Agile Web Development with Rails 7.2

Building a Docker Image

Before proceeding, let’s take one last look at the web service defined in the docker-compose.yml:

rails72/depot_td/docker-compose.yml

web:
  build: .
  volumes:
    - ./log:/rails/log
    - ./storage:/rails/storage
  ports:
    - "3000:3000"
  environment:
    - REDIS_URL=redis://redis-db:6379
    - DATABASE_URL=postgres://root:password@postgres-db/
  secrets:
    - source: master_key
      target: /rails/config/master.key
  depends_on:
    redis-db:
      condition: service_started
    postgres-db:
      condition: service_healthy

We’ve seen the volumes definition before; in this case it maps the log directory in the container to our local log directory, and the storage directory in the container to our local storage directory. ...