Refactoring, extract functions

main.go

@@ -97,13 +97,7 @@ func removeConnection(conn *dbus.Conn, connPath dbus.ObjectPath) error {
 	return nil
 }
 
-func main() {
-	if len(os.Args) < 3 {
-		usage()
-	}
-	iface := os.Args[1]
-	op := os.Args[2]
-
+func getSettings(op string) (string, string) {
 	// Get SSID and password from args, env vars or use defaults
 	ssid := defaultSSID
 	password := defaultPassword
@@ -122,12 +116,10 @@ func main() {
 		password = os.Args[4]
 	}
 
-	// Connect to the system bus
-	conn, err := dbus.SystemBus()
-	if err != nil {
-		log.Fatalf("Failed to connect to system bus: %v", err)
+	return ssid, password
 }
 
+func getConnectionPath(conn *dbus.Conn, connUUID string) (dbus.ObjectPath, error) {
 	// Get the Settings interface
 	settingsObj := conn.Object(
 		"org.freedesktop.NetworkManager",
@@ -136,11 +128,11 @@ func main() {
 
 	// List existing connections
 	var paths []dbus.ObjectPath
-	err = settingsObj.
+	err := settingsObj.
 		Call("org.freedesktop.NetworkManager.Settings.ListConnections", 0).
 		Store(&paths)
 	if err != nil {
-		log.Fatalf("ListConnections failed: %v", err)
+		return "", fmt.Errorf("ListConnections failed: %v", err)
 	}
 
 	// Look up our connection by UUID
@@ -157,14 +149,21 @@ func main() {
 		if err != nil {
 			continue
 		}
-		if v, ok := cfg["connection"]["uuid"].Value().(string); ok && v == ourUUID {
+		if v, ok := cfg["connection"]["uuid"].Value().(string); ok && v == connUUID {
 			connPath = p
 			break
 		}
 	}
 
-	// If not found, add it
-	if connPath == "" {
+	return connPath, nil
+}
+
+func addConnection(conn *dbus.Conn, ssid string, password string) (dbus.ObjectPath, error) {
+	settingsObj := conn.Object(
+		"org.freedesktop.NetworkManager",
+		"/org/freedesktop/NetworkManager/Settings",
+	)
+
 	settingsMap := map[string]map[string]dbus.Variant{
 		"connection": {
 			"type":        dbus.MakeVariant("802-11-wireless"),
@@ -190,14 +189,18 @@ func main() {
 		},
 	}
 
-		err = settingsObj.
+	var connPath dbus.ObjectPath
+	err := settingsObj.
 		Call("org.freedesktop.NetworkManager.Settings.AddConnection", 0, settingsMap).
 		Store(&connPath)
 	if err != nil {
-			log.Fatalf("AddConnection failed: %v", err)
-		}
+		return "", fmt.Errorf("AddConnection failed: %v", err)
 	}
 
+	return connPath, nil
+}
+
+func getDevicePath(conn *dbus.Conn, iface string) (dbus.ObjectPath, error) {
 	// Get the NetworkManager interface
 	nmObj := conn.Object(
 		"org.freedesktop.NetworkManager",
@@ -206,11 +209,46 @@ func main() {
 
 	// Find the device by interface name
 	var devPath dbus.ObjectPath
-	err = nmObj.
+	err := nmObj.
 		Call("org.freedesktop.NetworkManager.GetDeviceByIpIface", 0, iface).
 		Store(&devPath)
 	if err != nil {
-		log.Fatalf("GetDeviceByIpIface(%s) failed: %v", iface, err)
+		return "", fmt.Errorf("GetDeviceByIpIface(%s) failed: %v", iface, err)
+	}
+
+	return devPath, nil
+}
+
+func main() {
+	if len(os.Args) < 3 {
+		usage()
+	}
+	iface := os.Args[1]
+	op := os.Args[2]
+
+	ssid, password := getSettings(op)
+
+	// Connect to the system bus
+	conn, err := dbus.SystemBus()
+	if err != nil {
+		log.Fatalf("Failed to connect to system bus: %v", err)
+	}
+
+	connPath, err := getConnectionPath(conn, ourUUID)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	if connPath == "" {
+		connPath, err = addConnection(conn, ssid, password)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	devPath, err := getDevicePath(conn, iface)
+	if err != nil {
+		log.Fatal(err)
 	}
 
 	switch op {