use lineinfile

roles/moodle/tasks/install.yml

@@ -139,6 +139,8 @@
     mode: 0644
 
 - name: Add 'moodle_installed' variable values to {{ iiab_installed }}
-  ini_file:
-    path: "{{ iiab_installed }}"
-    value: moodle_installed
+  lineinfile:
+    dest: "{{ iiab_installed }}"
+    regexp: '^moodle_installed'
+    line: 'moodle_installed'
+    state: present

roles/moodle/tasks/main.yml

@@ -2,6 +2,6 @@
   include_tasks: install.yml
   when: moodle_install | bool and not moodle_installed is defined
 
-- name: Enable Moodle 
+- name: Enable Moodle
   include_tasks: enable.yml
   when: moodle_install | bool or moodle_installed is defined