Project Maturity

cert-manager has wide adoption in the Kubernetes community with it being in use in both production and non-production clusters. The project is still in an alpha state where it has yet to reach v1.0.

API

The cert-manager API is currently in an v1alpha2 version and as such is subject to change. We foresee one beta version of v1beta1 at which we expect minimal changes, if any, to the next version release of v1. We expect to hit version v1 late 2019, early 2020.

Compatibility

cert-manager has a hard guarantee of compatibly with the current stable upstream Kubernetes version. Beyond this, cert-manager also aims to be compatible with versions down to N-4, where N is the current upstream version release. This means that if the current version is v0.16, cert-manager aims to be compatible with versions down to v0.12. This is done by running periodic end-to-end test jobs against each version of Kubernetes.

Versions lower than the current Kubernetes version down to N-4 is not guaranteed. Although considerations will be made to ensure compatibility with as many versions as possible, it is sometimes required to loose compatibility in the interest of furthering the feature set of cert-manager and making use of newer features available in upstream Kubernetes.

As of cert-manager version v0.11, the lowest Kubernetes version supported is v0.12.