[train-only] container_systemd: clean and test requires for systemd

Clean some old functions and test the healthcheck dependencies on their
units.

This adds a test case in molecule where we:

- Stop a service and check its healthcheck is also stopped by systemd.
- Start a service and check its healthcheck is also started by systemd.

Change-Id: I5e759d1fed4fe1f7bc2b542d0981e5ce9531d463

tripleo_ansible/ansible_plugins/action/container_systemd.py

@@ -266,27 +266,25 @@ class ActionModule(ActionBase):
         if results.get('changed', False):
             self.changed = True
 
-    def _add_systemd_requires(self, services, task_vars):
+    def _add_systemd_requires(self, services):
         """Add systemd dependencies for healthchecks.
 
         :param services: List for service names.
-        :param task_vars: Dictionary of Ansible task variables.
         """
         for name in services:
             service = 'tripleo_{}'.format(name)
-            if self.debug:
-                DISPLAY.display('Adding systemd dependency for '
-                                '{}'.format(service))
-
             command = ('systemctl add-requires {}.service '.format(service)
                        + '{}_healthcheck.timer'.format(service))
-            results = self._execute_module(
-                module_name='command',
-                module_args=dict(cmd=command),
-                task_vars=task_vars
+            if self.debug:
+                DISPLAY.display('Adding systemd dependency for '
+                                '{} with command: '
+                                '{}'.format(service, command))
+            results = self._low_level_execute_command(
+                command,
+                executable='/bin/bash'
             )
-            if results.get('changed', False):
-                self.changed = True
+            if results.get('rc', 0) != 0:
+                raise AnsibleActionFail('Failed to run {}'.format(command))
 
     @tenacity.retry(
         reraise=True,
@@ -347,15 +345,6 @@ class ActionModule(ActionBase):
             self._manage_service(name=name, state='started',
                                  extension=extension, task_vars=task_vars)
 
-    def _add_requires(self, services, task_vars):
-        """Add systemd requires for healthchecks.
-
-        :param services: List of services to manage.
-        """
-        for s in services:
-            # TODO
-            pass
-
     def run(self, tmp=None, task_vars=None):
         self.changed = False
         self.restarted = []
@@ -414,8 +403,7 @@ class ActionModule(ActionBase):
                 self._ensure_started(service_names=h_already_created,
                                      extension='timer',
                                      task_vars=task_vars)
-            requires_healthchecks = changed_healthchecks + h_already_created
-            self._add_systemd_requires(requires_healthchecks, task_vars)
+            self._add_systemd_requires(all_healthchecks)
 
         result['changed'] = self.changed
         result['restarted'] = self.restarted

tripleo_ansible/roles/tripleo-container-manage/molecule/default/playbook.yml

@@ -107,6 +107,52 @@
             fail_msg: 'fedora_three container has wrong image'
             success_msg: 'fedora_three container has the right image'
 
+- name: Test systemd healthcheck dependency on service
+  become: true
+  hosts: all
+  gather_facts: false
+  tasks:
+    - name: Stop systemd service for tripleo_fedora
+      systemd:
+        name: tripleo_fedora.service
+        state: stopped
+        enabled: true
+    - name: Check if tripleo_fedora_healthcheck timer is active
+      command: systemctl is-active --quiet tripleo_fedora_healthcheck.timer
+      register: tripleo_fedora_healthcheck_active_result
+      failed_when: false
+      when:
+        - not ansible_check_mode|bool
+    - name: Assert that tripleo_fedora_healthcheck timer service is not active
+      assert:
+        that:
+          - tripleo_fedora_healthcheck_active_result.rc == 3
+        fail_msg: 'tripleo_fedora systemd service is active'
+        success_msg: 'tripleo_fedora systemd service is not active'
+      when:
+        - not ansible_check_mode|bool
+    - name: Start systemd service for tripleo_fedora
+      systemd:
+        name: tripleo_fedora.service
+        state: started
+        enabled: true
+    - name: Check if tripleo_fedora_healthcheck timer is active
+      command: systemctl is-active --quiet tripleo_fedora_healthcheck.timer
+      register: tripleo_fedora_healthcheck_active_result
+      until: tripleo_fedora_healthcheck_active_result.rc == 0
+      retries: 5
+      delay: 5
+      when:
+        - not ansible_check_mode|bool
+    - name: Assert that tripleo_fedora_healthcheck timer service is active
+      assert:
+        that:
+          - tripleo_fedora_healthcheck_active_result.rc == 0
+        fail_msg: 'tripleo_fedora systemd service is not active'
+        success_msg: 'tripleo_fedora systemd service is active'
+      when:
+        - not ansible_check_mode|bool
+
 - name: Test idempotency on fedora container
   become: true
   hosts: all