Runtime: Evaluate Kata + Podman

[egernst]

I'm confident integration of Kata into podman is feasible, and we should have a "how-to" guide and some level of automated testing available to ensure the 'how-to' guides' functionality.

Futher, it would be good to evaluate this in the context of running kata rootless. This should be feasible with overlay2, though there would likely be complications wrt devicemapper.

[egernst]

/cc @mcastelino @gabibeyer

[egernst]

Any progress on this front? @gabibeyer can you summarize your findings thus far?

[gabibeyer]

kata seems to work pretty seamlessly with podman as long as selinux is disabled (which already seems to be a reported issue within kata). I have gotten it running in fedora 28, trying ubuntu bionic currently just to see if there are differences.

[mcastelino]

@gabibeyer can you describe your setup. Also the final goal is to run Kata as rootless with podman.

We need to ensure we do not create files with root uid/gid on the host side when using overlay. Also ensure that the other files like resolv.conf etc do not end up being root when modified.

[gabibeyer]

@mcastelino right, that is not yet rootless,. Should I still describe my setup if it is not yet the rootless implementation?

[gabibeyer]

https://gist.github.com/gabibeyer/ae3f8ee5e7ebc4e1db9d9c26119ca861

[gabibeyer]

Modifications to podman and slirp4netns are in progress for a rootless podman + kata integration

[gabibeyer]

• [ ] #1827 - Configurable paths to be at rootless or default location
• [ ] #1874 - Add rootless logic to 1. Check if kata is being ran rootlessly, and 2. Get the rootless runtime dir
• [ ] Make usage of cgroups configurable
• [ ] Create tap device structure intended for tun/tap devices

[alicefr]

Any plans to add tests for podman?

[jodh-intel]

@alicefr - we're hoping to convert https://github.com/kata-containers/documentation/pull/565 into both a document and a test (by "executing" the document commands). However, if you have cycles to help write some more comprehensive tests, that would be great! :smile:

[alicefr]

@jodh-intel thx!Nice! There are some tests in the podman repo at https://github.com/containers/libpod/tree/master/test. I'm not sure if they can be extended to be used with kata. I'm trying to check if podman+kata works on s390x. I'll have a look after to their testsuite.