Puppet module for installing Docker from the official repository.

This module is also available on the Puppet Forge

Usage

The module includes a single class:

include 'docker'

By default this sets up the docker hosted Apt repository and installs the lxc-docker package and the required Kernel.

If you don't want this module to mess about with your Kernel then you can disable this feature like so:

class { 'docker':
  manage_kernel => false,
}

By default the docker daemon will bind to a unix socket at /var/run/docker.sock. This can be changed, as well as binding to a tcp socket if required.

class { 'docker':
  tcp_bind    => 'tcp://127.0.0.1:4243',
  socket_bind => 'unix:///var/run/docker.sock',
}

Unless specified this installs the latest version of docker from the lxc-docker package. However if you want to specify a specific version you can do so:

class { 'docker':
  version => '0.5.5',
}

Images

The next step is probably to install a docker image, for this we have a defined type which can be used like so:

docker::image { 'base': }

This is equivalent to running docker pull base.
This is downloading a large binary so on first run can take a while.
For that reason this define turns off the default 5 minute timeout for exec.
Takes an optional parameter for installing image tags that is the equivalent to running docker pull -t="precise" ubuntu:

docker::image { 'ubuntu':
  image_tag => 'precise'
}

Note: images will only install if an image of that name does not already exist.

You can also remove images you no longer need with:

docker::image { 'base':
  ensure => 'absent'
}

docker::image { 'ubuntu':
  ensure    => 'absent',
  image_tag => 'precise'
}

Containers

Now you have an image you can run commands within a container managed by docker.

docker::run { 'helloworld':
  image   => 'base',
  command => '/bin/sh -c "while true; do echo hello world; sleep 1; done"',
}

This is equivalent to running the following under upstart:

docker run -d base /bin/sh -c "while true; do echo hello world; sleep 1; done"

Run also contains a number of optional parameters:

docker::run { 'helloworld':
  image        => 'base',
  command      => '/bin/sh -c "while true; do echo hello world; sleep 1; done"',
  ports        => ['4444', '4555'],
  links        => ['mysql:db'],
  use_name     => true,
  volumes      => ['/var/lib/couchdb', '/var/log'],
  volumes_from => '6446ea52fbc9',
  memory_limit => 10485760, # bytes 
  username     => 'example',
  hostname     => 'example.com',
  env          => ['FOO=BAR', 'FOO2=BAR2'],
  dns          => ['8.8.8.8', '8.8.4.4'],
}

Ports, env, dns and volumes can be set with either a single string or as above with an array of values.

To use an image tag just append the tag name to the image name separated by a semicolon:

docker::run { 'helloworld':
  image   => 'ubuntu:precise',
  command => '/bin/sh -c "while true; do echo hello world; sleep 1; done"',
}