Browse code
Remote communication between engines using beam
Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Solomon Hykes authored on 2014/04/24 16:46:32Showing 2 changed files
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+package engine |
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+ |
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+import ( |
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+ "fmt" |
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+ "github.com/dotcloud/docker/pkg/beam" |
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+ "github.com/dotcloud/docker/pkg/beam/data" |
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+ "io" |
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+ "os" |
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+ "strconv" |
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+ "sync" |
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+) |
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+ |
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+type Sender struct {
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+ beam.Sender |
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+} |
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+ |
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+func NewSender(s beam.Sender) *Sender {
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+ return &Sender{s}
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+} |
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+ |
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+func (s *Sender) Install(eng *Engine) error {
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+ // FIXME: this doesn't exist yet. |
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+ eng.RegisterCatchall(s.Handle) |
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+ return nil |
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+} |
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+ |
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+func (s *Sender) Handle(job *Job) Status {
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+ msg := data.Empty().Set("cmd", append([]string{job.Name}, job.Args...)...)
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+ peer, err := beam.SendConn(s, msg.Bytes()) |
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+ if err != nil {
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+ return job.Errorf("beamsend: %v", err)
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+ } |
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+ defer peer.Close() |
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+ var tasks sync.WaitGroup |
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+ defer tasks.Wait() |
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+ r := beam.NewRouter(nil) |
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+ r.NewRoute().KeyStartsWith("cmd", "log", "stdout").HasAttachment().Handler(func(p []byte, stdout *os.File) error {
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+ tasks.Add(1) |
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+ io.Copy(job.Stdout, stdout) |
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+ tasks.Done() |
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+ return nil |
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+ }) |
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+ r.NewRoute().KeyStartsWith("cmd", "log", "stderr").HasAttachment().Handler(func(p []byte, stderr *os.File) error {
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+ tasks.Add(1) |
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+ io.Copy(job.Stderr, stderr) |
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+ tasks.Done() |
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+ return nil |
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+ }) |
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+ var status int |
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+ r.NewRoute().KeyStartsWith("cmd", "status").Handler(func(p []byte, f *os.File) error {
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+ cmd := data.Message(p).Get("cmd")
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+ if len(cmd) != 3 {
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+ return fmt.Errorf("usage: %s <0-127>", cmd[0])
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+ } |
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+ s, err := strconv.ParseUint(cmd[2], 10, 8) |
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+ if err != nil {
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+ return fmt.Errorf("usage: %s <0-127>", cmd[0])
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+ } |
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+ status = int(s) |
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+ return nil |
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+ |
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+ }) |
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+ if _, err := beam.Copy(r, peer); err != nil {
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+ return job.Errorf("%v", err)
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+ } |
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+ return Status(status) |
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+} |
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+ |
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+type Receiver struct {
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+ *Engine |
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+ peer beam.Receiver |
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+} |
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+ |
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+func NewReceiver(peer beam.Receiver) *Receiver {
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+ return &Receiver{Engine: New(), peer: peer}
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+} |
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+ |
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+func (rcv *Receiver) Run() error {
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+ r := beam.NewRouter(nil) |
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+ r.NewRoute().KeyExists("cmd").Handler(func(p []byte, f *os.File) error {
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+ // Use the attachment as a beam return channel |
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+ peer, err := beam.FileConn(f) |
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+ if err != nil {
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+ f.Close() |
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+ return err |
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+ } |
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+ cmd := data.Message(p).Get("cmd")
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+ job := rcv.Engine.Job(cmd[0], cmd[1:]...) |
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+ stdout, err := beam.SendPipe(peer, data.Empty().Set("cmd", "log", "stdout").Bytes())
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+ if err != nil {
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+ return err |
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+ } |
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+ job.Stdout.Add(stdout) |
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+ stderr, err := beam.SendPipe(peer, data.Empty().Set("cmd", "log", "stderr").Bytes())
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+ if err != nil {
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+ return err |
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+ } |
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+ job.Stderr.Add(stderr) |
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+ // ignore error because we pass the raw status |
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+ job.Run() |
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+ err = peer.Send(data.Empty().Set("cmd", "status", fmt.Sprintf("%d", job.status)).Bytes(), nil)
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+ if err != nil {
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+ return err |
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+ } |
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+ return nil |
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+ }) |
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+ _, err := beam.Copy(r, rcv.peer) |
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+ return err |
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+} |