Docker compose

What is?

The docker-compose.yml is the file in charge to save us time in configuring each container and each time we have to set up each one.

What is .yml?

It is the language that configures the docker-compose files

Building our docker compose file

version: "3.9"

services:
  # First here we will define the name of our containers
  # And it is very important that here we has a line break
  myapp:
    # Here we specify the route of our Dockerfile
    build: .
    # Here, between "", we set the port mapping
    ports:
      - "3000:3000"
    # Here the connections with other containers based on their NAMES without ""
    links:
      - mongon

  # Here we set the db image configuration
  mongon:
    # From waht image will be created
    image: mongo
    # Ports mapping for db
    ports:
      - "27017:27017"
    # Environment variables (.env)
    environment:
      - MONGO_INITDB_ROOT_USERNAME=alan
      - MONGO_INITDB_ROOT_PASSWORD=password

Finally, to setup automatically all containers, we just have to execute docker compose up in the root path of our project. This command will create some images and containers that can be removed gracefully using the opposite command: docker compose down

Another good feature of using docker compose files, is that all containers declared there will be set in a network automatically