Merge branch 'archwiki-cache-invalidation' into 'master'

archwiki: ensure that MediaWiki file cache is invalidated on each MediaWiki update

See merge request !490

roles/archwiki/handlers/main.yml

@@ -15,3 +15,12 @@
 # reference: https://stackoverflow.com/a/6896903
 - name: purge nginx cache
   command: find /var/lib/nginx/cache -type f -delete
+
+# The MediaWiki file cache can be invalidated by deleting the files in the
+# cache, by setting $wgCacheEpoch to the current time, or by touching the
+# LocalSettings.php file (thanks to $wgInvalidateCacheOnLocalSettingsChange
+# being set to true). References:
+# - https://www.mediawiki.org/wiki/Manual:File_cache
+# - https://www.mediawiki.org/wiki/Manual:$wgInvalidateCacheOnLocalSettingsChange
+- name: invalidate MediaWiki file cache
+  file: path="{{ archwiki_dir }}/public/LocalSettings.php" state=touch

roles/archwiki/tasks/main.yml

@@ -42,9 +42,6 @@
   when: maintenance is not defined
   tags: ['nginx']
 
-- name: remove old fastcgi cache directory
-  file: path=/etc/nginx/wikicache state=absent
-
 - name: configure robots.txt
   copy: src=robots.txt dest="{{ archwiki_dir }}/robots.txt" owner=root group=root mode=0644
 
@@ -60,8 +57,10 @@
   become_user: "{{ archwiki_user }}"
   notify:
     - run wiki updatescript
-    # purge the nginx cache to make sure clients get the updated assets
+    # purge the nginx cache and MediaWiki file cache to make sure clients get updated assets
+    # as well as freshly rendered pages using the new assets
     - purge nginx cache
+    - invalidate MediaWiki file cache
 
 - name: configure archwiki
   template: src=LocalSettings.php.j2 dest="{{ archwiki_dir }}/public/LocalSettings.php" owner="{{ archwiki_user }}" group="{{ archwiki_user }}" mode=0640