Split the network unit logic from Apply()

coreos-cloudinit.go

@@ -161,7 +161,7 @@ func main() {
 		os.Exit(2)
 	}
 
-	if flags.printVersion == true {
+	if flags.printVersion {
 		fmt.Printf("coreos-cloudinit %s\n", version)
 		os.Exit(0)
 	}
@@ -188,6 +188,22 @@ func main() {
 		os.Exit(1)
 	}
 
+	log.Printf("Fetching meta-data from datasource of type %q\n", ds.Type())
+	metadata, err := ds.FetchMetadata()
+	if err != nil {
+		log.Printf("Failed fetching meta-data from datasource: %v\n", err)
+		os.Exit(1)
+	}
+	env := initialize.NewEnvironment("/", ds.ConfigRoot(), flags.workspace, flags.sshKeyName, metadata)
+
+	// Setup networking units
+	if flags.convertNetconf != "" {
+		if err := setupNetworkUnits(metadata.NetworkConfig, env, flags.convertNetconf); err != nil {
+			log.Printf("Failed to setup network units: %v\n", err)
+			os.Exit(1)
+		}
+	}
+
 	log.Printf("Fetching user-data from datasource of type %q\n", ds.Type())
 	userdataBytes, err := ds.FetchUserdata()
 	if err != nil {
@@ -216,15 +232,7 @@ func main() {
 		}
 	}
 
-	log.Printf("Fetching meta-data from datasource of type %q\n", ds.Type())
-	metadata, err := ds.FetchMetadata()
-	if err != nil {
-		log.Printf("Failed fetching meta-data from datasource: %v\n", err)
-		os.Exit(1)
-	}
-
 	// Apply environment to user-data
-	env := initialize.NewEnvironment("/", ds.ConfigRoot(), flags.workspace, flags.sshKeyName, metadata)
 	userdata := env.Apply(string(userdataBytes))
 
 	var ccu *config.CloudConfig
@@ -248,26 +256,7 @@ func main() {
 	log.Println("Merging cloud-config from meta-data and user-data")
 	cc := mergeConfigs(ccu, metadata)
 
-	var ifaces []network.InterfaceGenerator
-	if flags.convertNetconf != "" {
-		var err error
-		switch flags.convertNetconf {
-		case "debian":
-			ifaces, err = network.ProcessDebianNetconf(metadata.NetworkConfig.([]byte))
-		case "packet":
-			ifaces, err = network.ProcessPacketNetconf(metadata.NetworkConfig.(packet.NetworkData))
-		case "vmware":
-			ifaces, err = network.ProcessVMwareNetconf(metadata.NetworkConfig.(map[string]string))
-		default:
-			err = fmt.Errorf("Unsupported network config format %q", flags.convertNetconf)
-		}
-		if err != nil {
-			log.Printf("Failed to generate interfaces: %v\n", err)
-			os.Exit(1)
-		}
-	}
-
-	if err = initialize.Apply(cc, ifaces, env); err != nil {
+	if err = initialize.Apply(cc, env); err != nil {
 		log.Printf("Failed to apply cloud-config: %v\n", err)
 		os.Exit(1)
 	}
@@ -284,6 +273,29 @@ func main() {
 	}
 }
 
+func setupNetworkUnits(netConfig interface{}, env *initialize.Environment, netconf string) error {
+	var ifaces []network.InterfaceGenerator
+	var err error
+	switch netconf {
+	case "debian":
+		ifaces, err = network.ProcessDebianNetconf(netConfig.([]byte))
+	case "packet":
+		ifaces, err = network.ProcessPacketNetconf(netConfig.(packet.NetworkData))
+	case "vmware":
+		ifaces, err = network.ProcessVMwareNetconf(netConfig.(map[string]string))
+	default:
+		err = fmt.Errorf("Unsupported network config format %q", netconf)
+	}
+	if err != nil {
+		return fmt.Errorf("error generating interfaces: %w", err)
+	}
+
+	if err := initialize.ApplyNetworkConfig(ifaces, env); err != nil {
+		return fmt.Errorf("error applying network config: %w", err)
+	}
+	return nil
+}
+
 // mergeConfigs merges certain options from md (meta-data from the datasource)
 // onto cc (a CloudConfig derived from user-data), if they are not already set
 // on cc (i.e. user-data always takes precedence)

initialize/config.go

@@ -15,7 +15,6 @@
 package initialize
 
 import (
-	"errors"
 	"fmt"
 	"log"
 	"path"
@@ -39,10 +38,29 @@ type CloudConfigUnit interface {
 	Units() []system.Unit
 }
 
+// ApplyNetworkConfig creates networkd units for the given interfaces, reloads systemd
+// and restarts networkd.
+func ApplyNetworkConfig(ifaces []network.InterfaceGenerator, env *Environment) error {
+	if len(ifaces) == 0 {
+		return nil
+	}
+	units := createNetworkingUnits(ifaces)
+
+	um := system.NewUnitManager(env.Root())
+	if err := processUnits(units, env.Root(), um); err != nil {
+		return fmt.Errorf("error processing network units: %w", err)
+	}
+
+	if err := system.RestartNetwork(ifaces); err != nil {
+		return fmt.Errorf("error restarting networkd: %w", err)
+	}
+	return nil
+}
+
 // Apply renders a CloudConfig to an Environment. This can involve things like
 // configuring the hostname, adding new users, writing various configuration
 // files to disk, and manipulating systemd services.
-func Apply(cfg config.CloudConfig, ifaces []network.InterfaceGenerator, env *Environment) error {
+func Apply(cfg config.CloudConfig, env *Environment) error {
 	if cfg.Hostname != "" {
 		if err := system.SetHostname(cfg.Hostname); err != nil {
 			return err
@@ -166,13 +184,6 @@ func Apply(cfg config.CloudConfig, ifaces []network.InterfaceGenerator, env *Env
 		}
 	}
 
-	if len(ifaces) > 0 {
-		units = append(units, createNetworkingUnits(ifaces)...)
-		if err := system.RestartNetwork(ifaces); err != nil {
-			return err
-		}
-	}
-
 	um := system.NewUnitManager(env.Root())
 	return processUnits(units, env.Root(), um)
 }
@@ -267,7 +278,7 @@ func processUnits(units []system.Unit, root string, um system.UnitManager) error
 
 	if reload {
 		if err := um.DaemonReload(); err != nil {
-			return errors.New(fmt.Sprintf("failed systemd daemon-reload: %s", err))
+			return fmt.Errorf("failed systemd daemon-reload: %w", err)
 		}
 	}