Compose

Running multiple containers

Why
Configure relationships between containers
Save docker container run settings in easy-to-read file
create one-liner development environment startups
Comprised of 2 separate but related things:
YAML formatted file that describes solution options for:
containers
volumes
networks
A CLI tool docker-compose used for local dev/test automation
Installed automatically on Mac and Windows with Docker Desktop, for Linux must be downloaded separately.
Links
​Compose on GitHub​
​Compose documentation​
Example
version: '3'
​
services:
  drupal:
    image: drupal:8-apache
    ports:
    - '8080:80'
    volumes:
    - drupal-modules:/var/www/html/modules
    - drupal-profiles:/var/www/html/profiles
    - drupal-sites:/var/www/html/sites
    - drupal-themes:/var/www/html/themes
    restart: always
  postgres:
    image: postgres:10
    environment:
      POSTGRES_PASSWORD: [email protected]
    restart: always
​
volumes:
  drupal-modules:
  drupal-profiles:
  drupal-sites:
  drupal-themes:
​
Commands
To start
docker-compose up [--build] [...options]
To tear down
docker-compose down [-v] [...other options]
Using compose with build
compose can also build your images
will build them with docker-compose up if not found in cache
also rebuild with docker-compose build
great for complex builds that have lots of vars or build args
Example
version: '3'
​
services:
  proxy:
    build:
      context: .
      dockerfile: nginx.Dockerfile
    image: nginx-custom
    ports:
    - '80:80'
  web:
    image: httpd
    volumes:
    - ./html:/usr/local/apache2/htdocs/
Restart policies
"no" - never attempt to restart this container if it stops or crashes (must be in "")
always - if this container stops, for any reason, always attempt to restart it
on-failure - only restart if the container stops with an error code
unless-stopped - always restart unless we forcibly stop it
​

System

Swarm

Last modified 3yr ago