Update systemd strategy to not confuse NetworkManager (#77243)

* Update systemd strategy to not confuse NetworkManager. Fixes #76958

* Add tests

changelogs/fragments/76958-hostname-systemd-nm.yaml

@@ -0,0 +1,3 @@
+bugfixes:
+- hostname - Update the systemd strategy in the ``hostname`` module to not interfere with
+  NetworkManager (https://github.com/ansible/ansible/issues/76958)

lib/ansible/modules/hostname.py

@@ -332,15 +332,18 @@ class SystemdStrategy(BaseStrategy):
     def set_permanent_hostname(self, name):
         if len(name) > 64:
             self.module.fail_json(msg="name cannot be longer than 64 characters on systemd servers, try a shorter name")
-        cmd = [self.hostnamectl_cmd, '--pretty', 'set-hostname', name]
-        rc, out, err = self.module.run_command(cmd)
-        if rc != 0:
-            self.module.fail_json(msg="Command failed rc=%d, out=%s, err=%s" % (rc, out, err))
-        cmd = [self.hostnamectl_cmd, '--static', 'set-hostname', name]
+        cmd = [self.hostnamectl_cmd, '--pretty', '--static', 'set-hostname', name]
         rc, out, err = self.module.run_command(cmd)
         if rc != 0:
             self.module.fail_json(msg="Command failed rc=%d, out=%s, err=%s" % (rc, out, err))
 
+    def update_current_and_permanent_hostname(self):
+        # Must set the permanent hostname prior to current to avoid NetworkManager complaints
+        # about setting the hostname outside of NetworkManager
+        self.update_permanent_hostname()
+        self.update_current_hostname()
+        return self.changed
+
 
 class OpenRCStrategy(BaseStrategy):
     """

test/integration/targets/hostname/tasks/test_normal.yml

@@ -1,3 +1,17 @@
+- name: Ensure hostname doesn't confuse NetworkManager
+  when: ansible_os_family == 'RedHat'
+  block:
+    - name: slurp /var/log/messages
+      slurp:
+        path: /var/log/messages
+      become: yes
+      register: messages_before
+
+    - assert:
+        that:
+          - >
+            'current hostname was changed outside NetworkManager' not in messages_before.content|b64decode
+
 - name: Run hostname module for real now
   become: 'yes'
   hostname:
@@ -8,6 +22,20 @@
   command: hostname
   register: current_after_hn2
 
+- name: Ensure hostname doesn't confuse NetworkManager
+  when: ansible_os_family == 'RedHat'
+  block:
+    - name: slurp /var/log/messages
+      slurp:
+        path: /var/log/messages
+      become: yes
+      register: messages_after
+
+    - assert:
+        that:
+          - >
+            'current hostname was changed outside NetworkManager' not in messages_after.content|b64decode
+
 - name: Run hostname again to ensure it does not change
   become: 'yes'
   hostname: