Add possibility to configure systemd sockets

We need to be able to configure systemd-sockets. Since they are attached
to the service it make sense to make it as an element to the service.

Change-Id: Ic481921151fc8d7af7f1ca9b003adb8e3c967e16

defaults/main.yml

@@ -111,6 +111,16 @@ systemd_environment: {}
 #  `dynamic_user` -- (optional) Dynamically set a UNIX user and group when the unit is started; only works if systemd >= 235.
 #  `state_directory` -- (optional) Relative path the state directory; only works if systemd >= 235.
 
+# Under the service dictionary the "sockets" key can be added, which may contain list of the sockets
+#  for the given service_name. Each socket in the lsit may have following structure:
+#  `socket_name` -- (required) Name of created socket
+#  `after_targets` -- (optional) Start the socket after this list of dependency units.
+#  `before_targets` -- (optional) Start the socket before this list of dependency units.
+#  `bind_targets` -- (optional) Bind the socket to this dependency unit.
+#  `enabled` -- (optional) Set the enabled state of the socket.
+#  `options` -- (optional) Additional options, like `ListenStream` or other
+#  `state` -- (optional) Set the running state of the socket.
+
 # Under the service dictionary the "timer" key can be added which will enable a given service
 #  as a timer (Legacy cron job).
 #  `options` -- (optional) This allows any section or key=value pair to be set within the systemd timer file.
@@ -170,6 +180,19 @@ systemd_environment: {}
 #       execstops
 #         - /usr/bin/stopcmd1
 #         - /usr/bin/stopcmd2
+#       sockets:
+#         - socket_name: SocketServiceZ
+#           after_targets:
+#             - ServiceZ.socket
+#           before_targets:
+#             - ServiceY.service
+#           bind_targets:
+#             - ServiceZ.socket
+#           enabled: true
+#           state: started
+#           options:
+#             SocketMode: 0600
+#             ListenStream: /var/run/ServiceZ
 #
 #     - service_name: TimerServiceW
 #       config_overrides: {}  # This is used to add in arbitratry unit file options

releasenotes/notes/systemd_socket-288b17560a578814.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    Added sockets key to configure systemd-sockets for the systemd service.

tasks/main.yml

@@ -107,11 +107,25 @@
   tags:
     - systemd-service
 
+- name: Place the systemd socket
+  template:
+    src: "systemd-socket.j2"
+    dest: "/etc/systemd/system/{{ item.1.socket_name | replace(' ', '_') }}.socket"
+    mode: "0644"
+    owner: "root"
+    group: "root"
+  loop: "{{ systemd_services | subelements('sockets', skip_missing=True) }}"
+  notify:
+    - systemd service changed
+  register: systemd_socket
+  tags:
+    - systemd-service
+
 - name: Reload systemd on unit change
   systemd:
     daemon_reload: yes
   when:
-    - (systemd_services_result is changed) or (systemd_timer_result is changed)
+    - (systemd_services_result is changed) or (systemd_timer_result is changed) or ('true' in systemd_socket.results | map(attribute='changed') | list )
 
 - name: Load service
   systemd:
@@ -132,3 +146,12 @@
   with_items: "{{ systemd_services }}"
   tags:
     - systemd-service
+
+- name: Load socket
+  systemd:
+    name: "{{ item.socket_name | replace(' ', '_') }}.socket"
+    enabled: "{{ item.enabled | default(systemd_service_enabled) }}"
+    state: "{{ item.state | default(omit) }}"
+  loop: "{{ systemd_services | selectattr('sockets', 'defined') | map(attribute='sockets') | flatten(1) }}"
+  tags:
+    - systemd-service

templates/systemd-socket.j2

@@ -0,0 +1,22 @@
+# {{ ansible_managed }}
+
+[Unit]
+Description={{ item.1.socket_name }} socket
+{% for target in item.1.after_targets | default([]) %}
+After={{ target }}
+{% endfor %}
+{% for target in item.1.before_targets | default([]) %}
+Before={{ target }}
+{% endfor %}
+{% for target in item.1.bind_targets | default([]) %}
+BindsTo={{ target }}
+{% endfor %}
+
+[Socket]
+Service={{ item.0.service_name | replace(' ', '_') }}.service
+{% for key, var in item.1.options.items() | default({}) %}
+{{ key }}={{ var }}
+{% endfor %}
+
+[Install]
+WantedBy=sockets.target