package daemon import ( "context" "fmt" "io" "github.com/docker/docker/api/types/backend" "github.com/docker/docker/container" "github.com/docker/docker/container/stream" "github.com/docker/docker/daemon/logger" "github.com/docker/docker/pkg/stdcopy" "github.com/docker/docker/pkg/term" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) // ContainerAttach attaches to logs according to the config passed in. See ContainerAttachConfig. func (daemon *Daemon) ContainerAttach(prefixOrName string, c *backend.ContainerAttachConfig) error { keys := []byte{} var err error if c.DetachKeys != "" { keys, err = term.ToBytes(c.DetachKeys) if err != nil { return validationError{errors.Errorf("Invalid detach keys (%s) provided", c.DetachKeys)} } } container, err := daemon.GetContainer(prefixOrName) if err != nil { return err } if container.IsPaused() { err := fmt.Errorf("container %s is paused, unpause the container before attach", prefixOrName) return stateConflictError{err} } if container.IsRestarting() { err := fmt.Errorf("container %s is restarting, wait until the container is running", prefixOrName) return stateConflictError{err} } cfg := stream.AttachConfig{ UseStdin: c.UseStdin, UseStdout: c.UseStdout, UseStderr: c.UseStderr, TTY: container.Config.Tty, CloseStdin: container.Config.StdinOnce, DetachKeys: keys, } container.StreamConfig.AttachStreams(&cfg) inStream, outStream, errStream, err := c.GetStreams() if err != nil { return err } defer inStream.Close() if !container.Config.Tty && c.MuxStreams { errStream = stdcopy.NewStdWriter(errStream, stdcopy.Stderr) outStream = stdcopy.NewStdWriter(outStream, stdcopy.Stdout) } if cfg.UseStdin { cfg.Stdin = inStream } if cfg.UseStdout { cfg.Stdout = outStream } if cfg.UseStderr { cfg.Stderr = errStream } if err := daemon.containerAttach(container, &cfg, c.Logs, c.Stream); err != nil { fmt.Fprintf(outStream, "Error attaching: %s\n", err) } return nil } // ContainerAttachRaw attaches the provided streams to the container's stdio func (daemon *Daemon) ContainerAttachRaw(prefixOrName string, stdin io.ReadCloser, stdout, stderr io.Writer, doStream bool, attached chan struct{}) error { container, err := daemon.GetContainer(prefixOrName) if err != nil { return err } cfg := stream.AttachConfig{ UseStdin: stdin != nil, UseStdout: stdout != nil, UseStderr: stderr != nil, TTY: container.Config.Tty, CloseStdin: container.Config.StdinOnce, } container.StreamConfig.AttachStreams(&cfg) close(attached) if cfg.UseStdin { cfg.Stdin = stdin } if cfg.UseStdout { cfg.Stdout = stdout } if cfg.UseStderr { cfg.Stderr = stderr } return daemon.containerAttach(container, &cfg, false, doStream) } func (daemon *Daemon) containerAttach(c *container.Container, cfg *stream.AttachConfig, logs, doStream bool) error { if logs { logDriver, logCreated, err := daemon.getLogger(c) if err != nil { return err } if logCreated { defer func() { if err = logDriver.Close(); err != nil { logrus.Errorf("Error closing logger: %v", err) } }() } cLog, ok := logDriver.(logger.LogReader) if !ok { return logger.ErrReadLogsNotSupported{} } logs := cLog.ReadLogs(logger.ReadConfig{Tail: -1}) defer logs.Close() LogLoop: for { select { case msg, ok := <-logs.Msg: if !ok { break LogLoop } if msg.Source == "stdout" && cfg.Stdout != nil { cfg.Stdout.Write(msg.Line) } if msg.Source == "stderr" && cfg.Stderr != nil { cfg.Stderr.Write(msg.Line) } case err := <-logs.Err: logrus.Errorf("Error streaming logs: %v", err) break LogLoop } } } daemon.LogContainerEvent(c, "attach") if !doStream { return nil } if cfg.Stdin != nil { r, w := io.Pipe() go func(stdin io.ReadCloser) { defer w.Close() defer logrus.Debug("Closing buffered stdin pipe") io.Copy(w, stdin) }(cfg.Stdin) cfg.Stdin = r } if !c.Config.OpenStdin { cfg.Stdin = nil } if c.Config.StdinOnce && !c.Config.Tty { // Wait for the container to stop before returning. waitChan := c.Wait(context.Background(), container.WaitConditionNotRunning) defer func() { _ = <-waitChan // Ignore returned exit code. }() } ctx := c.InitAttachContext() err := <-c.StreamConfig.CopyStreams(ctx, cfg) if err != nil { if _, ok := err.(term.EscapeError); ok { daemon.LogContainerEvent(c, "detach") } else { logrus.Errorf("attach failed with error: %v", err) } } return nil }