Example #1
0
func (s *Sender) Handle(job *Job) Status {
	cmd := append([]string{job.Name}, job.Args...)
	env := data.Encode(job.Env().MultiMap())
	msg := data.Empty().Set("cmd", cmd...).Set("env", env)
	peer, err := beam.SendConn(s, msg.Bytes())
	if err != nil {
		return job.Errorf("beamsend: %v", err)
	}
	defer peer.Close()
	var tasks sync.WaitGroup
	defer tasks.Wait()
	r := beam.NewRouter(nil)
	r.NewRoute().KeyStartsWith("cmd", "log", "stdout").HasAttachment().Handler(func(p []byte, stdout *os.File) error {
		tasks.Add(1)
		go func() {
			io.Copy(job.Stdout, stdout)
			stdout.Close()
			tasks.Done()
		}()
		return nil
	})
	r.NewRoute().KeyStartsWith("cmd", "log", "stderr").HasAttachment().Handler(func(p []byte, stderr *os.File) error {
		tasks.Add(1)
		go func() {
			io.Copy(job.Stderr, stderr)
			stderr.Close()
			tasks.Done()
		}()
		return nil
	})
	r.NewRoute().KeyStartsWith("cmd", "log", "stdin").HasAttachment().Handler(func(p []byte, stdin *os.File) error {
		go func() {
			io.Copy(stdin, job.Stdin)
			stdin.Close()
		}()
		return nil
	})
	var status int
	r.NewRoute().KeyStartsWith("cmd", "status").Handler(func(p []byte, f *os.File) error {
		cmd := data.Message(p).Get("cmd")
		if len(cmd) != 2 {
			return fmt.Errorf("usage: %s <0-127>", cmd[0])
		}
		s, err := strconv.ParseUint(cmd[1], 10, 8)
		if err != nil {
			return fmt.Errorf("usage: %s <0-127>", cmd[0])
		}
		status = int(s)
		return nil

	})
	if _, err := beam.Copy(r, peer); err != nil {
		return job.Errorf("%v", err)
	}
	return Status(status)
}
Example #2
0
//	1) Find a handler for the command (if no handler, fail)
//	2) Attach new in & out pair to the handler
//	3) [in the background] Copy handler output to our own output
//	4) [in the background] Run the handler
//	5) Recursively executeScript() all children commands and wait for them to complete
//	6) Wait for handler to return and (shortly afterwards) output copy to complete
//	7) Profit
func executeCommand(out beam.Sender, cmd *dockerscript.Command) error {
	if flX {
		fmt.Printf("+ %v\n", strings.Replace(strings.TrimRight(cmd.String(), "\n"), "\n", "\n+ ", -1))
	}
	Debugf("executeCommand(%s)\n", strings.Join(cmd.Args, " "))
	defer Debugf("executeCommand(%s) DONE\n", strings.Join(cmd.Args, " "))
	if len(cmd.Args) == 0 {
		return fmt.Errorf("empty command")
	}
	Debugf("[executeCommand] sending job '%s'\n", strings.Join(cmd.Args, " "))
	job, err := beam.SendConn(out, data.Empty().Set("cmd", cmd.Args...).Set("type", "job").Bytes())
	if err != nil {
		return fmt.Errorf("%v\n", err)
	}
	var tasks sync.WaitGroup
	tasks.Add(1)
	Debugf("[executeCommand] spawning background copy of the output of '%s'\n", strings.Join(cmd.Args, " "))
	go func() {
		if out != nil {
			Debugf("[executeCommand] background copy of the output of '%s'\n", strings.Join(cmd.Args, " "))
			n, err := beam.Copy(out, job)
			if err != nil {
				Fatalf("[executeCommand] [%s] error during background copy: %v\n", strings.Join(cmd.Args, " "), err)
			}
			Debugf("[executeCommand] background copy done of the output of '%s': copied %d messages\n", strings.Join(cmd.Args, " "), n)
		}
		tasks.Done()
	}()
	// depth-first execution of children commands
	// executeScript() blocks until all commands are completed
	Debugf("[executeCommand] recursively running children of '%s'\n", strings.Join(cmd.Args, " "))
	executeScript(job, cmd.Children)
	Debugf("[executeCommand] DONE recursively running children of '%s'\n", strings.Join(cmd.Args, " "))
	job.CloseWrite()
	Debugf("[executeCommand] closing the input of '%s' (all children are completed)\n", strings.Join(cmd.Args, " "))
	Debugf("[executeCommand] waiting for background copy of '%s' to complete...\n", strings.Join(cmd.Args, " "))
	tasks.Wait()
	Debugf("[executeCommand] background copy of '%s' complete! This means the job completed.\n", strings.Join(cmd.Args, " "))
	return nil
}