Convert nextcloud db to postgres

ansible/roles/docker/files/nextcloud/docker-compose.yml

@@ -24,19 +24,14 @@ services:
       - "traefik.http.routers.nextcloud.tls=true"
       - "traefik.http.routers.nextcloud.tls.certresolver=le"
 
-  mariadb:
-    image: linuxserver/mariadb:110.4.12mariabionic-ls53
-    environment:
-      - PUID={{ docker_user.id }}
-      - PGID={{ docker_user.id }}
-      - MYSQL_ROOT_PASSWORD=root
-      - TZ=Europe/London
-      - MYSQL_DATABASE=nextcloud
-      - MYSQL_USER=nextcloud
-      - MYSQL_PASSWORD=nextcloud
-    volumes:
-      - /srv/nextcloud-mariadb:/config
+  db:
+    image: postgres:12-alpine
     restart: unless-stopped
+    volumes:
+      - ./postgres:/var/lib/postgresql/data
+    environment:
+      - POSTGRES_PASSWORD=nextcloud
+      - POSTGRES_USER=nextcloud
 
   redis:
     image: redis:5-alpine