How to rollback the Kubernetes version of a Rancher v2.x provisioned cluster

Task

This article details how to rollback the Kubernetes version of a Rancher v2.x provisioned cluster.

Important Note:

A Kubernetes Cluster Rollback will most definitely cause downtime in the cluster, as you are restoring a snapshot from before the upgrade and the cluster will have to reconcile state.

Pre-requisites

• In order to rollback your Kubernetes cluster version upgrade, you need to have first taken an etcd snapshot from before the upgrade. You should keep the reference to the snapshot name that was created as your "pre-upgrade" snapshot. In my cluster which has cluster ID: c-q8st7 , my snapshot name was c-q8st7-ml-qdxdh. Our example upgrade is from v1.14.9-rancher1-2 to v1.15.7-rancher1-1.

Rollback operation

In order to rollback, you must:

1. Edit Cluster
2. Edit as YAML
3. Set kubernetes_version back to v1.14.9-rancher1-2 (or whatever your desired restore version is)

4. Find the restore key in the YAML.

   You will need to update the following configuration:

   rancher_kubernetes_engine_config:
       restore:
       restore: false

   You'll want to closely model the following:

   rancher_kubernetes_engine_config:
       restore:
       restore: true
       snapshot_name: "c-q8st7:c-q8st7-ml-qdxdh"

   Note the snapshot_name has the cluster ID prefixed to it with a : .

5. Finally, you can save the cluster, and observe the snapshot restore + K8s version rollback occur.