Create a Postgres container with a init script. You can create your initial database tables with a init.sql file in ./data/postgres/init.sql in your project.

docker-compose.yml

version: "3"
services:
  database:
    image: postgres:9.6
    container_name: "postgres-db"
    environment:
      - POSTGRES_DB=db_name
      - POSTGRES_USER=db_user
      - POSTGRES_PASSWORD=db_password
      - POSTGRES_HOST_AUTH_METHOD=trust
      - TZ=GMT
    volumes:
      - ./data/postgres/init.sql:/docker-entrypoint-initdb.d/init.sql
    ports:
      - 5432:5432