Changelog for Kubernetes 1.18

Versions

• Kubernetes 1.18.9
• Nginx-ingress: 0.40.0
• Certmanager: 1.0.3

Major changes

• Moved the tcp-services configmap used by our ingress controller to the default namespace.

Deprecations

• Ingress api extensions/v1beta1 will be removed in kubernetes 1.22
• RBAC api rbac.authorization.k8s.io/v1alpha1 and rbac.authorization.k8s.io/v1beta1 will be removed in kubernetes 1.20. The apis are replaced with rbac.authorization.k8s.io/v1.
• The node label beta.kubernetes.io/instance-type will be rmeoved in an uppcomig release. Use node.kubernetes.io/instance-type instead.
• Certmanager api v1alpha2, v1alpha3 and v1beta1 will be removed in a future release. We strongly recommend that you upgrade to the new v1 api
• Accessing the Kubernetes dashboard over the Kubernetes API. This feature will not be added to new clusters however if your cluster already has this available it will continue working until Kubernetes 1.19

Removals

• Some older deprecated metrics, more information regarding this can be found in the official Kubernetes changelog: Link to Kubernetes changelog

Is downtime expected

For this upgrade we expect a shorter downtime on the ingress. The downtime on the ingress should be no longer than 5 minutes and hopefully even under 1 minute in length.

The upgrade drains (moving all workload from) one node at the time, patches that node and brings in back in the cluster. First after all deployments and statefulsets are running again we will continue on with the next node.

Known issues

Custom node taints and labels lost during upgrade

All custom taints and labels on nodes are lost during upgrade.

Snapshots is not working

There is currently a limitation in the snapshot controller not making it topology aware.

Resize problem on volumes created before Kubernetes 1.16

Volume expansion sometimes fails on volumes created before Kubernetes 1.16.

A workaround exists by adding an annotation on the affected volumes, an example command:

kubectl annotate --overwrite pvc PVCNAME volume.kubernetes.io/storage-resizer=cinder.csi.openstack.org