func InitDriver(job *engine.Job) engine.Status {
var (
network *net.IPNet
enableIPTables = job.GetenvBool("EnableIptables")
icc = job.GetenvBool("InterContainerCommunication")
ipForward = job.GetenvBool("EnableIpForward")
bridgeIP = job.Getenv("BridgeIP")
)
if defaultIP := job.Getenv("DefaultBindingIP"); defaultIP != "" {
defaultBindingIP = net.ParseIP(defaultIP)
}
bridgeIface = job.Getenv("BridgeIface")
usingDefaultBridge := false
if bridgeIface == "" {
usingDefaultBridge = true
bridgeIface = DefaultNetworkBridge
}
addr, err := networkdriver.GetIfaceAddr(bridgeIface)
if err != nil {
// If we're not using the default bridge, fail without trying to create it
if !usingDefaultBridge {
job.Logf("bridge not found: %s", bridgeIface)
return job.Error(err)
}
// If the iface is not found, try to create it
job.Logf("creating new bridge for %s", bridgeIface)
if err := createBridge(bridgeIP); err != nil {
return job.Error(err)
}
job.Logf("getting iface addr")
addr, err = networkdriver.GetIfaceAddr(bridgeIface)
if err != nil {
return job.Error(err)
}
network = addr.(*net.IPNet)
} else {
network = addr.(*net.IPNet)
// validate that the bridge ip matches the ip specified by BridgeIP
if bridgeIP != "" {
bip, _, err := net.ParseCIDR(bridgeIP)
if err != nil {
return job.Error(err)
}
if !network.IP.Equal(bip) {
return job.Errorf("bridge ip (%s) does not match existing bridge configuration %s", network.IP, bip)
}
}
}
// Configure iptables for link support
if enableIPTables {
if err := setupIPTables(addr, icc); err != nil {
return job.Error(err)
}
}
if ipForward {
// Enable IPv4 forwarding
if err := ioutil.WriteFile("/proc/sys/net/ipv4/ip_forward", []byte{'1', '\n'}, 0644); err != nil {
job.Logf("WARNING: unable to enable IPv4 forwarding: %s\n", err)
}
}
// We can always try removing the iptables
if err := iptables.RemoveExistingChain("DOCKER"); err != nil {
return job.Error(err)
}
if enableIPTables {
chain, err := iptables.NewChain("DOCKER", bridgeIface)
if err != nil {
return job.Error(err)
}
portmapper.SetIptablesChain(chain)
}
bridgeNetwork = network
// https://github.com/dockercn/docker/issues/2768
job.Eng.Hack_SetGlobalVar("httpapi.bridgeIP", bridgeNetwork.IP)
for name, f := range map[string]engine.Handler{
"allocate_interface": Allocate,
"release_interface": Release,
"allocate_port": AllocatePort,
"link": LinkContainers,
} {
if err := job.Eng.Register(name, f); err != nil {
return job.Error(err)
}
}
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
}