store mastodon cache outside of backupable directory

roles/mastodon/tasks/main.yml

@@ -10,11 +10,16 @@
   template:
     src: "{{ role_path }}/templates/docker-compose.yml.j2"
     dest: "{{ service_dir }}/docker-compose.yml"
-- name: Create Mastodon data directory
+- name: Create data directory
   file:
     path: "{{ data_dir }}"
     state: directory
     mode: 0777
+- name: Create cache directory
+  file:
+    path: "{{ service_dir }}/cache"
+    state: directory
+    mode: 0777
 - name: Start Docker Compose
   docker_compose:
     project_src: "{{ service_dir }}"

roles/mastodon/templates/docker-compose.yml.j2

@@ -50,6 +50,7 @@ services:
       - redis
     volumes:
       - {{ data_dir }}/public/system:/mastodon/public/system
+      - {{ service_dir }}/cache:/mastodon/public/system/cache
     labels:
       - traefik.http.routers.mastodon.entrypoints=websecure
       - traefik.http.routers.mastodon.rule=Host(`social.pizzapim.nl`)
@@ -97,6 +98,7 @@ services:
       - default
     volumes:
       - {{ data_dir }}/public/system:/mastodon/public/system
+      - {{ service_dir }}/cache:/mastodon/public/system/cache
     healthcheck:
       test: ['CMD-SHELL', "ps aux | grep '[s]idekiq\ 6' || false"]