stdin { in = cli.in } if *proxy && !c.Config.Tty { sigc := cli.forwardAllSignals(options.ContainerID) defer signal.StopCatch(sigc) } resp, err := cli.client.ContainerAttach(context.Background(), options) if err != nil { return err } defer resp.Close() if c.Config.Tty && cli.isTerminalOut { height, width := cli.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. cli.resizeTtyTo(cmd.Arg(0), 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 := cli.monitorTtySize(cmd.Arg(0), false); err != nil { logrus.Debugf("Error monitoring TTY size: %s", err) } } if err := cli.holdHijackedConnection(context.Background(), c.Config.Tty, in, cli.out, cli.err, resp); err != nil { return err } _, status, err := getExitCode(cli, options.ContainerID) if err != nil { return err } if status != 0 { return Cli.StatusError{StatusCode: status} } return nil }