vagrant/plugins/providers/docker

docker-provider

A Docker provider for Vagrant 1.4+.

Warning

This is experimental, expect things to break.

Requirements

• Vagrant 1.4+
• Docker 0.7.0+

Features

• Support for Vagrant's up, destroy, halt, reload and ssh commands
• Port forwarding
• Synced / shared folders support
• Set container hostnames from Vagrantfiles
• Provision Docker containers with any built-in Vagrant provisioner (as long as the container has a SSH server running)

You can see the plugin in action by watching the following asciicasts I published prior to releasing 0.0.1:

• http://asciinema.org/a/6162
• http://asciinema.org/a/6177

Getting started

If you are on a Mac / Windows machine, please fire up a x64 Linux VM with Docker + Vagrant 1.4+ installed or use this Vagrantfile and follow the instructions from within the VM.

It is likely that the plugin works with boot2docker but I personally haven't tried that yet. If you are able to give it a go please let me know.

Initial setup

If you are trying things out from a Vagrant VM using the Vagrantfile gisted above, you can skip to the next section

The plugin requires Docker's executable to be available on current user's PATH and that the current user has been added to the docker group since we are not using sudo when interacting with Docker's CLI. For more information on setting this up please check this page.

vagrant up

On its current state, the plugin is not "user friendly" and won't provide any kind of feedback about the process of downloading Docker images, so before you add a docker-provider base box it is recommended that you docker pull the associated base box images prior to spinning up docker-provider containers (otherwise you'll be staring at a blinking cursor without any progress information for a while).

Assuming you have Vagrant 1.4+ and Docker 0.7.0+ installed just sing that same old song:

vagrant plugin install docker-provider
docker pull fgrehm/vagrant-ubuntu:precise
vagrant box add precise64 http://bit.ly/vagrant-docker-precise
vagrant init precise64
vagrant up --provider=docker

Under the hood, that base box will configure docker-provider to use the fgrehm/vagrant-ubuntu:precise image that approximates a standard Vagrant box (vagrant user, default SSH key, etc.) and you should be good to go.

Using custom images

If you want to use a custom Docker image without creating a Vagrant base box, you can use a "dummy" box and configure things from your Vagrantfile like in vagrant-digitalocean or vagrant-aws:

Vagrant.configure("2") do |config|
  config.vm.box = "dummy"
  config.vm.box_url = "http://bit.ly/vagrant-docker-dummy"
  config.vm.provider :docker do |docker|
    docker.image = "your/image:tag"
  end
end

Configuration

This provider exposes a few provider-specific configuration options that are passed on to docker run under the hood when the container is being created:

• image - Docker image to run (required)
• privileged - Give extended privileges to the container (defaults to false)
• cmd - An array of strings that makes up for the command to run the container (defaults to what has been set on your Dockerfile as CMD or ENTRYPOINT)
• ports - An array of strings that makes up for the mapped network ports
• volumes - An array of strings that makes up for the data volumes used by the container

These can be set like typical provider-specific configuration:

Vagrant.configure("2") do |config|
  # ... other stuff

  config.vm.provider :docker do |docker|
    docker.image      = 'fgrehm/vagrant-ubuntu-dind:precise'
    docker.privileged = true
    docker.cmd        = ['/dind', '/sbin/init']

    docker.ports   << '1234:22'
    docker.volumes << '/var/lib/docker'
  end
end

Networks

Networking features in the form of config.vm.network are not supported with docker-provider apart from forwarded ports. If any of :private_network or :public_network are specified, Vagrant won't emit a warning.

The same applies to changes on forwarded ports after the container has been created, Vagrant won't emit a warning to let you know that the ports specified on your Vagrantfile differs from what has been passed on to docker run when creating the container.

At some point the plugin will emit warnings on the scenarios described above, but not on its current state. Pull Requests are encouraged ;)

Synced Folders

There is support for synced folders on the form of Docker volumes but as with forwarded ports, you won't be able to change them after the container has been created. NFS synced folders are also supported (as long as you set the privileged config to true so that docker-provider can mount it on the guest container) and are capable of being reconfigured between vagrant reloads (different from Docker volumes).

This is good enough for all built-in Vagrant provisioners (shell, chef, and puppet) to work!

At some point the plugin will emit warnings when the configured Vagrantfile synced folders / volumes differs from the ones used upon the container creation, but not on its current state. Pull Requests are encouraged ;)

Box format

Every provider in Vagrant must introduce a custom box format. This provider introduces docker boxes and you can view some examples in the boxes directory. That directory also contains instructions on how to build them.

The box format is basically just the required metadata.json file along with a Vagrantfile that does default settings for the provider-specific configuration for this provider.

Available base boxes

LINK	DESCRIPTION
http://bit.ly/vagrant-docker-precise	Ubuntu 12.04 Precise x86_64 with Puppet and Chef preinstalled and configured to run /sbin/init
http://bit.ly/vagrant-docker-precise-dind	Ubuntu 12.04 Precise x86_64 based on the box above and ready to run DinD

Limitations

As explained on the networks and synced folder sections above, there are some "gotchas" when using the plugin that you need to have in mind before you start to pull your hair out.

For instance, forwarded ports, synced folders and containers' hostnames will not be reconfigured on vagrant reloads if they have changed and the plugin will not give you any kind of warning or message. As an example, if you change your Puppet manifests / Chef cookbooks paths (which are shared / synced folders under the hood), you'll need to start from scratch (unless you make them NFS shared folders). This is due to a limitation in Docker itself as we can't change those parameters after the container has been created.

Forwarded ports automatic collision handling is not supported as well.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request