func (c *Cmd) Start() error {
if c.started {
return errors.New("exec: already started")
}
c.started = true
if c.cluster == nil {
var err error
c.cluster, err = cluster.NewClient()
if err != nil {
return err
}
c.closeCluster = true
}
hosts, err := c.cluster.ListHosts()
if err != nil {
return err
}
if c.HostID == "" {
// TODO: check if this is actually random
for c.HostID = range hosts {
break
}
}
if c.JobID == "" {
c.JobID = cluster.RandomJobID("")
}
job := &host.Job{
ID: c.JobID,
Config: &docker.Config{
Image: c.Image,
Cmd: c.Cmd,
Tty: c.TTY,
Env: formatEnv(c.Env),
},
Attributes: c.Attrs,
}
if c.Stdout != nil || c.stdoutPipe != nil {
job.Config.AttachStdout = true
}
if c.Stderr != nil || c.stderrPipe != nil {
job.Config.AttachStderr = true
}
if c.Stdin != nil || c.stdinPipe != nil {
job.Config.AttachStdin = true
job.Config.OpenStdin = true
job.Config.StdinOnce = true
}
c.host, err = c.cluster.DialHost(c.HostID)
if err != nil {
return err
}
// subscribe to host events
ch := make(chan *host.Event)
stream := c.host.StreamEvents(job.ID, ch)
go func() {
for event := range ch {
if event.Event == "stop" || event.Event == "error" {
close(c.done)
return
}
}
c.streamErr = stream.Err()
close(c.done)
// TODO: handle disconnections
}()
var rwc cluster.ReadWriteCloser
var attachWait func() error
if c.Stdout != nil || c.Stderr != nil || c.Stdin != nil ||
c.stdoutPipe != nil || c.stderrPipe != nil || c.stdinPipe != nil {
req := &host.AttachReq{
JobID: job.ID,
Height: c.TermHeight,
Width: c.TermWidth,
Flags: host.AttachFlagStream,
}
if job.Config.AttachStdout {
req.Flags |= host.AttachFlagStdout
}
if job.Config.AttachStderr {
req.Flags |= host.AttachFlagStderr
}
if job.Config.AttachStdin {
req.Flags |= host.AttachFlagStdin
}
rwc, attachWait, err = c.host.Attach(req, true)
if err != nil {
c.close()
return err
}
}
goroutines := make([]func() error, 0, 4)
c.attachConn = rwc
if attachWait != nil {
goroutines = append(goroutines, attachWait)
}
if c.stdinPipe != nil {
c.stdinPipe.set(writeCloseCloser{rwc})
} else if c.Stdin != nil {
goroutines = append(goroutines, func() error {
_, err := io.Copy(rwc, c.Stdin)
rwc.CloseWrite()
return err
})
}
if !c.TTY {
if c.stdoutPipe != nil || c.stderrPipe != nil {
stdout, stderr := demultiplex.Streams(rwc)
if c.stdoutPipe != nil {
c.stdoutPipe.set(stdout)
} else if c.Stdout != nil {
goroutines = append(goroutines, cpFunc(c.Stdout, stdout))
}
if c.stderrPipe != nil {
c.stderrPipe.set(stderr)
} else if c.Stderr != nil {
goroutines = append(goroutines, cpFunc(c.Stderr, stderr))
}
} else if c.Stdout != nil || c.Stderr != nil {
goroutines = append(goroutines, func() error {
return demultiplex.Copy(c.Stdout, c.Stderr, rwc)
})
}
} else if c.stdoutPipe != nil {
c.stdoutPipe.set(rwc)
} else if c.Stdout != nil {
goroutines = append(goroutines, cpFunc(c.Stdout, rwc))
}
c.errCh = make(chan error, len(goroutines))
for _, fn := range goroutines {
go func(fn func() error) {
c.errCh <- fn()
}(fn)
}
_, err = c.cluster.AddJobs(&host.AddJobsReq{HostJobs: map[string][]*host.Job{c.HostID: {job}}})
return err
}
