University of Arizona Libraries TeSS

We're committed to delivering the most reliable websites, software, and services possible. That's why we've chosen to make continuous integration a priority for our technical infrastructure. Continuous integration is a software development practice that helps developers catch problems early by requiring them to merge their code into a shared environment, called a CI (continuous integration) server, that runs automated tests. The server will report any problems back to the developer so they can fix the problem before deploying the code to production.

We've used CI for many years, but lately we noticed that there were a lot of issues with our system. It was prone to breaking and time consuming to fix. We needed to revive our continuous integration environment to make it more useful to our developers and in turn make our products better.

The first step was to upgrade our installation of Jenkins, the open source software that we use to automate building and testing our code. After that, we worked on integrating Jenkins with other services. We really wanted to be able to use UA NetID to log in to the Jenkins admin interface, so we set up the Jenkins CAS Plugin to talk to WebAuth to make authentication a breeze. Next, we focused on improving the integration between Jenkins and Slack, a handy chat app we use for a lot of our communication. We were able to set up Slack so that it would notify developers when the tests failed and were even able to tag specific users so that they would get phone alerts when there was a problem. The result is that we're faster than even when responding to bugs or service outages.

The most fragile part of our CI environment was our use of Selenium. Selenium is a browser automation tool that simulates how a user interacts with a website. Although it can be very useful, it's also very picky about which browser version you're using. We often had problems where our Selenium-based tests wouldn't work because they required specific versions of Firefox that were no longer installed due to automatic updates.

Thankfully, Docker provided an excellent solution to this problem. Docker is a containerization tool that allows us to run system processes in an isolated environment. This means that we're able to run Selenium with the correct version of Firefox without having to worry about automated updates breaking things.

These improvements to our CI environment have already paid off by saving us time and catching bugs before they can affect our users. We hope to continuously improve our continuous integration environment to give our users the best experience possible!