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Databases

Note

Currently out of the box PostgreSQL is configured only. For supporting e.g. MySQL you can adapt the config/base.yml and scripts/start accordingly.

Access to database (PostgreSQL) containers

An important part of development with databases is to access those from outside. This is possible by configuring exposed ports in the docker-compose.yml but leads to overlapping ports (e.g. 5432 for PostreSQL might be used as port for different projects).

One solution would be to have random ports assigned (with the downside to look those up every time), another could be to have a "global" database server handling all the databases of all the projects, a third to reserve / "namespace" different ports, like 5432, 5433 etc.. Neither of those is very elegant and might differ for different developers in the team.

The latest Traefik version (3, currently in beta) allows Host SNI routing that can be used especially for PostgreSQL database server (as those are not HTTP but only TCP).

The project setup looks like the following (for completeness the main service is included as well):

version: "3.7"
services:
  app:
    build:
      context: .
      dockerfile: Dockerfile
    depends_on:
      - db
    labels:
      - "traefik.enable=true"
      - "traefik.docker.network=my_network"
      - "traefik.http.services.my_project_app_service.loadbalancer.server.port=4000"
      - "traefik.http.routers.my_project_app_unsecure.rule=Host(`app.my-domain.localhost`)"
      - "traefik.http.routers.my_project_app_unsecure.entrypoints=web"
      - "traefik.http.routers.my_project_app_unsecure.middlewares=my_project_app_secure_middleware"
      - "traefik.http.middlewares.my_project_app_secure_middleware.redirectscheme.scheme=https"
      - "traefik.http.routers.my_project_app_secure.entrypoints=web-ssl"
      - "traefik.http.routers.my_project_app_secure.rule=Host(`app.my-domain.localhost`)"
      - "traefik.http.routers.my_project_app_secure.tls=true"

  db:
    image: postgres:14.5-alpine
    command: 'postgres -c "max_connections=200"'
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
    volumes:
      - type: volume
        source: postgres-data
        target: /var/lib/postgresql/data
        volume:
          nocopy: true
    labels:
      - "traefik.enable=true"
      - "traefik.docker.network=my_network"
      - "traefik.tcp.routers.my_project_db.rule=HostSNI(`db.my-domain.localhost`)"
      - "traefik.tcp.routers.my_project_db.entryPoints=postgres"
      - "traefik.tcp.routers.my_project_db.tls=true"
      - "traefik.tcp.services.my_project_db_service.loadbalancer.server.port=5432"
      
networks:
  default:
    name: my_network

The example above will expose app.my-domain.localhost as usual via port 443 but also expose db.my-domain.localhost on port 15432 for the database. With this you can establish a database connection from the tool of your choice.

Important

Note that for compatibility reasons the exposed port for PostgreSQL is 15432 instead of 5432. That is because one off tests without the proxy should be as easy as possible and some people might have a local PostgreSQL installation that might not be desired to be uninstalled.

Another advantage is that also here as for normal services you have TLS setup which might save you from some headaches when deploying to production (in case the database is TLS secured that is).