// Setup networking
func setupNetworking(args *execdriver.InitArgs) error {
if args.Ip != "" {
// eth0
iface, err := net.InterfaceByName("eth0")
if err != nil {
return fmt.Errorf("Unable to set up networking: %v", err)
}
ip, ipNet, err := net.ParseCIDR(args.Ip)
if err != nil {
return fmt.Errorf("Unable to set up networking: %v", err)
}
if err := netlink.NetworkLinkAddIp(iface, ip, ipNet); err != nil {
return fmt.Errorf("Unable to set up networking: %v", err)
}
if err := netlink.NetworkSetMTU(iface, args.Mtu); err != nil {
return fmt.Errorf("Unable to set MTU: %v", err)
}
if err := netlink.NetworkLinkUp(iface); err != nil {
return fmt.Errorf("Unable to set up networking: %v", err)
}
// loopback
iface, err = net.InterfaceByName("lo")
if err != nil {
return fmt.Errorf("Unable to set up networking: %v", err)
}
if err := netlink.NetworkLinkUp(iface); err != nil {
return fmt.Errorf("Unable to set up networking: %v", err)
}
}
if args.Gateway != "" {
gw := net.ParseIP(args.Gateway)
if gw == nil {
return fmt.Errorf("Unable to set up networking, %s is not a valid gateway IP", args.Gateway)
}
if err := netlink.AddDefaultGw(gw); err != nil {
return fmt.Errorf("Unable to set up networking: %v", err)
}
}
return nil
}
// CreateBridgeIface creates a network bridge interface on the host system with the name `ifaceName`,
// and attempts to configure it with an address which doesn't conflict with any other interface on the host.
// If it can't find an address which doesn't conflict, it will return an error.
func createBridge(bridgeIP string) error {
nameservers := []string{}
resolvConf, _ := utils.GetResolvConf()
// we don't check for an error here, because we don't really care
// if we can't read /etc/resolv.conf. So instead we skip the append
// if resolvConf is nil. It either doesn't exist, or we can't read it
// for some reason.
if resolvConf != nil {
nameservers = append(nameservers, utils.GetNameserversAsCIDR(resolvConf)...)
}
var ifaceAddr string
if len(bridgeIP) != 0 {
_, _, err := net.ParseCIDR(bridgeIP)
if err != nil {
return err
}
ifaceAddr = bridgeIP
} else {
for _, addr := range addrs {
_, dockerNetwork, err := net.ParseCIDR(addr)
if err != nil {
return err
}
if err := networkdriver.CheckNameserverOverlaps(nameservers, dockerNetwork); err == nil {
if err := networkdriver.CheckRouteOverlaps(dockerNetwork); err == nil {
ifaceAddr = addr
break
} else {
utils.Debugf("%s %s", addr, err)
}
}
}
}
if ifaceAddr == "" {
return fmt.Errorf("Could not find a free IP address range for interface '%s'. Please configure its address manually and run 'docker -b %s'", bridgeIface, bridgeIface)
}
utils.Debugf("Creating bridge %s with network %s", bridgeIface, ifaceAddr)
if err := createBridgeIface(bridgeIface); err != nil {
return err
}
iface, err := net.InterfaceByName(bridgeIface)
if err != nil {
return err
}
ipAddr, ipNet, err := net.ParseCIDR(ifaceAddr)
if err != nil {
return err
}
if netlink.NetworkLinkAddIp(iface, ipAddr, ipNet); err != nil {
return fmt.Errorf("Unable to add private network: %s", err)
}
if err := netlink.NetworkLinkUp(iface); err != nil {
return fmt.Errorf("Unable to start network bridge: %s", err)
}
return nil
}