docs: Added docs for systemd interfaces

docs/proxies.rst

@@ -263,4 +263,214 @@ for more details.
         * 3 - notification was closed by call to :py:meth:`close_notification`
         * 4 - undefined/reserved reasons.
 
+Systemd Manager
++++++++++++++++++++++++++++++++++++++
+
+Systemd state manager.
+
+This interface is not finished and only has a limited subset of methods and properties.
+
+.. py:class:: SystemdManager
+
+    .. py:method:: __init__([bus])
+
+        Dbus interface object path and service name is
+        predetermined.
+        (at ``'org.freedesktop.systemd1'``,
+        ``'/org/freedesktop/systemd1'``)
+
+        :param SdBus bus:
+            Optional dbus connection.
+            If not passed the default dbus will be used.
+
+    .. py:method:: list_units()
+        :async:
+
+        Lists units.
+
+        This function is not recommended as the output is hard to use.
+        See :py:meth:`SystemdManager.list_units_named` .
+
+        :returns: List of unit data.
+        :rtype: List[Tuple[str, str, str, str, str, str, str, int, str, str]]
+
+    .. py:method:: list_units_named()
+
+        Async iterator over unit data in named tuples.
+
+        Named tuple has following definition: ::
+
+            class SystemdUnitListTuple(NamedTuple):
+                primary_name: str
+                description: str
+                load_state: str
+                active_state: str
+                sub_state: str
+                followed_unit: str
+                unit_path: str
+                job_id: int
+                job_type: str
+                job_path: str
+
+        :returns: Async iterator over unit data.
+        :rtype: SystemdUnitListTuple
+
+    .. py:method:: subscribe()
+
+        Enables signals.
+
+        :rtype: None
+
+    .. py:method:: unsubscribe()
+
+        Disables signals.
+
+        :rtype: None
+
+    .. py:attribute:: version
+        :type: str
+
+        Systemd version.
+
+    .. py:attribute:: unit_new
+        :type: Tuple[str, str]
+
+        Signal when new systemd unit loads in to memory.
+        Data is unit name and dbus path. 
+
+        This signal **only works** after :py:meth:`SystemdManager.subscribe` had been called.
+
+    .. py:attribute:: unit_removed
+        :type: Tuple[str, str]
+
+        Signal when new systemd unit removed from memory.
+        Data is unit name and dbus path.
+
+        This signal **only works** after :py:meth:`SystemdManager.subscribe` had been called.
+
+Systemd Unit
++++++++++++++++++++++++++++++++++++++
+
+Systemd unit.
+
+This interface is not finished and only has a limited subset of methods and properties.
+
+.. py:class:: SystemdUnit
+
+    .. py:method:: __init__(unit_name, [bus])
+
+        Create object representing systemd unit.
+        Unit name should be passed in full.
+
+        Example: ``'dbus.service'`` is dbus daemon service.
+
+        :param str unit_name: Systemd unit name. 
+        :param SdBus bus:
+            Optional dbus connection.
+            If not passed the default dbus will be used.
+
+    .. py:method:: freeze()
+        :async:
+
+        Freeze unit. See systemd documentation.
+
+    .. py:method:: thaw()
+        :async:
+
+        Thaw unit. See systemd documentation.
+
+    .. py:method:: kill(kill_who, signal)
+        :async:
+
+        Send a signal to a processes of a unit.
+
+        :param str kill_who: Who to send signal.
+            Possible values:
+
+            * ``'main'`` - main process of the unit
+            * ``'control'`` - control process
+            * ``'all'`` - all processes
+
+        :param int signal: Signal to use.
+
+    .. py:method:: start(mode)
+
+        Start unit.
+
+        :param str mode: Start mode of the unit.
+            One of:
+
+            * ``'replace'``
+            * ``'fail'``
+            * ``'isolate'``
+            * ``'ignore-dependencies'``
+            * ``'ignore-requirements'``
+
+    .. py:method:: restart(mode)
+
+        Restart unit.
+
+        :param str mode: See :py:meth:`SystemdUnit.start`
+
+    .. py:method:: stop(mode)
+
+        Stop unit.
+
+        :param str mode: See :py:meth:`SystemdUnit.start` except `'isolate'`.
+
+    .. py:method:: reload(mode)
+
+        Reload unit. Only works if unit is already running.
+
+        :param str mode: See :py:meth:`SystemdUnit.start`
+
+    .. py:method:: reload_or_restart(mode)
+
+        Restart or reload unit.
+
+        :param str mode: See :py:meth:`SystemdUnit.start`
+
+    .. py:method:: reload_or_try_restart(mode)
+
+        Restart or reload unit.
+
+        :param str mode: See :py:meth:`SystemdUnit.start`
+
+    .. py:method:: try_restart(mode)
+
+        Try restart unit.
+
+        :param str mode: See :py:meth:`SystemdUnit.start`
+
+    .. py:method:: reset_failed(mode)
+
+        Reset 'failed' status
+
+    .. py:method:: set_properties(is_runtime, properties)
+
+        Sets the unit properties.
+
+        Can either be at runtime or permanent.
+
+        :param bool is_runtime: Runtime or permanent.
+
+    .. py:attribute:: active_state
+        :type: str
+
+        Current state of the unit:
+
+        One of:
+
+        * ``'active'``
+        * ``'reloading'``
+        * ``'inactive'``
+        * ``'failed'``
+        * ``'activating'``
+        * ``'deactivating'``
+
+    .. py:attribute:: sub_state
+        :type: str
+
+        Unit type specific state.
 
+        For example, service unit can be ``'running'``.