CRI-O and Kata* Containers closer than ever

Sebastien Boeuf
May 3, 2018 · 2 min read

Everybody knows about CRI-O and how CRI calls are easily translated into OCI calls.

At the beginning, the project was known as Intel® Clear Containers. We worked closely with CRI-O maintainers to prevent regressions and seamlessly integrate with stacks that rely on the CRI interface, such as Kubernetes* and others. The CRI-O maintainers were open to our proposals and involved in Clear Containers integration.

A few months have passed since Kata Containers officially took over Clear Containers and the support from the CRI-O team has not weakened. In fact, their support is stronger now with the introduction of a Kata Containers build run on their repository.

What does this mean for developers?

Every pull request submitted to the CRI-O repository will be run through one of our Kata Containers builds. The changes will be gated by the build results, preventing any new patch from introducing regressions related to kata-runtime. Currently, runc is tested to prevent regressions in a similar way.

The kata-runtime test set is a subset of the runc tests, since it does not support all use cases supported by runc at this time. However, we’ll get there eventually. The great thing is that when CRI-O moves forward, we won’t have to worry about catching up on what’s already supported.

How is that a good thing?

From the CRI-O perspective, this is great news because it ensures full compatibility with kata-runtime, which I hope will attract more users to play with CRI-O.

From the Kata Containers perspective, this increases the pace to fill the runc gaps, allowing contributors to focus on those gaps. In the meantime, CRI-O CI will catch potential regression issues.

Kata: How get involved

Kata Containers is a fully open source project — check out Kata Containers on GitHub and join the channels below to find out how you can contribute.



Slack link:

Slack Invite:

IRC: #kata-dev on Freenode

Mailing list:

This work is licensed under a Creative Commons Attribution 4.0 International License

*Other names and brands may be claimed as the property of others.

CRI-O is a lightweight, optimized container runtime for…

Sebastien Boeuf

Written by



Sebastien Boeuf

Written by

Linux software engineer at Intel


CRI-O is a lightweight, optimized container runtime for Kubernetes. It's OCI (Open Container Initiative) compatible and an alternative to Docker or Moby. CRI-O supports OCI container images and can pull from any container registry. Visit for more information.

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