Compatibility matrix: CRI-O ⬄ Kubernetes
CRI-O and Kubernetes follow the same release cycle and deprecation policy. For more information visit the Kubernetes versioning documentation.
|Version - Branch||Kubernetes branch/version||Maintenance status|
|CRI-O 1.17.x - release-1.17||Kubernetes 1.17 branch, v1.17.x||=|
|CRI-O 1.18.x - release-1.18||Kubernetes 1.18 branch, v1.18.x||=|
|CRI-O 1.19.x - release-1.19||Kubernetes 1.19 branch, v1.19.x||=|
|CRI-O HEAD - master||Kubernetes master branch||✓|
✓Changes in main Kubernetes repo about CRI are actively implemented in CRI-O
=Maintenance is manual, only bugs will be patched.
The release notes for CRI-O are hand-crafted and can be continuously retrieved
from our GitHub pages website.
What is the scope of this project?
CRI-O is meant to provide an integration path between OCI conformant runtimes and the kubelet.
Specifically, it implements the Kubelet Container Runtime Interface (CRI) using OCI conformant runtimes.
The scope of CRI-O is tied to the scope of the CRI.
At a high level, we expect the scope of CRI-O to be restricted to the following functionalities:
- Support multiple image formats including the existing Docker image format
- Support for multiple means to download images including trust & image verification
- Container image management (managing image layers, overlay filesystems, etc)
- Container process lifecycle management
- Monitoring and logging required to satisfy the CRI
- Resource isolation as required by the CRI
What is not in scope for this project?
- Building, signing and pushing images to various image storages
- A CLI utility for interacting with CRI-O. Any CLIs built as part of this project are only meant for testing this project and there will be no guarantees on the backward compatibility with it.
This is an implementation of the Kubernetes Container Runtime Interface (CRI) that will allow Kubernetes to directly launch and manage Open Container Initiative (OCI) containers.
The plan is to use OCI projects and best of breed libraries for different aspects:
- Runtime: runc (or any OCI runtime-spec implementation) and oci runtime tools
- Images: Image management using containers/image
- Storage: Storage and management of image layers using containers/storage
- Networking: Networking support through use of CNI