Master Docker Compose: Essential Commands and YAML Configuration Explained

Docker Compose Common Commands

Docker Compose manages multi‑container applications defined in a docker-compose.yml file. The most frequently used commands are:

ps – List containers in the current project. docker-compose ps build – Build or rebuild images for services. docker-compose build up – Create and start containers. Add -d to run in detached mode. docker-compose up -d down – Stop and remove containers, networks, and volumes created by up. docker-compose down logs – View combined logs of all services (or a specific one). docker-compose logs -f redis start – Start existing stopped containers. docker-compose start mysql stop – Stop running containers. docker-compose stop mysql rm – Remove stopped containers (add -f to force). docker-compose rm -f redis run – Run a one‑off command in a new container of a service. docker-compose run web bash exec – Execute a command in an already‑running container.

docker-compose exec web python manage.py migrate

port – Show the host port mapped to a container port. docker-compose port mysql 3306 pull – Pull service images from a registry. docker-compose pull redis:latest When the compose file has a non‑default name, specify it with -f, e.g. docker-compose -f my-compose.yml up.

docker-compose.yml File Structure

A Compose file is indentation‑sensitive YAML. The top‑level sections are:

version – Compose file format version (e.g. "3" for Docker 1.13+).

services – Definition of each container (service) and its configuration.

networks – (Optional) Custom network definitions.

volumes – (Optional) Named volume definitions.

Key Service Fields

image – Image name (registry/repo:tag) or ID. image: redis:latest container_name – Custom name for the container. container_name: im-redis-compose build – Build instructions when an image must be built from a Dockerfile.

build:
  context: ./my_dir
  dockerfile: Dockerfile-alternate
  args:
    buildno: 1

environment – Environment variables passed to the container.

environment:
  - DATA_SOURCE_NAME="user:password@(hostname:3306)/"

ports – Host‑to‑container port mappings. Simple "HOST:CONTAINER" format or long format (v3.2+).

# Simple mapping
- "3000:3000"
# Long format example
- target: 80
  published: 8080
  protocol: tcp
  mode: host

volumes – Volume mounts. Supports anonymous, host‑path, and named volumes with optional ro / rw flags.

volumes:
  - /var/lib/mysql                     # anonymous
  - /opt/data:/var/lib/mysql           # host‑path bind
  - ./cache:/tmp/cache                 # relative bind
  - datavolume:/var/lib/mysql           # named volume

restart – Restart policy (e.g. no, always, on-failure, unless-stopped).

network_mode – Set the network mode ( bridge, host, none, service:[service], container:[id]).

depends_on – Declare service dependencies to control start order.

links – Legacy way to link containers; also influences start order.

pid – Share the host PID namespace ( host).

Example docker-compose.yml

version: "3"
services:
  redis:
    image: redis:latest
    ports:
      - "6379:6379"
    container_name: im-redis-compose
    restart: always
    command: redis-server --appendonly yes

  rabbitmq:
    image: rabbitmq:management
    ports:
      - "5672:5672"
      - "15672:15672"
    container_name: im-rabbitmq-compose
    environment:
      RABBITMQ_DEFAULT_USER: guest
      RABBITMQ_DEFAULT_PASS: guest
      RABBITMQ_DEFAULT_VHOST: my_vhost

  backend:
    build: .
    links:
      - redis
      - rabbitmq
    container_name: im-server-compose
    restart: on-failure
    depends_on:
      - rabbitmq
      - redis
    ports:
      - "3000:3000"
    command: sh -c './wait-for.sh rabbitmq:15672'

This example defines a three‑service stack (Redis, RabbitMQ, and a custom backend) with explicit container names, restart policies, port mappings, environment variables, and inter‑service dependencies.

Version Compatibility

Compose file formats have three major versions: 1, 2.x, and 3.x. The current mainstream is 3.x, which requires Docker Engine 1.13.0 or newer.

Specify the version at the top of the file, e.g. version: "3", to enable the corresponding syntax and features.

Additional Service Options

expose – Expose ports to linked services without publishing them to the host.

expose:
  - "3000"
  - "8000"

networks – Attach a service to one or more custom networks and optionally define aliases.

networks:
  some-network:
    aliases:
      - alias1
  other-network:
    aliases:
      - alias2