Upgrading Longhorn from Helm 2 in Rancher 2.6 the hard-way

Long ago, I installed Longhorn onto my Kubernetes cluster using Helm 2. Then eventually Helm 3 was released and helm 2to3 was made available. However, I was not able to use helm 2to3 for whatever reason because Rancher didn’t deploy Tiller in the way that this CLI expected. Additionally, Rancher did not provide an upgrade mechanism to handle this. Eventually Rancher 2.6 was released which entirely dropped Helm 2 support and I was stuck with a cluster where Longhorn was deployed, but not managed by a working Helm installation.

This blog post outlines how you can recover Longhorn and upgrade it to Helm 3 without deleting all your volumes. This guide isn’t specific to Rancher 2.6.

Continue reading “Upgrading Longhorn from Helm 2 in Rancher 2.6 the hard-way”