Docker + Arm Virtual Meetup Recap: Building Multi-arch Apps with Buildx

Sep 20 2019

Docker support for cross-platform applications is better than ever. At this month’s Docker Virtual Meetup, we featured Docker Architect Elton Stoneman showing how to build and run truly cross-platform apps using Docker’s buildx functionality. 

With Docker Desktop, you can now describe all the compilation and packaging steps for your app in a single Dockerfile, and use it to build an image that will run on Linux, Windows, Intel and Arm – 32-bit and 64-bit. In the video, Elton covers the Docker runtime and its understanding of OS and CPU architecture, together with the concept of multi-architecture images and manifests.

The key takeaways from the meetup on using buildx:

  • Everything should be multi-platform
  • Always use multi-stage Dockerfiles 
  • buildx is experimental but solid (based on BuildKit)
  • Alternatively use docker manifest — also experimental

Not a Docker Desktop user? Jason Andrews, a Solutions Director at Arm, posted this great article on how to setup buildx using Docker Community Engine on Linux

Check out the full meetup on Docker’s YouTube Channel:

You can also access the demo repo here. The sample code for this meetup is from Elton’s latest book, Learn Docker in a Month of Lunches, an accessible task-focused guide to Docker on Linux, Windows, or Mac systems. In it, you’ll learn practical Docker skills to help you tackle the challenges of modern IT, from cloud migration and microservices to handling legacy systems. There’s no excessive theory or niche-use cases — just a quick-and-easy guide to the essentials of Docker you’ll use every day (use the code webdoc40 for 40% off).

To get started building multi-arch apps today: