<p>I am trying user cert-manager to manage certificate in OpenShift, but I saw some examples used apiVersion: cert-manager.io, some examples used apiVersion: certmanager.k8s.io.</p>

<p>I check them in my OpenShift, seems there is only certmanager.k8s.io, even though I have installed the latest cer-manager.</p>

<pre><code># oc get crd | grep certmanager.k8s.io
certificates.certmanager.k8s.io                             2020-01-07T17:27:09Z
challenges.certmanager.k8s.io                               2020-01-07T17:27:10Z
clusterissuers.certmanager.k8s.io                           2020-01-07T17:27:08Z
issuers.certmanager.k8s.io                                  2020-01-07T17:27:09Z
orders.certmanager.k8s.io                                   2020-01-07T17:27:09Z
</code></pre>

<p>I am confused, what difference for them? Which one should I use? Thanks your ideas.</p>

<blockquote>
  <p>Due to new policies in the upstream Kubernetes project, we have renamed the
  API group from certmanager.k8s.io to cert-manager.io.<a href="https://cert-manager.io/docs/release-notes/release-notes-0.11/#renamed-api-group" rel="nofollow noreferrer">renamed-api-group</a></p>
</blockquote>

<p>Here is the upstream k8s KEP <a href="https://github.com/kubernetes/enhancements/blob/master/keps/sig-api-machinery/20190612-crd-group-protection.md" rel="nofollow noreferrer">K8s group-protection </a></p>

<p>You should use <code>cert-manager.io</code> api group in the yaml.  </p>
