OpenSTF + Jenkins = Scalable In-House Device Sharing

I first learned about OpenSTF from a tweet by Square's Jake Wharton. It's frickin' awesome. I believe I've posted about this before but seriously go check it out if you're an Android developer or tester who has a pool of shared test devices to work with. It's FOSS and boss. Go check it out.

At the time of Jake's tweet, there was no integration between the awesome little project and my cluster of devices configured to host test automation in Jenkins. Because of the open source natures of both OpenSTF and Jenkins, and the robust plugin system on Jenkins, it seemed inevitable to me that a plugin would be written eventually to marry the two. I even speculated that I might write one if I got the chance.

Luckily for everyone that wasn't going to be necessary.

It's actually really straightforward to set up and easy to use but here are a couple of issues with work-arounds you might want to consider:

• Issue -The API key from OpenSTF for the plugin's global config is associated with the username on the OpenSTF service that created it.
• Solution - Create your API key on OpenSTF for the Jenkins Plugin using a service account with the name "Jenkins" so it is obvious who is using the device when a job configured with the plugin checks one out on the OpenSTF service.
• Issue - The OpenSTF Plugin uses the Android Emulator Plugin to manage device IO which means you can't run all your tests across all devices in a given pool in parallel with a normal job config.
• Solution - The suggested solution by the plugin maintainer is to use a matrix job but I find the Jenkins implementation of a matrix job to be a suboptimal experience. Instead, I prefer to configure my jobs in the following way:
• restrict it to the node hosting your OpenSTF service
• use the OpenSTF plugin to configure the job to use a single, specific device and name it in a semantically unique way that identifies the device as it's desired target (i.e. "testMyApp_Nexus5X_SDK24")
• use the "$ANDROID_SERIAL" environment variable in all shell script calls to adb (see my previous posts on how to set up Jenkins and devices to be scalable for examples of this).
• Granted, if you're running a job across dozens of devices, a Matrix Job might be a better config but in our case, less than 10 devices means single jobs work better visually and for discoverability

I may present on this at a future Seattle Android Developers meetup depending on timing and opportunity but if there's enough call for it here, I can update this post with a more elaborate description including screenshots and step-by-step instructions to fully illustrate my approach.