Introduction to Crowbar (and how you can do it, too!)

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Keith Hudgins / August 25th, 2011

Dell’s Crowbar is a provisioning tool that combines the best of Chef, OpenStack, and Convention over Configuration to enable you to easily provision and configure complex infrastructure components that would take days, if not weeks to get up and running without such a tool.

What is Crowbar?

Crowbar was oribinally written as a simplified installer for OpenStack’s compute cloud control system Nova. Because you can’t run Nova without having at least three separate components (one of which requiring its own physical server), creating an automated install system requires more than just running a script on a server or popping in a disk.

Crowbar consists of three major parts:

 

1. Sledgehammer: A lightweight CentOS-based boot image that does hardware discovery and phones home to Crowbar for later assignment. It can also munge the BIOS settings on Dell hardware.
2. OpenStack Manager: This is the Ruby-on-Rails based web ui to Crowbar. (Fun fact: it uses Chef as its datastore… there’s some pretty sweet Rails model hackery inside!)
3. Barclamps: The meat and potatoes of Crowbar – these are the install modules that set up and configure your infrastructure (across multiple physical servers, even)

 

Dell and other contributors have been working on extending Crowbar outside of just OpenStack as a generalized infrastructure provisioning tool. This article is the first in a 3-part series describing the development and build-up to a Barclamp (A crowbar install snippet) that gets CloudFoundry running for you.

So, that’s neat and all, but what if you want to hack on this stuff and don’t have a half-rack worth of servers lying around? This is DevOps, man, you virtualize it! (Automation will come later. I promise!)

Virtualizing Crowbar

The basics of this are shown on Rob Hirschfield’s blog and a little more on project wiki. Dell, being Dell, is pretty much a Windows shop. We don’t hold that against them, but the cool kids chew their DevOps chops on Mactops and Linux boxen. Since VMWare Fusion isn’t that far from VMWare Workstation, it only took a half day of reading docs and forum posts to come up with a reliable way to do it on a Mac

Those Instructions Are Here.

Bonus homework: Get that running and read down to the bottom of the DTO Knowledge Base article I just linked, and you’ll get a sneak preview of where we’re going with this article series.

Now, go on to part 2!