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Mozilla Corporation prides itself on keeping the internet open and accessible to all. With the rise of smartphone and mobile internet, it was a natural move for the Mozilla team to bring its Firefox Browser to Android and iOS users. Today over a billion web browser users around the world are enjoying the Firefox experience at any time, be it on a desktop, a mobile phone or a tablet.

Bringing the same level of Firefox Desktop experience to Firefox Mobile has always been a large focus for Mozilla’s development efforts. Knowing that, the automation team led by Joel Maher, Lead Automation & Tools at Mozilla wanted to go through the full set of tests on a variety of physical phones with different combinations of hardware and software.

Unable to Scale Real Device Testing with a Homegrown Device Lab

The company started the Firefox Android project in 2012 and the automation team built a large variety of automation scripts to run against their in-house real devices.

“It didn’t go well. The phones were distributed at different desks in the office or people who were working remotely. Running tests became very dependent on that person being around to fix the phones in case of any issues. We started moving to emulators,” explained Joel.

Due to the lack of a robust real device testing solution, the team opted to testing on emulators since it was getting impractical to run tests on physical devices.

In 2017, the year prior to adopting BitBar Private Cloud, the team was hosting a half of a rack of devices at Mozilla’s Mountain View office.

“This time we had set up 30 Android phones connected to a couple of servers in a closet. We were able to run the tests, but devices would go offline in any given day,” explained Joel. “We didn’t have any paid staff to look at the devices. And when some phones went offline, it always required somebody hands-on to get into the closet and spend a half hour getting those phones online. It wasn’t a robust setup and we were frustrated with that. So we started to consider other options.”

The frustration with the homegrown testing solution led the team to think about outsourcing device hosting and management while allowing them to run test automation on real devices.

Since we didn’t have any paid staff to look at the devices, when some devices went offline, it always required somebody to get into the closet and spend a half hour getting these phones online. It wasn’t a robust setup and we started to consider other options.

Joel Maher, Lead Automation & Tools at Mozilla

Putting BitBar to Work Out Unique Testing Requirements

Joel’s team started to look at a variety of vendors including Google Firebase and Amazon Device Farm. But none of these players could meet Mozilla’s unique testing needs.

“Our web browser tests are not built using APIs. Instead, all of our commands are built into a browser, and we need to load a webpage from a server. So that doesn’t work with the typical way to run APIs on a phone,” explained Joel, “What we are testing is if we can load this webpage and if it can render properly. Because of that, everything is dependent upon a certain framework or a list of different automation frameworks.” In addition to necessary support for custom frameworks, Joel’s team needed rooted phones to make tests run smoother and that was another big barrier to getting into any of other players.

Given the past success that BitBar did custom OS flashing (Firefox OS) on the Android devices for Mozilla, Joel’s team reached out to the BitBar team.

“We didn’t have Dockerized containers nor high quality hubs connecting them. We just got by with what we had as we didn’t have time to experiment and make things better,” said Joel, “BitBar came to our mind for investigation. We worked with Sakari (CTO at BitBar) who helped us set up a Docker image container connected directly to a phone in their Private Cloud. And it ended up being great.”

The POC with BitBar set Joel’s team up for success in a much faster way and it turned out to be a more reliable and repeatable process than what Mozilla had.

We worked with Sakari (CTO at BitBar) who helped us set up a Docker image container connected directly to a phone in their Private Cloud. And it ended up being great.

Realizing the Full Potential of BitBar’s Technologies for CI/CD and Full Automation

Every week, Joel’s team has about 1,100 builds in the integration and release branches. And they have a ‘try server’ for developers to test their stuff before it gets checked in. So in a given week, Mozilla has close to 2,500 builds in total. That creates a lot of testing every week.

To improve test efficiency and support its continuous integration and release processes, Mozilla created Taskcluster, an easy-to-configure and robust scheduling software that helps to distribute test runs.

“For a full set of tests against one Android build, we would launch a hundred emulator jobs and 40 tasks on BitBar’s real devices. If we were to run all of them sequentially, that would take 75 hours to complete – 60 hours for the emulators and 15 hours for real devices – without repeating them,” explained Joel, “So Mozilla went on its own and created Taskcluster to distribute multiple tests across available Workers (a Worker could be an emulator or a phone at BitBar) at the same time. Now we’ve taken that 75 hours down to 5 hours to get through a test cycle.”

For real device testing, there’s a proxy that will call a BitBar API and insert the Taskcluster test jobs into the proper queue at BitBar. With Taskcluster managing test orchestration and BitBar’s support for unlimited device concurrency, Joel’s team has brought 15 hours of real device testing down to average of 2 hours.

To help Mozilla enhance its full automation and continuous testing practice, BitBar is hosting a Private Cloud with a multitude of devices, dedicated to Mozilla, in its Santa Clara data center.

“As far as BitBar’s real device environment, we’re over 90% utilization during the peak hours. During the core workday starting from 6 a.m. to 8 p.m. Pacific Time, we’re guaranteed to have test jobs in the queue,” said Joel. “We’ve always been running full automation. BitBar’s solution has enabled us to scale up our automated testing. We’re running a much higher throughput and these tests are depended on by a much larger volume of people.”

He added, “It was hard to scale our testing efforts before switching to BitBar. We needed better organization and we didn’t have good tools. If one of our servers needed updating, for example, all eight devices connected to it would go down. Now we run test automation on a hundred phones hosted by BitBar, and we have alerts on the phone status online. It’s a much more robust environment where it’s more self-healing and we’ve got more eyes on it.”

Using the BitBar API, the automation team at Mozilla was able to monitor the system and infrastructure to get proper alerts on device status.