Philly ETE, Day 2: Session 5

Chef: Saving Time (and Money) with Automated Provisioning

-- Trotter Cashion

Trotter starts by talking about his own user experience with automating deployment. His company looked at Chef, decided it would be too complicated, and decided to create the automation themselves using Bash. It was a big win at first, but over time it became way too difficult to maintain, adding new machines was time consuming, and there were still too many manual tasks involved.

So eventually they moved to Chef.

Chef is...

written by Opscode

written in Ruby

in some sort of controversy with Puppet

driven by a Ruby DSL

Chef has a concept of 'cookbooks.' It's a set of instructions to install any piece of software that are published by Opscode. It can also keep machine and code in lock-step. So you can deploy your software for any environment ("QA", "performance," "development") and configuration may well vary among them. Chef helps you keep all of the necessary elements by organizing all of the environments with a particular set of cookbooks.

One main difference between Capistrano and Chef is that Chef eschews the concept of SSH. Chef assumes that it is already on the box on which it is installing software. It also assumes that it has root access.

According to Trotter, Chef provisioning takes between 15 and 30 minutes and deploys take under 2 minutes.

Using Chef with Spatula:

git clone http://github.com/opscode/chef-repo

gem install spatula (this is Trotter's tool)

spatula prepare db-server.yourcompany.com

spatula install my_database #this will look up the appropriate cookbook and install

...Rest of instructions are on the slides and I don't want to copy them word for word. They should soon be up on the Philly ETE Site.

The Chef Directory is really simple. It contains 'config,' 'cookbooks', 'roles', and 'custom-cookbooks' subdirectories. The cookbook directory contains recipes, files and templates (static or dynamic files to copy to places on your machine), attributes, and some others.

Trotter says the best possible place to start learning Chef is on their website, though not necessarily at the home page. Start with http://wiki.opscode.com/display/chef/Resources. This has the most relevant definitions and lots of example code to get you started.