Add suggested fix for offline message in cockpit

roles/cockpit/files/10-globally-managed-devices.conf

@@ -0,0 +1,2 @@
+[keyfile]
+unmanaged-devices=none

roles/cockpit/tasks/main.yml

@@ -30,6 +30,20 @@
     group: root
     mode: 0644
 
+# https://cockpit-project.org/faq.html#error-message-about-being-offline
+- name: Allow NetworkManager to manage network interfaces
+  become_user: root
+  become: true
+  ansible.builtin.copy:
+    src: files/10-globally-managed-devices.conf
+    dest: /etc/NetworkManager/conf.d/
+    owner: root
+    group: root
+    mode: "0644"
+
+- name: Set-up a dummy network interface faking internet connection
+  ansible.builtin.command: "nmcli con add type dummy con-name fake ifname fake0 ip4 1.2.3.4/24 gw4 1.2.3.1"
+
 - name: Permit traffic from any IP to cockpit socket
   become: true
   community.general.ufw: