I’ve recently set up several CI Joe instances to handle our various projects at Eden. We’ve been using Integrity for several months, but it’s caused us a few problems and I yearned for something simpler. CI Joe is about as simple as it gets, and the brevity of the code encourages hacking and customisation.
I’ve now set it up to run multiple Joes using Rack and Passenger for the various different projects we run. Being as I didn’t find much on the net about setting up CI Joe in this way, I thought a fairly detailed howto would be helpful. Let me know how you get on with it.
Our structure looks like this:
The main Passenger vhost is set up for the cijoe/ directory, and each CI Joe installation has to be symlinked in this way for it to pick them all up.
We put the following file in /etc/httpd/sites.d/ci.conf:
The key bits here are as follows:
- Passenger by default runs ruby processes without a path set, so set the path so CI Joe can call git correctly.
- RackBaseURI is used to start multiple Joe’s, one for each project.
- PassengerMaxInstancesPerApp needs to be set to one, otherwise you’ll get weird results.
- Set your PassengerMaxPoolSize to exactly the number of Joes you’ve got running, so Passenger doesn’t kill the build processes.
- Clear the RAILS_RELATIVE_URL_ROOT environment variable: this will be set by the RackBaseURI calls, and will bleed into your tests, break any that rely on absolute paths.
The config.ru we’re using for the individual Joes is as follows:
We keep this in the cijoe-repos/ folder, and symlink it into the different project folders. We also apply a monkey patch to the run_hooks method to strip out backticks: these can stop the hooks running correctly.
If you want to use our build hooks, read on, otherwise you can safely skip the next section.
We have one master build hook script living in cijoe-repos/ which we symlink everywhere. This reads the file structure to find out which project we’re in, and its own symlinked name to work out what’s happened. It then HTTP POSTs the results to our dashboard application:
It’s not very pretty: my bash-fu isn’t up to much. Suggestions for improvement are welcome.
The credentials file mentioned above is a file which lives in cijoe-repos/. It has one line in it:
These are the user authentication credentials for the POST to your dashboard.
Adding a project
To add a project to the structure:
Then you need to poke the apache vhost configuration to add another RackBaseURI and up the number of processes by 1.
This setup works well for us. We’ve only been running it a few days, but it does feel cleaner and more manageable that the old Integrity system. It’s nice to have each server in seperate processes, with a fully customisable dashboard distinct from the build servers themselves.
With this setup a project could even choose to run a different server: as long as a config.ru file was defined and the HTTP POST notifications are made correctly, it will all work the same way.
I’d love to make it a bit less complex to set up new projects. If you have any ideas for how to improve the setup then do let me know!