added new defaults and generalized functionality

plugins/module_utils/module.py

@@ -1,14 +1,12 @@
 import pathlib
-from typing import (Any, Callable, ClassVar, Dict, NoReturn, Optional, TypeVar,
-                    overload)
+from typing import Any, Callable, ClassVar, Dict, NoReturn, Optional, Type, TypeVar, overload
 
 import ansible.module_utils.basic as basic
 
 try:
-    from ansible_collections.sebastian.systemd.plugins.module_utils.generic import \
-        _sdict
+    from ansible_collections.sebastian.systemd.plugins.module_utils.generic import Types, _sdict
 except ImportError:
-    from plugins.module_utils.generic import _sdict
+    from plugins.module_utils.generic import Types, _sdict
 
 __all__ = (
     "AnsibleModule",
@@ -183,6 +181,21 @@ class SystemdUnitModule(AnsibleModule):
     _common_args = dict(
         supports_check_mode=True,
         add_file_common_args=True,
+        argument_spec=dict(
+            description=Types.str(help="An description for programs that access systemd"),
+            documentation=Types.list(str, help="Paths where documentation can be found"),
+            requires=Types.list(
+                str,
+                help="list of units that this unit requires. If it fails or can't be started this unit fails. without before/after this is started at the same time",
+            ),
+            wants=Types.list(str, help="list of units that this unit wants. If it fails or can't be started it does not affect this unit"),
+            partof=Types.list(
+                str,
+                help="list of units that this unit is part of.\nIf the restart this unit does it too, but if this restarts it does not affect the other units.",
+            ),
+            before=Types.list(str, help="list of units that this unit needs to be started before this unit."),
+            after=Types.list(str, help="list of units that this unit wants to be started after this unit"),
+        ),
     )
     #: if defined it will be called after run has changed the unitfile
     post: Optional[Callable[[], None]]
@@ -190,6 +203,24 @@ class SystemdUnitModule(AnsibleModule):
     def unit(self) -> str:
         raise NotImplementedError()
 
+    def header(self) -> str:
+        header = "[Unit]\n"
+        if self.get("description", False):
+            header += "Description={}\n".format(self.get("description"))
+        if self.get("documentation", False):
+            header += "Documentation={}\n".format(" ".join(self.get("documentation")))
+        if self.get("requires", False):
+            header += "Requires={}\n".format(" ".join(self.get("requires")))
+        if self.get("wants", False):
+            header += "Wants={}\n".format(" ".join(self.get("wants")))
+        if self.get("partof", False):
+            header += "PartOf={}\n".format(" ".join(self.get("partof")))
+        if self.get("before", False):
+            header += "Before={}\n".format(" ".join(self.get("before")))
+        if self.get("after", False):
+            header += "After={}\n".format(" ".join(self.get("after")))
+        return header
+
     def unitfile_gen(self):
         path = self.tmpdir / "newunit"
         with open(path, "w") as unit:
@@ -251,3 +282,32 @@ class SystemdUnitModule(AnsibleModule):
         )
         if hasattr(self, "post") and self.post is not None:
             self.post()
+
+
+_INSTALL_MAPPING = dict(
+    required_by="RequiredBy",
+    wanted_by="WantedBy",
+)
+
+
+def installable(_class: Type[SystemdUnitModule]):
+    """adds the required arguments to the spec and adds the install method for the unit method"""
+    arguments = dict(
+        required_by=Types.list(elements=str, help="systemd units that require this mount"),
+        wanted_by=Types.list(
+            elements=str,
+            help="systemd units that want the mount, but not explicitly require it. Commonly used for target if not service explicitly require it.",
+        ),
+    )
+    _class.module_spec["argument_spec"].update(arguments)
+
+    def install(self: SystemdUnitModule) -> str:
+        output = "[Install]\n"
+        for argument, key in _INSTALL_MAPPING.items():
+            if self.get(argument, False):
+                for unit in self.get(argument):
+                    output += "{}={}\n".format(key, unit)
+        return output
+
+    _class.install = install
+    return _class