add option to disable ddcci-dkms installation

useful for iMacs with T2 chips

Author: FreekBes

README.md

@@ -52,3 +52,4 @@ It is also possible to specify a default user image in case the user's `~/.face`
 | `dbus_cache_group_check_enabled`| Whether to check if a user is in a specific ldap group before adding it to the dbus cache. Usually this is not required. | `false` |
 | `dbus_cache_group_check_group`| The group to check for. | `student` |
 | `login_wallpaper_path` | The path to the login wallpaper to set. | `/usr/share/42/login-screen.jpg` |
+| `ddcci_backlight_support` | Whether to enable support for DDC/CI to allow controlling the brightness of external monitors. Should be set to `false` if you're using iMacs with T2 chips or any other *ddcci-dkms* unsupported kernel. | `true` |

defaults/main.yml

@@ -17,3 +17,7 @@ dbus_cache_group_check_enabled: false
 dbus_cache_group_check_group: "student" # default ou=student,ou=groups,dc=42campus,dc=org
 
 login_wallpaper_path: "/usr/share/42/login-screen.jpg"
+
+# Specify whether or not to add support for ddcci-backlight control on external monitors
+# Requires ddcci-dkms to be installed, which is not supported by iMacs with T2 chips
+ddcci_backlight_support: true

tasks/init.yml

@@ -15,16 +15,39 @@
   with_items:
     - light-locker # For locking the screen
     - xprintidle # For detecting idle time of a user
-    - ddcci-dkms # For backlight control on external monitors
   # Assume lightdm, nodejs and npm are already installed by 42.app
 
+- name: Install ddcci-dkms #  For backlight control on external monitors
+  tags: [codam.webgreeter, codam.webgreeter.init]
+  apt:
+    name: ddcci-dkms
+    state: present
+  when: ddcci_backlight_support
+
 - name: Enable ddcci-backlight kernel module
   tags: [codam.webgreeter, codam.webgreeter.init]
   become: true
   modprobe:
     name: ddcci-backlight
     state: present
     persistent: present
+  when: ddcci_backlight_support
+
+- name: Disable ddcci-backlight kernel module
+  tags: [codam.webgreeter, codam.webgreeter.init]
+  become: true
+  modprobe:
+    name: ddcci-backlight
+    state: absent
+    persistent: absent
+  when: not ddcci_backlight_support
+
+- name: Remove ddcci-dkms
+  tags: [codam.webgreeter, codam.webgreeter.init]
+  apt:
+    name: ddcci-dkms
+    state: absent
+  when: not ddcci_backlight_support
 
 - name: Check if xbacklight binary exists
   tags: [codam.webgreeter, codam.webgreeter.init]