Merge pull request #124 from crawford/networkd

feat(networkd): Adding support for debian-interface-to-networkd conversion

system/networkd.go

@@ -0,0 +1,89 @@
+package system
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net"
+	"os/exec"
+	"path"
+
+	"github.com/coreos/coreos-cloudinit/network"
+	"github.com/coreos/coreos-cloudinit/third_party/github.com/dotcloud/docker/pkg/netlink"
+)
+
+const (
+	runtimeNetworkPath = "/run/systemd/network"
+)
+
+func RestartNetwork(interfaces []network.InterfaceGenerator) (err error) {
+	defer func() {
+		if e := restartNetworkd(); e != nil {
+			err = e
+		}
+	}()
+
+	if err = downNetworkInterfaces(interfaces); err != nil {
+		return
+	}
+
+	if err = probe8012q(); err != nil {
+		return
+	}
+	return
+}
+
+func downNetworkInterfaces(interfaces []network.InterfaceGenerator) error {
+	sysInterfaceMap := make(map[string]*net.Interface)
+	if systemInterfaces, err := net.Interfaces(); err == nil {
+		for _, iface := range systemInterfaces {
+			sysInterfaceMap[iface.Name] = &iface
+		}
+	} else {
+		return err
+	}
+
+	for _, iface := range interfaces {
+		if systemInterface, ok := sysInterfaceMap[iface.Name()]; ok {
+			if err := netlink.NetworkLinkDown(systemInterface); err != nil {
+				fmt.Printf("Error while downing interface %q (%s). Continuing...\n", systemInterface.Name, err)
+			}
+		}
+	}
+
+	return nil
+}
+
+func probe8012q() error {
+	return exec.Command("modprobe", "8021q").Run()
+}
+
+func restartNetworkd() error {
+	_, err := RunUnitCommand("restart", "systemd-networkd.service")
+	return err
+}
+
+func WriteNetworkdConfigs(interfaces []network.InterfaceGenerator) error {
+	for _, iface := range interfaces {
+		filename := path.Join(runtimeNetworkPath, fmt.Sprintf("%s.netdev", iface.Name()))
+		if err := writeConfig(filename, iface.Netdev()); err != nil {
+			return err
+		}
+		filename = path.Join(runtimeNetworkPath, fmt.Sprintf("%s.link", iface.Name()))
+		if err := writeConfig(filename, iface.Link()); err != nil {
+			return err
+		}
+		filename = path.Join(runtimeNetworkPath, fmt.Sprintf("%s.network", iface.Name()))
+		if err := writeConfig(filename, iface.Network()); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func writeConfig(filename string, config string) error {
+	if config == "" {
+		return nil
+	}
+
+	return ioutil.WriteFile(filename, []byte(config), 0444)
+}