// Allocate a network interface
func Allocate(job *engine.Job) engine.Status {
var (
ip *net.IP
err error
id = job.Args[0]
requestedIP = net.ParseIP(job.Getenv("RequestedIP"))
)
if requestedIP != nil {
ip, err = ipallocator.RequestIP(bridgeNetwork, &requestedIP)
} else {
ip, err = ipallocator.RequestIP(bridgeNetwork, nil)
}
if err != nil {
return job.Error(err)
}
out := engine.Env{}
out.Set("IP", ip.String())
out.Set("Mask", bridgeNetwork.Mask.String())
out.Set("Gateway", bridgeNetwork.IP.String())
out.Set("Bridge", bridgeIface)
size, _ := bridgeNetwork.Mask.Size()
out.SetInt("IPPrefixLen", size)
currentInterfaces.Set(id, &networkInterface{
IP: *ip,
})
out.WriteTo(job.Stdout)
return engine.StatusOK
}
// 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)
}
// 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
}
if allocerr, ok := err.(portallocator.ErrPortAlreadyAllocated); ok {
// There is no point in immediately retrying to map an explicitly
// chosen port.
if hostPort != 0 {
job.Logf("Failed to bind %s for container address %s: %s", allocerr.IPPort(), container.String(), allocerr.Error())
break
}
// Automatically chosen 'free' port failed to bind: move on the next.
job.Logf("Failed to bind %s for container address %s. Trying another port.", allocerr.IPPort(), container.String())
} else {
// some other error during mapping
job.Logf("Received an unexpected error during port allocation: %s", err.Error())
break
}
}
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
}