docker-compose.md

title	category	prism_languages	weight	updated
docker-compose	Devops	yaml	-1	2024-04-03

Basic example

# docker-compose.yml
version: '2'

services:
  web:
    build:
    # build from Dockerfile
      context: ./Path
      dockerfile: Dockerfile
    ports:
     - "5000:5000"
    volumes:
     - .:/code
  redis:
    image: redis

Version 1 to 2

Docker compose is now integrated into the official Docker installation. The functionality only improved over that change, and the simple syntax change is : V1 : docker-compose ARG to V2 docker compose ARG More on that here : Docker Compose Migrate to V2

Commands

docker compose version 
docker compose config    

docker compose start
docker compose stop
docker compose restart
docker compose run    

docker compose create  
docker compose attach      
docker compose pause
docker compose unpause

docker compose wait   
docker compose up
docker compose down

docker compose ps
docker compose top 
docker compose events   
docker compose logs

docker compose images
docker compose build      
docker compose push  
docker compose cp       
docker compose exec 

Reference

{: .-three-column}

Building

web:
  # build from Dockerfile
  build: .
  args:     # Add build arguments
    APP_HOME: app

  # build from custom Dockerfile
  build:
    context: ./dir
    dockerfile: Dockerfile.dev

  # build from image
  image: ubuntu
  image: ubuntu:14.04
  image: tutum/influxdb
  image: example-registry:4000/postgresql
  image: a4bc65fd

Ports

  ports:
    - "3000"
    - "8000:80"  # host:container

  # expose ports to linked services (not to host)
  expose: ["3000"]

Commands

  # command to execute
  command: bundle exec thin -p 3000
  command: [bundle, exec, thin, -p, 3000]

  # override the entrypoint
  entrypoint: /app/start.sh
  entrypoint: [php, -d, vendor/bin/phpunit]

Environment variables

  # environment vars
  environment:
    RACK_ENV: development
  environment:
    - RACK_ENV=development

  # environment vars from file
  env_file: .env
  env_file: [.env, .development.env]

Dependencies

  # makes the `db` service available as the hostname `database`
  # (implies depends_on)
  links:
    - db:database
    - redis

  # make sure `db` is alive before starting
  depends_on:
    - db

  # make sure `db` is healty before starting
  # and db-init completed without failure
  depends_on:
    db:
      condition: service_healthy
    db-init:
      condition: service_completed_successfully

Other options

  # make this service extend another
  extends:
    file: common.yml  # optional
    service: webapp

  volumes:
    - /var/lib/mysql
    - ./_data:/var/lib/mysql

  # automatically restart container
  restart: unless-stopped
  # always, on-failure, no (default)

Advanced features

{: .-three-column}

Labels

services:
  web:
    labels:
      com.example.description: "Accounting web app"

DNS servers

services:
  web:
    dns: 8.8.8.8
    dns:
      - 8.8.8.8
      - 8.8.4.4

Devices

services:
  web:
    devices:
    - "/dev/ttyUSB0:/dev/ttyUSB0"

External links

services:
  web:
    external_links:
      - redis_1
      - project_db_1:mysql

Healthcheck

    # declare service healthy when `test` command succeed
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost"]
      interval: 1m30s
      timeout: 10s
      retries: 3
      start_period: 40s

Hosts

services:
  web:
    extra_hosts:
      - "somehost:192.168.1.100"

Network

# creates a custom network called `frontend`
networks:
  frontend:

External network

# join a pre-existing network
networks:
  default:
    external:
      name: frontend

Volume

# mount host paths or named volumes, specified as sub-options to a service
  db:
    image: postgres:latest
    volumes:
      - "/var/run/postgres/postgres.sock:/var/run/postgres/postgres.sock"
      - "dbdata:/var/lib/postgresql/data"

volumes:
  dbdata:

User

# specifying user
user: root

# specifying both user and group with ids
user: 0:0

Secrets

# in the container, /run/secrets/my_secret is set to the contents of the file ./my_secret.txt
services:
  myapp:
    image: myapp:latest
    secrets:
      - my_secret
secrets:
  my_secret:
    file: ./my_secret.txt