= Docker Compose =

'''Docker Compose''' is a method for creating containers through configuration files.

<<TableOfContents>>

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== Installation ==

Most [[Linux]] distributions offer a `docker-compose` package.

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== Compose Files ==



=== Volumes ===

Docker compose supports two methods for creating [[Docker/Volumes|volumes]] and [[Docker/BindMounts|bind mounts]]. The ''long'' syntax, which is recommended, is:

{{{
container_name: my-container
version: 0.1
services:
  web:
    image: my-image
    volumes:
      - type: bind
        source: relative/source/path
        target: /absolute/target/path
        read only: true
}}}

The ''short'' syntax is:

{{{
container_name: my-container
version: 0.1
services:
  web:
    image: my-image
    volumes:
      - relative/source/path:/absolute/target/path:ro
}}}



=== Publishing ===

Docker compose supports two methods to expose a container to the network. The ''short'' syntax is:

{{{
container_name: my-container
version: 0.1
services:
  web:
    image: my-image
    ports:
      - 127.0.0.1:80:8080/tcp
}}}

If the host [[Protocols/IP|IP]] is not set, the service will listen on all interfaces. If the protocol is not specified, both [[Protocols/TCP|TCP]] and [[Protocols/UDP|UDP]] connections are accepted. So it can be expressed simply as:

{{{
container_name: my-container
version: 0.1
services:
  web:
    image: my-image
    ports:
      - 80:8080
}}}

The ''long'' syntax is:

{{{
container_name: my-container
version: 0.1
services:
  web:
    image: my-image
    ports:
      - target: 80
        host_ip: 127.0.0.1
        published: "8080"
        protocol: tcp
        mode: host
}}}

In this syntax, `published` is a string because it can be expressed as a range (like `"8000-9000"`).



=== Environment Variables ===

To pass in an environment variable from the local environment to a Docker container, use:

{{{
container_name: my-container
version: 0.1
services:
  web:
    image: my-image
    environment:
      - VARIABLE1
      - VARIABLE2
}}}

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== See also ==

[[https://docs.docker.com/compose/compose-file/|Docker compose reference documentation]]



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