Easily setup a docker-based jenkins CI on AWS

[crohr]

CloudFormation templates are a great way to deploy stuff on amazon web services, and a docker-based jenkins image is a great way to document what's installed on your CI server. Let's see how this works.

But first, some background:

If you've ever managed a Jenkins CI in the past, you'll know that it quickly becomes harder and harder to keep track of all the dependencies that need to be installed so that your CI jobs can run. Even if you started managing it with Puppet or Chef, sometimes it was just too tempting to apt-get install that missing dependency directly on the server to keep your developers happy with the 120th dependency required for running their tests.

Then, if you needed to replicate your setup on another machine, you would most likely spend a lot of time tracking down undocumented dependencies that you need to reinstall.

Let's see how you can easily install a Jenkins CI on AWS, and keep it lean and self-documented.

CloudFormation template to install a jenkins server

CloudFormation is a tool provided by AWS, which allows to describe stacks to be launched in a declarative (JSON) format. If you've never used it, you're missing out on one of the best features of AWS.

For this article we'll use the template provided by The Factory, which will deploy an EC2 instance behind an Elastic Load Balancer, and register a new record in a Route53 zone that points to it.