Extend systemctl is-enabled check to handle "enabled-runtime" too. (#77754)

In general the existence of a runtime-enabled unit should not prevent
a persistent enable being set.

Specifically this handles the case where there is an entry in fstab
for a mount point (which is retained to allow manual mount/umount to
take place) and yet a systemd mount unit needs to be deployed to
handle other unit options. There will be a generator-created unit file
which shows the unit as enabled-runtime and the persistent enable of
the mount unit will fail.

Additionally improve the comments and modify the code to use rsplit()
and the "in" notation since "systemctl is-enabled" is documented to
return specific values in the cases of interest.

---------

Signed-off-by: David Greaves <david@dgreaves.com>
Co-authored-by: Abhijeet Kasurde <akasurde@redhat.com>

changelogs/fragments/enabled_runtime.yml

@@ -0,0 +1,3 @@
+---
+bugfixes:
+  - systemd - extend systemctl is-enabled check to handle "enabled-runtime" (https://github.com/ansible/ansible/pull/77754).

lib/ansible/modules/systemd_service.py

@@ -512,11 +512,15 @@ def main():
 
             # check systemctl result or if it is a init script
             if rc == 0:
-                enabled = True
-                # Check if the service is indirect or alias and if out contains exactly 1 line of string 'indirect'/ 'alias' it's disabled
-                if out.splitlines() == ["indirect"] or out.splitlines() == ["alias"]:
+                # https://www.freedesktop.org/software/systemd/man/systemctl.html#is-enabled%20UNIT%E2%80%A6
+                if out.rstrip() in (
+                        "enabled-runtime",  # transiently enabled but we're trying to set a permanent enabled
+                        "indirect",  # We've been asked to enable this unit so do so despite possible reasons
+                                     # that systemctl may have for thinking it's enabled already.
+                        "alias"):  # Let systemd handle the alias as we can't be sure what's needed.
                     enabled = False
-
+                else:
+                    enabled = True
             elif rc == 1:
                 # if not a user or global user service and both init script and unit file exist stdout should have enabled/disabled, otherwise use rc entries
                 if module.params['scope'] == 'system' and \

test/integration/targets/systemd/handlers/main.yml

@@ -10,3 +10,8 @@
   loop:
     - dummy.service
     - dummy.socket
+
+- name: remove enabled-runtime unit file
+  file:
+    path: /etc/systemd/system/baz.service
+    state: absent

test/integration/targets/systemd/tasks/main.yml

@@ -120,3 +120,4 @@
 
 - import_tasks: test_unit_template.yml
 - import_tasks: test_indirect_service.yml
+- import_tasks: test_enabled_runtime.yml

test/integration/targets/systemd/tasks/test_enabled_runtime.yml

@@ -0,0 +1,50 @@
+- name: Copy enabled-runtime service file
+  template:
+    src: baz.service
+    dest: /etc/systemd/system/baz.service
+    owner: root
+    group: root
+    mode: '0644'
+  notify: remove unit file
+
+- name: Reload systemd
+  systemd:
+    daemon_reload: true
+
+- name: Enable the enabled-runtime service using shell command
+  shell: systemctl enable --runtime baz
+
+- name: Enable enabled-runtime service
+  systemd:
+    name: baz.service
+    enabled: true
+  register: baz_test_1
+
+- name: Enable enabled-runtime service again
+  systemd:
+    name: baz.service
+    enabled: true
+  register: baz_test_2
+
+- name: Disable enabled-runtime service
+  systemd:
+    name: baz.service
+    state: stopped
+    enabled: false
+  register: baz_test_3
+
+- name: Disable enabled-runtime service again
+  systemd:
+    name: baz.service
+    enabled: false
+  register: baz_test_4
+
+- name:
+  assert:
+    that:
+      - baz_test_1 is changed
+      - baz_test_1 is success
+      - baz_test_2 is not changed
+      - baz_test_2 is success
+      - baz_test_3 is changed
+      - baz_test_4 is not changed

test/integration/targets/systemd/templates/baz.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=Baz Server
+Documentation=Baz
+
+[Service]
+ExecStart=/bin/yes
+
+[Install]
+WantedBy=default.target