More flexible cgroup settings (#352)

* More flexible cgroup settings

If there are already required cgroup boot parameters present but in a
different order than specified, the script will add them again. It is
better to test for the individual parameter in a loop and selectively
add them as necessary.

Signed-off-by: Marko Vukovic <anonsoftware@gmail.com>

Signed-off-by: Marko Vukovic <anonsoftware@gmail.com>
Signed-off-by: Marko Vukovic <8951449+anon-software@users.noreply.github.com>

roles/raspberrypi/tasks/prereq/Ubuntu.yml

@@ -1,11 +1,16 @@
 ---
 - name: Enable cgroup via boot commandline if not already enabled
   when: lookup('fileglob', '/boot/firmware/cmdline.txt', errors='warn') | length > 0
-  ansible.builtin.lineinfile:
+  ansible.builtin.replace:
     path: /boot/firmware/cmdline.txt
-    backrefs: true
-    regexp: '^((?!.*\bcgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory\b).*)$'
-    line: '\1 cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory'
+    regexp: '^([\w](?!.*\b{{ cgroup_item }}\b).*)$'
+    replace: '\1 {{ cgroup_item }}'
+  with_items:
+    - "cgroup_enable=cpuset"
+    - "cgroup_memory=1"
+    - "cgroup_enable=memory"
+  loop_control:
+    loop_var: cgroup_item
   notify: Reboot Pi
 
 - name: Install Ubuntu Raspi Extra Packages