dvm

An on demand Docker virtual machine, thanks to Vagrant and boot2docker. Works great on Macs and other platforms that don't natively support the Docker daemon. Under the covers this is downloading and booting Mitchell Hashimoto's boot2docker Vagrant Box image.

The driving need for something like dvm was for running infrastructure testing, like Test Kitchen using the kitchen-docker driver. For the driver to work it needs access to all the dynamically assigned ports, not just the Docker daemon port. That's why dvm uses a private network segment and address (192.168.42.43 by default). Once Docker started supporting the DOCKER_HOST environment variable, the actual IP address was less important and consequently made the docker command on non-Linux distros feel almost native.

tl;dr for Mac Users

Are you already a Vagrant user using Virtualbox? Use Homebrew? Great!

# Install Docker Mac binary
brew install docker

# Install dvm
brew tap fnichol/dvm
brew install dvm

# Bring up your Vagrant/Docker VM
dvm up

# Set a DOCKER_HOST environment variable that points to your VM
eval $(dvm env)

# Run plain 'ol Docker commands right from your Mac
docker run ubuntu cat /etc/lsb-release

p.s. No Vagrant or VirtualBox installed? Check out the Requirements section below.

Requirements

• VirtualBox, version 4.3.4+, VMware Fusion/VMware Workstation, or Parallels Desktop
• Vagrant, version 1.4.0+
• (Optional) Docker, version 0.7.3+ or use the Docker Remote API

Use Homebrew Cask? For Vagrant and VirtualBox, too easy!

brew cask install vagrant    --appdir=/Applications
brew cask install virtualbox --appdir=/Applications

Install

Installation is supported for any Unixlike platform that Vagrant and VirtualBox/VMware support.

wget -O dvm-0.9.0.tar.gz https://github.com/fnichol/dvm/archive/v0.9.0.tar.gz
tar -xzvf dvm-0.9.0.tar.gz
cd dvm-0.9.0/
sudo make install

Installing with Homebrew (Mac)

There is a Homebrew tap with a formula which can be installed with:

brew tap fnichol/dvm
brew install dvm

Upgrade

You can follow the instructions for installing dvm.

Please note however that if the underlying boot2docker basebox is upgraded between versions, you will effectively get a new virtual machine when dvm restarts. A good idea before upgrading is to destroy your current dvm instance with dvm destroy.

Upgrading with Homebrew (Mac)

If using the dvm Homebrew tap, simply:

brew update
brew upgrade dvm

Also please read the above note about destroying in between upgrades.

Usage

Bring up help with:

$ dvm --help

Usage: dvm [-v|-h] command [<args>]

Options

  --version, -v - Print the version and exit
  --help, -h    - Display CLI help (this output)

Commands

  check           Ensure that required software is installed and present
  destroy         Stops and deletes all traces of the vagrant machine
  env             Outputs environment variables for Docker to connect remotely
  halt, stop      Stops the vagrant machine
  ip              Outputs the IP address of the vagrant machine
  reload          Restarts vagrant machine, loads new configuration
  resume          Resume the suspended vagrant machine
  ssh             Connects to the machine via SSH
  status          Outputs status of the vagrant machine
  suspend, pause  Suspends the machine
  up, start       Starts and provisions the vagrant environment
  vagrant         Issue subcommands directly to the vagrant CLI

Keep in mind that dvm thinly wraps Vagrant so don't hesitate to use raw Vagrant commands in your $HOME/.dvm directory. Or use the dvm vagrant subcommand from anywhere:

$ dvm vagrant --version
Vagrant 1.5.2

Bring up your VM with dvm up:

$ dvm up
Bringing machine 'dvm' up with 'virtualbox' provider...
...<snip>...
==> dvm: Configuring and enabling network interfaces...
==> dvm: Running provisioner: shell...
    dvm: Running: inline script

Or maybe you want to use the vmware_fusion Vagrant provider which isn't your default?

$ dvm up --provider=vmware_fusion

Need to free up some memory? Pause your VM with dvm suspend:

$ dvm suspend
==> dvm: Saving VM state and suspending execution...

When you come back to your awesome Docker project, resume your VM with dvm resume:

$ dvm resume
==> dvm: Resuming suspended VM...
==> dvm: Booting VM...
==> dvm: Waiting for machine to boot. This may take a few minutes...
    dvm: SSH address: 127.0.0.1:2222
    dvm: SSH username: docker
    dvm: SSH auth method: private key
    dvm: Warning: Connection refused. Retrying...
==> dvm: Machine booted and ready!

Your local docker binary needs to be told that it is targetting a remote system and to not try the local Unix socket, which is the default behavior. Version 0.7.3 of Docker introduced the DOCKER_HOST environment variable that will set the target Docker host. By default, dvm will run your VM on a private network at 192.168.42.43 with Docker listening on port 2375. The dvm env subcommand will print a suitable DOCKER_HOST line that can be used in your environment. If you want this loaded into your session, evaluate the resulting config with:

$ echo $DOCKER_HOST

$ eval `dvm env`

$ echo $DOCKER_HOST
tcp://192.168.42.43:2375

Check your VM status with dvm status:

$ dvm status
Current machine states:

dvm                       running (virtualbox)

The VM is running. To stop this VM, you can run `vagrant halt` to
shut it down forcefully, or you can run `vagrant suspend` to simply
suspend the virtual machine. In either case, to restart it again,
simply run `vagrant up`.

Log into your VM (via SSH) with dvm ssh:

$ dvm ssh
                        ##        .
                  ## ## ##       ==
               ## ## ## ##      ===
           /""""""""""""""""\___/ ===
      ~~~ {~~ ~~~~ ~~~ ~~~~ ~~ ~ /  ===- ~~~
           \______ o          __/
             \    \        __/
              \____\______/
 _                 _   ____     _            _
| |__   ___   ___ | |_|___ \ __| | ___   ___| | _____ _ __
| '_ \ / _ \ / _ \| __| __) / _` |/ _ \ / __| |/ / _ \ '__|
| |_) | (_) | (_) | |_ / __/ (_| | (_) | (__|   <  __/ |
|_.__/ \___/ \___/ \__|_____\__,_|\___/ \___|_|\_\___|_|
boot2docker: 1.0.0
             master : 16013ee - Mon Jun  9 16:33:25 UTC 2014
docker@boot2docker:~$

Embed in a Project

As the core of dvm is a Vagrantfile (surprise!), you can simply download the dvm Vagrantfile into your project using the http://git.io/dvm-vagrantfile shortlink:

wget -O Vagrantfile http://git.io/dvm-vagrantfile

Configuration

If you wish to change the Docker TCP port or memory settings of the virtual machine, edit $HOME/.dvm/dvm.conf for the configuration to be used. By default the following configuration is used:

• DOCKER_IP: 192.168.42.43
• DOCKER_PORT: 2375
• DOCKER_MEMORY: 512 (in MB)
• DOCKER_CPUS: 1
• DOCKER_ARGS: -H unix:// -H tcp://

If you wish to change the network range Docker uses for the docker0 bridge, set DOCKER0_CIDR to the range required.

See dvm.conf for more details.

Development

• Source hosted at GitHub
• Report issues/questions/feature requests on GitHub Issues

Pull requests are very welcome! Make sure your patches are well tested. Ideally create a topic branch for every separate change you make. For example:

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

Authors

Created and maintained by Fletcher Nichol (fnichol@nichol.ca)

Credits

• Steeve Morin (steeve) for boot2docker
• Mitchell Hashimoto (mitchellh) for Vagrant and boot2docker Vagrant Box
• Postmodern (postmodern) for awesome examples of killer project skeletons in chruby and ruby-install

License

Apache 2.0 (see LICENSE.txt)