Dockershim removal is coming. Are you ready?
Author: Sergey Kanzhelev, Google. With reviews from Davanum Srinivas, Elana Hashman, Noah Kantrowitz, Rey Lejano.
Last year we announced that Dockershim is being deprecated: Dockershim Deprecation FAQ. Our current plan is to remove dockershim from the Kubernetes codebase soon. We are looking for feedback from you whether you are ready for dockershim removal and to ensure that you are ready when the time comes. Please fill out this survey: https://forms.gle/svCJmhvTv78jGdSx8.
The dockershim component that enables Docker as a Kubernetes container runtime is being deprecated in favor of runtimes that directly use the Container Runtime Interface created for Kubernetes. Many Kubernetes users have migrated to other container runtimes without problems. However we see that dockershim is still very popular. You may see some public numbers in recent Container Report from DataDog. Some Kubernetes hosting vendors just recently enabled other runtimes support (especially for Windows nodes). And we know that many third party tools vendors are still not ready: migrating telemetry and security agents.
At this point, we believe that there is feature parity between Docker and the other runtimes. Many end-users have used our migration guide and are running production workload using these different runtimes. The plan of record today is that dockershim will be removed in version 1.24, slated for release around April of next year. For those developing or running alpha and beta versions, dockershim will be removed in December at the beginning of the 1.24 release development cycle.
There is only one month left to give us feedback. We want you to tell us how ready you are.
We are collecting opinions through this survey: https://forms.gle/svCJmhvTv78jGdSx8 To better understand preparedness for the dockershim removal, our survey is asking the version of Kubernetes you are currently using, and an estimate of when you think you will adopt Kubernetes 1.24. All the aggregated information on dockershim removal readiness will be published. Free form comments will be reviewed by SIG Node leadership. If you want to discuss any details of migrating from dockershim, report bugs or adoption blockers, you can use one of the SIG Node contact options any time: https://github.com/kubernetes/community/tree/master/sig-node#contact
Kubernetes is a mature project. This deprecation is another step in the effort to get away from permanent beta features and providing more stability and compatibility guarantees. With the migration from dockershim you will get more flexibility and choice of container runtime features as well as less dependencies of your apps on specific underlying technology. Please take time to review the dockershim migration documentation and consult your Kubernetes hosting vendor (if you have one) what container runtime options are available for you. Read up container runtime documentation with instructions on how to use containerd and CRI-O to help prepare you when you're ready to upgrade to 1.24. CRI-O, containerd, and Docker with Mirantis cri-dockerd are not the only container runtime options, we encourage you to explore the CNCF landscape on container runtimes in case another suits you better.