docker-compose.md

title	category	layout	prism_languages	weight	updated
docker-compose	Devops	2017/sheet	yaml	-1	2020-01-01

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

Commands

docker-compose start
docker-compose stop

docker-compose pause
docker-compose unpause

docker-compose ps
docker-compose up
docker-compose down

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