[services-openrc] Simplify name extraction, default runlevel

- If runlevel isn't set (at all) then use "default". For
   most systems that do not use multiple runlevels, this
   simplifies the configuration to just a list of service names
   to add or delete.

src/modules/services-openrc/main.py

@@ -48,15 +48,18 @@ class OpenrcController:
         """
 
         for svc in self.services.get(state, []):
-            service_path = self.root + self.initdDir + "/" + svc["name"]
-            runlevel_path = self.root + self.runlevelsDir + "/" + svc["runlevel"]
+            name = svc["name"]
+            runlevel = svc.get("runlevel", "default")
+
+            service_path = self.root + self.initdDir + "/" + name
+            runlevel_path = self.root + self.runlevelsDir + "/" + runlevel
             if exists(service_path):
                 if exists(runlevel_path):
-                    target_env_call(["rc-update", state, svc["name"], svc["runlevel"]])
+                    target_env_call(["rc-update", state, name, runlevel])
                 else:
-                    warning("Target runlevel {} does not exist for {}.".format(svc["runlevel"], svc["name"]))
+                    warning("Target runlevel {} does not exist for {}.".format(runlevel, name))
             else:
-                warning("Target service {} does not exist int {}.".format(svc["name"], self.initDir))
+                warning("Target service {} does not exist int {}.".format(name, self.initDir))
 
 
     def run(self):

src/modules/services-openrc/services-openrc.conf

@@ -18,13 +18,16 @@ runlevelsDir: /etc/runlevels
 # has a list of entries as value, and each entry has two
 # fields:
 #   - name: the service name
-#   - runlevel: can hold any runlevel present on the target system
+#   - runlevel: can hold any runlevel present on the target system;
+#     if no runlevel is provided, "default" is assumed.
 #
 # # Example services:
+# # - add foo1 to default
+# # - add foo2 to nonetwork
+# # - remove foo3 from default
 # services:
 #     add:
 #         - name: foo1
-#           runlevel: default
 #         - name: foo2
 #           runlevel: nonetwork
 #     del: