github.com/flavio/docker@v0.1.3-0.20170117145210-f63d1a6eec47/cli/command/container/attach.go (about)

     1  package container
     2  
     3  import (
     4  	"errors"
     5  	"io"
     6  	"net/http/httputil"
     7  
     8  	"github.com/Sirupsen/logrus"
     9  	"github.com/docker/docker/api/types"
    10  	"github.com/docker/docker/cli"
    11  	"github.com/docker/docker/cli/command"
    12  	"github.com/docker/docker/pkg/signal"
    13  	"github.com/spf13/cobra"
    14  	"golang.org/x/net/context"
    15  )
    16  
    17  type attachOptions struct {
    18  	noStdin    bool
    19  	proxy      bool
    20  	detachKeys string
    21  
    22  	container string
    23  }
    24  
    25  // NewAttachCommand creates a new cobra.Command for `docker attach`
    26  func NewAttachCommand(dockerCli *command.DockerCli) *cobra.Command {
    27  	var opts attachOptions
    28  
    29  	cmd := &cobra.Command{
    30  		Use:   "attach [OPTIONS] CONTAINER",
    31  		Short: "Attach to a running container",
    32  		Args:  cli.ExactArgs(1),
    33  		RunE: func(cmd *cobra.Command, args []string) error {
    34  			opts.container = args[0]
    35  			return runAttach(dockerCli, &opts)
    36  		},
    37  	}
    38  
    39  	flags := cmd.Flags()
    40  	flags.BoolVar(&opts.noStdin, "no-stdin", false, "Do not attach STDIN")
    41  	flags.BoolVar(&opts.proxy, "sig-proxy", true, "Proxy all received signals to the process")
    42  	flags.StringVar(&opts.detachKeys, "detach-keys", "", "Override the key sequence for detaching a container")
    43  	return cmd
    44  }
    45  
    46  func runAttach(dockerCli *command.DockerCli, opts *attachOptions) error {
    47  	ctx := context.Background()
    48  	client := dockerCli.Client()
    49  
    50  	c, err := client.ContainerInspect(ctx, opts.container)
    51  	if err != nil {
    52  		return err
    53  	}
    54  
    55  	if !c.State.Running {
    56  		return errors.New("You cannot attach to a stopped container, start it first")
    57  	}
    58  
    59  	if c.State.Paused {
    60  		return errors.New("You cannot attach to a paused container, unpause it first")
    61  	}
    62  
    63  	if err := dockerCli.In().CheckTty(!opts.noStdin, c.Config.Tty); err != nil {
    64  		return err
    65  	}
    66  
    67  	if opts.detachKeys != "" {
    68  		dockerCli.ConfigFile().DetachKeys = opts.detachKeys
    69  	}
    70  
    71  	options := types.ContainerAttachOptions{
    72  		Stream:     true,
    73  		Stdin:      !opts.noStdin && c.Config.OpenStdin,
    74  		Stdout:     true,
    75  		Stderr:     true,
    76  		DetachKeys: dockerCli.ConfigFile().DetachKeys,
    77  	}
    78  
    79  	var in io.ReadCloser
    80  	if options.Stdin {
    81  		in = dockerCli.In()
    82  	}
    83  
    84  	if opts.proxy && !c.Config.Tty {
    85  		sigc := ForwardAllSignals(ctx, dockerCli, opts.container)
    86  		defer signal.StopCatch(sigc)
    87  	}
    88  
    89  	resp, errAttach := client.ContainerAttach(ctx, opts.container, options)
    90  	if errAttach != nil && errAttach != httputil.ErrPersistEOF {
    91  		// ContainerAttach returns an ErrPersistEOF (connection closed)
    92  		// means server met an error and put it in Hijacked connection
    93  		// keep the error and read detailed error message from hijacked connection later
    94  		return errAttach
    95  	}
    96  	defer resp.Close()
    97  
    98  	if c.Config.Tty && dockerCli.Out().IsTerminal() {
    99  		height, width := dockerCli.Out().GetTtySize()
   100  		// To handle the case where a user repeatedly attaches/detaches without resizing their
   101  		// terminal, the only way to get the shell prompt to display for attaches 2+ is to artificially
   102  		// resize it, then go back to normal. Without this, every attach after the first will
   103  		// require the user to manually resize or hit enter.
   104  		resizeTtyTo(ctx, client, opts.container, height+1, width+1, false)
   105  
   106  		// After the above resizing occurs, the call to MonitorTtySize below will handle resetting back
   107  		// to the actual size.
   108  		if err := MonitorTtySize(ctx, dockerCli, opts.container, false); err != nil {
   109  			logrus.Debugf("Error monitoring TTY size: %s", err)
   110  		}
   111  	}
   112  	if err := holdHijackedConnection(ctx, dockerCli, c.Config.Tty, in, dockerCli.Out(), dockerCli.Err(), resp); err != nil {
   113  		return err
   114  	}
   115  
   116  	if errAttach != nil {
   117  		return errAttach
   118  	}
   119  
   120  	_, status, err := getExitCode(ctx, dockerCli, opts.container)
   121  	if err != nil {
   122  		return err
   123  	}
   124  	if status != 0 {
   125  		return cli.StatusError{StatusCode: status}
   126  	}
   127  
   128  	return nil
   129  }