How Giant Swarm replaced their engines mid-flight while maintaining a steady cruising altitude

Installing Linux on a new PC isn’t that hard, right? How about replacing the operating system across a fleet of thousands of virtual machines across multiple clouds and on-premises installations, with major global enterprise customers relying on you to keep their infrastructure running 24x7?

This was the challenge that faced Giant Swarm as they realized CoreOS Container Linux, on which their managed Kubernetes service was based, had been declared end of life — and decided to migrate to Flatcar Container Linux, with the help of Kinvolk. With responsibility for the production clusters of high-profile customers such as Adidas, Shutterstock, and Vodafone, they couldn’t get this wrong.

A couple of weeks ago, I had the opportunity to share a virtual stage with Salvo Mazzarino of Giant Swarm, telling the story of how they decided on their migration strategy, the challenges of implementing it across multiple clouds including AWS, Azure and on-prem (KVM), and the lessons learned from the process.

“We embraced CoreOS already in 2015. The reason why we did this was because we needed an immutable infrastructure,” said Salvo during the meetup. “Once CoreOS announced end of life, we needed to find another way… We said goodbye to CoreOS and the graph [of Flatcar deployments] is now at 100%... This was possible thanks to the great sponsorship that we have together with Kinvolk.”

See the video of our presentation to find out all the gory details of the migration process – and many thanks to the lovely Software Circus folks for inviting us to their meetup!

_{Image created using free vectors by Vecteezy}