Ejemplo n.º 1
0
// Allocate an external port and map it to the interface
func AllocatePort(job *engine.Job) engine.Status {
	var (
		err error

		ip            = defaultBindingIP
		id            = job.Args[0]
		hostIP        = job.Getenv("HostIP")
		hostPort      = job.GetenvInt("HostPort")
		containerPort = job.GetenvInt("ContainerPort")
		proto         = job.Getenv("Proto")
		network       = currentInterfaces.Get(id)
	)

	if hostIP != "" {
		ip = net.ParseIP(hostIP)
		if ip == nil {
			return job.Errorf("Bad parameter: invalid host ip %s", hostIP)
		}
	}

	// host ip, proto, and host port
	var container net.Addr
	switch proto {
	case "tcp":
		container = &net.TCPAddr{IP: network.IP, Port: containerPort}
	case "udp":
		container = &net.UDPAddr{IP: network.IP, Port: containerPort}
	default:
		return job.Errorf("unsupported address type %s", proto)
	}

	//
	// Try up to 10 times to get a port that's not already allocated.
	//
	// In the event of failure to bind, return the error that portmapper.Map
	// yields.
	//

	var host net.Addr
	for i := 0; i < MaxAllocatedPortAttempts; i++ {
		if host, err = portmapper.Map(container, ip, hostPort); err == nil {
			break
		}
		// There is no point in immediately retrying to map an explicitly
		// chosen port.
		if hostPort != 0 {
			job.Logf("Failed to allocate and map port %d: %s", hostPort, err)
			break
		}
		job.Logf("Failed to allocate and map port: %s, retry: %d", err, i+1)
	}

	if err != nil {
		return job.Error(err)
	}

	network.PortMappings = append(network.PortMappings, host)

	out := engine.Env{}
	switch netAddr := host.(type) {
	case *net.TCPAddr:
		out.Set("HostIP", netAddr.IP.String())
		out.SetInt("HostPort", netAddr.Port)
	case *net.UDPAddr:
		out.Set("HostIP", netAddr.IP.String())
		out.SetInt("HostPort", netAddr.Port)
	}
	if _, err := out.WriteTo(job.Stdout); err != nil {
		return job.Error(err)
	}

	return engine.StatusOK
}