roles: Inherit from global vars with defaults

Global options such as 'timezone' or 'puid' can be set on a host and all
(relevant) roles will inherit them. Will be used for more variables in
the future.

group_vars/instance_system/vars.yaml

@@ -1,4 +1,5 @@
-arrstack_tz: Europe/Berlin
-stack_paperless_tz: Europe/Berlin
+---
+
+timezone: Europe/Berlin
 stack_paperless_ocr_language: deu+eng
 stack_paperless_ocr_languages: eng deu frk

roles/arr/defaults/main.yml

@@ -1,14 +1,16 @@
 ---
 
-arrstack_env_dir: /opt/arrstack
+# inherited from global
+arrstack_tz: "{{ timezone | default('America/Chicago') }}"
+arrstack_puid: "{{ puid | default(1000) }}"
+arrstack_pgid: "{{ pgid | default(100) }}"
+arrstack_umask_set: "{{ umask_set | default(022) }}"
 
+arrstack_env_dir: /opt/arrstack
 arrstack_serve_dir: /srv
 arrstack_serve_dir_create: true
 
-arrstack_puid: 1000
-arrstack_pgid: 100
-arrstack_tz: America/Chicago
-arrstack_umask_set: 022
-
 # arrstack_mb_user: Musicbrainz-user
 # arrstack_mb_pass: Musicbrainz-password
+
+# TODO: add commented version of remaining required vars (qbit, vpn)

roles/grocy/defaults/main.yml

@@ -1,8 +1,9 @@
 ---
+# inherited from global
+stack_grocy_tz: "{{ timezone | default('America/Chicago') }}"
+stack_grocy_puid: "{{ puid | default(1000) }}"
+stack_grocy_pgid: "{{ pgid | default(100) }}"
+stack_grocy_umask_set: "{{ umask_set | default(022) }}"
 
 stack_grocy_env_dir: /opt/stack_grocy
 
-stack_grocy_puid: 1000
-stack_grocy_pgid: 100
-stack_grocy_tz: America/Chicago
-stack_grocy_umask_set: 022

roles/paperless/defaults/main.yml

@@ -1,13 +1,14 @@
 ---
 
-stack_paperless_env_dir: /opt/stack_paperless
-stack_paperless_puid: 1000
-stack_paperless_pgid: 100
+# inherited from global
+stack_paperless_tz: "{{ timezone | default('America/Chicago') }}"
+stack_paperless_puid: "{{ puid | default(1000) }}"
+stack_paperless_pgid: "{{ pgid | default(100) }}"
 
+stack_paperless_env_dir: /opt/stack_paperless
 stack_paperless_serve_dir: /srv
 stack_paperless_serve_dir_create: true
 
-stack_paperless_tz: America/Chicago
 stack_paperless_ocr_language: eng # default OCR languages
 stack_paperless_ocr_languages: eng deu frk # ALL installed languages
 stack_paperless_ocr_skip_archive_file: with_text