How to connect GitHub repository to a Dockerized database?

Hello, @jackpotjunkremovallasvegas

You can put your app and your DB in the same docker-compose.yml, let Docker handle networking, and connect using the service name as the host, with credentials coming from environment variables (or a .env file), not hard-coded values or IPs.

From there, most of the “connection refused / timeout / env not read” problems disappear.

Imagine your app lives in this repo and has a Dockerfile at the root. The app expects DB settings from environment variables like DB_HOST, DB_USER, etc.

Here’s an example docker-compose.yml:

version: "3.9"

services:
  db:
    image: postgres:16
    container_name: myapp-db
    environment:
      POSTGRES_USER: myuser
      POSTGRES_PASSWORD: mypassword
      POSTGRES_DB: myapp
    volumes:
      - db_data:/var/lib/postgresql/data
    ports:
      - "5432:5432"
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U myuser -d myapp"]
      interval: 5s
      timeout: 5s
      retries: 10

  app:
    build: .
    container_name: myapp-app
    depends_on:
      db:
        condition: service_healthy
    environment:
      DB_HOST: db         # IMPORTANT: use service name, not localhost or IP
      DB_PORT: 5432
      DB_USER: myuser
      DB_PASSWORD: mypassword
      DB_NAME: myapp
      # any other env your app needs...
    ports:
      - "8000:8000"
    # command: ["your", "start", "command"]  # if not defined in Dockerfile

volumes:
  db_data:

Regards

Hi,

The easiest and most reliable setup is to run your app and your database inside the same docker-compose network. Instead of connecting via IPs, you simply use the service name as the hostname and Docker handles the DNS resolution for you.

Here’s a small example:

services:
  db:
    image: postgres:16
    environment:
      POSTGRES_PASSWORD: example
    ports:
      - 5432:5432

  app:
    build: .
    env_file: .env
    depends_on:
      - db
    environment:
      DATABASE_URL: postgres://postgres:example@db:5432/mydb

With this setup, your app talks to the database at ‘db:5432’ rather than an IP. Credentials should go into environment variables or an env file so you don’t have to hardcode anything. Compose automatically creates a shared network, so the containers can communicate cleanly without extra config. If you’re pulling the code from GitHub, let GitHub Actions build and push your application image, then run it with compose on your server.

https://devops-daily.com/posts/rebuild-docker-container-compose

If you want to avoid managing the database yourself, you can also look into DigitalOcean Managed Databases which make this part much easier:

https://docs.digitalocean.com/products/databases/