Sunday September 19 2010
The SteamCannon project uses Deltacloud to abstract away the details of specific cloud providers when launching instances. For local development, it's nice to be able to launch a cluster of virtual machines in VirtualBox instead of actually starting and stopping instances on a public cloud like Amazon EC2.
Michal Fojtik created a deltacloud-virtualbox-driver many months ago to add VirtualBox support to Deltacloud. However, Deltacloud has evolved quite a bit since it was initially released and that driver no longer works with the current implementation.
I've taken Michal's great start and updated it to work with the latest Deltacloud release, giving it a few other changes in the process.
Switched to the excellent virtualbox gem which uses the VirtualBox COM API instead of shelling out to the VBoxManage process. The COM API is substantially faster and should allow this driver to work on Windows instead of just Linux/Mac (but it hasn't been tested on Windows).
Networking settings of the launched instance are now copied from the parent image instead of being hardcoded to a specific value.
The driver now works under JRuby. There are still some optimizations to be made in the code based on which environment it's running in, but it will at least run in JRuby and MRI.
Installing the VirtualBox Driver
The driver is very new and still needs to mature a bit before I submit it to the upstream Deltacloud project. Until then, if you're comfortable living on the edge, read below for installation instructions.
Install VirtualBox 3.2.x (might work with 3.1.x but has not been tested) - http://www.virtualbox.org/wiki/Downloads
Install bbrowning-virtualbox gem (temporary fork of upstream implementing some missing features)
$ gem install bbrowning-virtualbox --pre
Install bbrowning-deltacloud-core gem
$ gem install bbrowning-deltacloud-core
Launch deltacloud-core with the VirtualBox driver
$ deltacloudd -i virtualbox
If all goes well, you should be able to go to http://localhost:3001 in your browser and see the Deltacloud web interface. Clicking the Images link should display all virtual machines you have setup inside VirtualBox - if you don't see any, try creating a new virtual machine in VirtualBox and then come back to play around.
The instances launched from an image clone the hard drive of the image but any changes made in the instance are not reflected in the parent image. If you don't have a lot of free hard drive space, make sure to go to the Instances page and destroy stopped instances that you no longer need.