Custom postgres entrypoint to handle major upgrades..

..appropriated from the coop-cloud/outline recipe.

compose.yml

@@ -30,9 +30,15 @@ services:
         - "traefik.http.routers.${STACK_NAME}.tls.certresolver=${LETS_ENCRYPT_ENV}"
         - coop-cloud.${STACK_NAME}.version=1.1.0+1.5.1
   db:
-    image: postgres:13.11-alpine
+    image: postgres:13.11
+    configs:
+      - source: db_entrypoint
+        target: /docker-entrypoint.sh
+        mode: 0555
+    # Custom docker entrypoint to handle major Postgres version upgrades
     volumes:
       - db-data:/var/lib/postgresql/data
+    entrypoint: /docker-entrypoint.sh
     environment:
       - POSTGRES_USER=plausible
       - POSTGRES_PASSWORD=plausible
@@ -68,3 +74,7 @@ configs:
   clickhouse-user-config:
     name: ${STACK_NAME}_clickhouse_user_config_${CLICKHOUSE_USER_CONF_VERSION}
     file: clickhouse-user-config.xml
+  db_entrypoint:
+    name: ${STACK_NAME}_db_entrypoint_${DB_ENTRYPOINT_VERSION}
+    file: entrypoint.postgres.sh.tmpl
+    template_driver: golang