vagrant-lxc

Linux Containers support for Vagrant 1.1+

Dependencies

• Vagrant 1.1+ (1.1.3+ recommended)
• lxc 0.7.5+ (0.8.0-rc1+ recommended)
• redir (if you are planning to use port forwarding)
• arch command (uname -m) on PATH
• A Kernel higher than 3.5.0-17.28

On a clean Ubuntu 12.10 machine it means something like:

sudo apt-get update && sudo apt-get dist-upgrade
sudo apt-get install lxc redir
# Downloads and install Vagrant 1.1.5
wget "http://files.vagrantup.com/packages/64e360814c3ad960d810456add977fd4c7d47ce6/vagrant_`uname -m`.deb" -O /tmp/vagrant.deb
sudo dpkg -i /tmp/vagrant.deb

What is currently supported? (v0.3.0)

Pretty much everything you need from Vagrant:

• Vagrant's up, halt, reload, destroy, ssh and package commands (box packaging is kind of experimental)
• Shared folders
• Provisioning
• Setting container's host name
• Port forwarding

Please refer to the closed issues and the changelog for most up to date information.

Current limitations

• Does not detect forwarded ports collision, right now you are responsible for taking care of that
• A hell lot of sudos (this will probably be like this until user namespaces are supported)
• Only a single ubuntu box supported
• "works on my machine" (TM)
• Does not tell you if dependencies are not met (will probably just throw up some random error)
• • bunch of other core features and some known bugs

Installation

vagrant plugin install vagrant-lxc

Usage

After installing, add the quantal64 base box using any name you want:

vagrant box add lxc-quantal64 http://dl.dropbox.com/u/13510779/lxc-quantal64-2013-04-10.box

Make a Vagrantfile that looks like the following, filling in your information where necessary:

Vagrant.configure("2") do |config|
  config.vm.box = "lxc-quantal64"

  # You can omit this block if you don't need to override any container setting
  config.vm.provider :lxc do |lxc|
    # OPTIONAL: Same effect as as 'customize ["modifyvm", :id, "--memory", "1024"]' for VirtualBox
    lxc.customize 'cgroup.memory.limit_in_bytes', '1024M'
    # OPTIONAL: Limits swap size
    lxc.customize 'cgroup.memory.memsw.limit_in_bytes', '512M'
  end
end

And finally run vagrant up --provider=lxc.

If you are on a mac or window host and still want to try this plugin out, you can use the same Vagrant VirtualBox machine I use for development.

Storing container's rootfs on a separate partition

Before the 0.3.0 version of this plugin, there used to be a support for specifying the container's rootfs path from the Vagrantfile, on 0.3.0 this was removed as you can achieve the same effect by symlinking or mounting /var/lib/lxc on a separate partition.

NFS shared folders

NFS shared folders are not supported and will behave as a "normal" shared folder so we can share the same Vagrantfile with VBox environments.

Development

If want to develop from your physical machine, just sing that same old song:

git clone git://github.com/fgrehm/vagrant-lxc.git
cd vagrant-lxc
bundle install
bundle exec rake # to run all specs

To build the provided quantal64 box:

bundle exec rake boxes:quantal64:build
vagrant box add quantal64 boxes/output/lxc-quantal64.box

Using vagrant-lxc to develop itself

Yes! The gem has been [bootstrapped](http://en.wikipedia.org/wiki/Bootstrapping_(compilers) and since you can boot a container from within another, after cloning the project you can run the commands below from the host machine to get a container ready for development:

# Required in order to allow nested containers to be started
sudo apt-get install apparmor-utils
sudo aa-complain /usr/bin/lxc-start
bundle install
cd development
bundle exec vagrant up lxc --provider=lxc
bundle exec vagrant ssh lxc

That should result in a container ready to be bundle exec vagrant sshed. Once you've SSH into the guest container, you'll be already on the project's root. Keep in mind that you'll probably need to run sudo aa-complain /usr/bin/lxc-start on the host whenever you want to hack on it, otherwise you won't be able to start nested containers there to try things out.

Using VirtualBox for development

cd development
bundle exec vagrant up vbox
# A reload is needed to ensure the updated kernel gets loaded
bundle exec vagrant reload vbox
bundle exec vagrant ssh vbox

Protips

If you want to find out more about what's going on under the hood on vagrant, prepend VAGRANT_LOG=debug to your vagrant commands. For lxc-starts debugging set LXC_START_LOG_FILE:

LXC_START_LOG_FILE=/tmp/lxc-start.log VAGRANT_LOG=debug vagrant up

This will output A LOT of information on your terminal and some useful information about lxc-start to /tmp/lxc-start.log.

Help! I'm unable to restart containers!

It happened to me quite a few times in the past and it seems that it is related to a bug on linux kernel, so make sure you are using a bug-free kernel (>= 3.5.0-17.28). More information can be found on:

• https://bugzilla.kernel.org/show_bug.cgi?id=47181
• https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1021471
• https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1065434

Sometimes the dev boxes I'm using are not able to lxc-start containers anymore. Most of the times it was an issue with the arguments I provided to it for customization (or a buggy kernel). If you run into that, rollback your changes and try to vagrant reload the dev box. If it still doesn't work, please file a bug at the issue tracker.

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