chore: rename postgres service to db

.env.example

@@ -2,7 +2,7 @@
 POSTGRES_DB=theatre_lab
 POSTGRES_USER=theatre_lab
 POSTGRES_PASSWORD=replace-with-a-local-password
-DATABASE_URL=postgresql://theatre_lab:replace-with-a-local-password@postgres:5432/theatre_lab
+DATABASE_URL=postgresql://theatre_lab:replace-with-a-local-password@db:5432/theatre_lab
 DJANGO_SECRET_KEY=replace-with-a-long-random-development-key
 DJANGO_DEBUG=true
 DJANGO_ALLOWED_HOSTS=localhost,127.0.0.1,backend,azionelab.org

README.md

@@ -12,7 +12,7 @@ stores content, and Docker Compose supplies a reproducible local environment.
   Italian fallback content for development when the CMS is unavailable.
 - `nginx/`: reverse-proxy virtual host for `azionelab.org`, routing public requests to
   Astro or Wagtail.
-- `postgres`: persistent CMS database.
+- `db`: persistent PostgreSQL database.
 - Docker volumes: `postgres_data` for the database and `media_data` for uploads.
 
 See [the architecture document](docs/architecture.md),
@@ -91,11 +91,15 @@ The frontend reads `PUBLIC_CMS_API_URL`; inside Compose it defaults to
 public reverse-proxy address. Change both values for another environment.
 The standard published-page endpoint is also available at `/api/v2/pages/`.
 
+The PostgreSQL service is named `db`. Existing `.env` files should replace `@postgres:`
+with `@db:` in `DATABASE_URL`; a compatibility network alias keeps older local values
+working during the transition.
+
 ## Useful commands
 
 ```bash
 # Follow application logs
-docker compose logs -f postgres backend frontend proxy
+docker compose logs -f db backend frontend proxy
 
 # Run database migrations
 docker compose exec backend python manage.py migrate
@@ -137,7 +141,7 @@ Database rows and uploaded files must be backed up together:
 ```bash
 mkdir -p backups/media
 docker compose stop frontend backend
-docker compose exec -T postgres sh -c 'pg_dump -U "$POSTGRES_USER" "$POSTGRES_DB"' > backups/database.sql
+docker compose exec -T db sh -c 'pg_dump -U "$POSTGRES_USER" "$POSTGRES_DB"' > backups/database.sql
 docker compose cp backend:/app/media/. backups/media/
 docker compose start backend frontend
 ```

docker-compose.yml

@@ -1,5 +1,5 @@
 services:
-  postgres:
+  db:
     image: postgres:16.9-alpine
     restart: unless-stopped
     init: true
@@ -9,6 +9,10 @@ services:
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-replace-with-a-local-password}
     volumes:
       - postgres_data:/var/lib/postgresql/data
+    networks:
+      default:
+        aliases:
+          - postgres
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -U $${POSTGRES_USER} -d $${POSTGRES_DB}"]
       interval: 5s
@@ -24,7 +28,7 @@ services:
     restart: unless-stopped
     init: true
     environment:
-      DATABASE_URL: ${DATABASE_URL:-postgresql://theatre_lab:replace-with-a-local-password@postgres:5432/theatre_lab}
+      DATABASE_URL: ${DATABASE_URL:-postgresql://theatre_lab:replace-with-a-local-password@db:5432/theatre_lab}
       DJANGO_SECRET_KEY: ${DJANGO_SECRET_KEY:-replace-with-a-long-random-development-key}
       DJANGO_DEBUG: ${DJANGO_DEBUG:-true}
       DJANGO_ALLOWED_HOSTS: ${DJANGO_ALLOWED_HOSTS:-localhost,127.0.0.1,backend,azionelab.org}
@@ -34,7 +38,7 @@ services:
     ports:
       - "127.0.0.1:8000:8000"
     depends_on:
-      postgres:
+      db:
         condition: service_healthy
     healthcheck:
       test: ["CMD", "python", "-c", "import urllib.request; urllib.request.urlopen('http://localhost:8000/health/', timeout=2)"]

docs/deployment.md

@@ -33,6 +33,10 @@ development.
 `PUBLIC_CMS_API_URL` must be reachable by Astro; within Compose it is
 `http://backend:8000`.
 
+The PostgreSQL Compose service is `db`, so new `DATABASE_URL` values use `db:5432`.
+The internal `postgres` alias is retained only for compatibility with existing local
+`.env` files and should not be used in new configuration.
+
 The local virtual host is HTTP-only. Production must publish NGINX through the intended
 network interface, configure DNS for `azionelab.org`, terminate TLS, and prevent direct
 external access to application ports.

docs/operations.md

@@ -5,7 +5,7 @@
 ```bash
 docker compose up --build -d
 docker compose ps
-docker compose logs -f proxy backend frontend postgres
+docker compose logs -f proxy backend frontend db
 docker compose down
 ```
 
@@ -33,7 +33,7 @@ Back up the database and media at the same logical point in time:
 ```bash
 mkdir -p backups/media
 docker compose stop frontend backend
-docker compose exec -T postgres sh -c 'pg_dump -U "$POSTGRES_USER" "$POSTGRES_DB"' > backups/database.sql
+docker compose exec -T db sh -c 'pg_dump -U "$POSTGRES_USER" "$POSTGRES_DB"' > backups/database.sql
 docker compose cp backend:/app/media/. backups/media/
 docker compose start backend frontend
 ```

docs/runbook.md

@@ -4,7 +4,7 @@
 
 1. Check `docker compose ps` and the backend health status.
 2. Request `http://azionelab.org:8080/api/site/home/` through NGINX.
-3. Inspect `docker compose logs backend postgres`.
+3. Inspect `docker compose logs backend db`.
 4. Verify `PUBLIC_CMS_API_URL` resolves from the frontend container.
 5. Restart the frontend after recovery so its static page is rebuilt from CMS data.