github.com/squaremo/docker@v1.3.2-0.20150516120342-42cfc9554972/api/client/start.go (about)

     1  package client
     2  
     3  import (
     4  	"encoding/json"
     5  	"fmt"
     6  	"io"
     7  	"net/url"
     8  	"os"
     9  
    10  	"github.com/Sirupsen/logrus"
    11  	"github.com/docker/docker/api/types"
    12  	flag "github.com/docker/docker/pkg/mflag"
    13  	"github.com/docker/docker/pkg/promise"
    14  	"github.com/docker/docker/pkg/signal"
    15  )
    16  
    17  func (cli *DockerCli) forwardAllSignals(cid string) chan os.Signal {
    18  	sigc := make(chan os.Signal, 128)
    19  	signal.CatchAll(sigc)
    20  	go func() {
    21  		for s := range sigc {
    22  			if s == signal.SIGCHLD {
    23  				continue
    24  			}
    25  			var sig string
    26  			for sigStr, sigN := range signal.SignalMap {
    27  				if sigN == s {
    28  					sig = sigStr
    29  					break
    30  				}
    31  			}
    32  			if sig == "" {
    33  				fmt.Fprintf(cli.err, "Unsupported signal: %v. Discarding.\n", s)
    34  			}
    35  			if _, _, err := readBody(cli.call("POST", fmt.Sprintf("/containers/%s/kill?signal=%s", cid, sig), nil, nil)); err != nil {
    36  				logrus.Debugf("Error sending signal: %s", err)
    37  			}
    38  		}
    39  	}()
    40  	return sigc
    41  }
    42  
    43  // CmdStart starts one or more stopped containers.
    44  //
    45  // Usage: docker start [OPTIONS] CONTAINER [CONTAINER...]
    46  func (cli *DockerCli) CmdStart(args ...string) error {
    47  	var (
    48  		cErr chan error
    49  		tty  bool
    50  
    51  		cmd       = cli.Subcmd("start", "CONTAINER [CONTAINER...]", "Start one or more stopped containers", true)
    52  		attach    = cmd.Bool([]string{"a", "-attach"}, false, "Attach STDOUT/STDERR and forward signals")
    53  		openStdin = cmd.Bool([]string{"i", "-interactive"}, false, "Attach container's STDIN")
    54  	)
    55  
    56  	cmd.Require(flag.Min, 1)
    57  	cmd.ParseFlags(args, true)
    58  
    59  	if *attach || *openStdin {
    60  		if cmd.NArg() > 1 {
    61  			return fmt.Errorf("You cannot start and attach multiple containers at once.")
    62  		}
    63  
    64  		stream, _, err := cli.call("GET", "/containers/"+cmd.Arg(0)+"/json", nil, nil)
    65  		if err != nil {
    66  			return err
    67  		}
    68  
    69  		var c types.ContainerJSON
    70  		if err := json.NewDecoder(stream).Decode(&c); err != nil {
    71  			return err
    72  		}
    73  
    74  		tty = c.Config.Tty
    75  
    76  		if !tty {
    77  			sigc := cli.forwardAllSignals(cmd.Arg(0))
    78  			defer signal.StopCatch(sigc)
    79  		}
    80  
    81  		var in io.ReadCloser
    82  
    83  		v := url.Values{}
    84  		v.Set("stream", "1")
    85  
    86  		if *openStdin && c.Config.OpenStdin {
    87  			v.Set("stdin", "1")
    88  			in = cli.in
    89  		}
    90  
    91  		v.Set("stdout", "1")
    92  		v.Set("stderr", "1")
    93  
    94  		hijacked := make(chan io.Closer)
    95  		// Block the return until the chan gets closed
    96  		defer func() {
    97  			logrus.Debugf("CmdStart() returned, defer waiting for hijack to finish.")
    98  			if _, ok := <-hijacked; ok {
    99  				fmt.Fprintln(cli.err, "Hijack did not finish (chan still open)")
   100  			}
   101  			cli.in.Close()
   102  		}()
   103  		cErr = promise.Go(func() error {
   104  			return cli.hijack("POST", "/containers/"+cmd.Arg(0)+"/attach?"+v.Encode(), tty, in, cli.out, cli.err, hijacked, nil)
   105  		})
   106  
   107  		// Acknowledge the hijack before starting
   108  		select {
   109  		case closer := <-hijacked:
   110  			// Make sure that the hijack gets closed when returning (results
   111  			// in closing the hijack chan and freeing server's goroutines)
   112  			if closer != nil {
   113  				defer closer.Close()
   114  			}
   115  		case err := <-cErr:
   116  			if err != nil {
   117  				return err
   118  			}
   119  		}
   120  	}
   121  
   122  	var encounteredError error
   123  	var errNames []string
   124  	for _, name := range cmd.Args() {
   125  		_, _, err := readBody(cli.call("POST", "/containers/"+name+"/start", nil, nil))
   126  		if err != nil {
   127  			if !*attach && !*openStdin {
   128  				// attach and openStdin is false means it could be starting multiple containers
   129  				// when a container start failed, show the error message and start next
   130  				fmt.Fprintf(cli.err, "%s\n", err)
   131  				errNames = append(errNames, name)
   132  			} else {
   133  				encounteredError = err
   134  			}
   135  		} else {
   136  			if !*attach && !*openStdin {
   137  				fmt.Fprintf(cli.out, "%s\n", name)
   138  			}
   139  		}
   140  	}
   141  
   142  	if len(errNames) > 0 {
   143  		encounteredError = fmt.Errorf("Error: failed to start containers: %v", errNames)
   144  	}
   145  	if encounteredError != nil {
   146  		return encounteredError
   147  	}
   148  
   149  	if *openStdin || *attach {
   150  		if tty && cli.isTerminalOut {
   151  			if err := cli.monitorTtySize(cmd.Arg(0), false); err != nil {
   152  				fmt.Fprintf(cli.err, "Error monitoring TTY size: %s\n", err)
   153  			}
   154  		}
   155  		if attchErr := <-cErr; attchErr != nil {
   156  			return attchErr
   157  		}
   158  		_, status, err := getExitCode(cli, cmd.Arg(0))
   159  		if err != nil {
   160  			return err
   161  		}
   162  		if status != 0 {
   163  			return StatusError{StatusCode: status}
   164  		}
   165  	}
   166  	return nil
   167  }