[distribution] Update README for 2.37.0: Redis removal, upgrade hook fallback, and Kubernetes version fix (INST-21313)

Author: nagarajuv-jfrog

stable/distribution/README.md

@@ -3,13 +3,15 @@
 **IMPORTANT!** Our Helm Chart docs have moved to our main documentation site. Below you will find the basic instructions for installing Distribution. For all other information, refer to [Installing Distribution](https://jfrog.com/help/r/jfrog-installation-setup-documentation/installing-distribution).
 
 ## Prerequisites Details
-* Kubernetes 1.19+
+* Kubernetes 1.23+
 
 ## Chart Details
 This chart does the following:
 * Deploy PostgreSQL database
 * Deploy distribution
 
+> **Note:** From Distribution 2.37.0, Redis is no longer included in this chart. For more information, see the [Distribution 2.37.0 release notes](https://docs.jfrog.com/releases/docs/distribution-release-notes#distribution-2370).
+
 ## Requirements
 - A running Kubernetes cluster
 - Dynamic storage provisioning enabled
@@ -46,6 +48,18 @@ For small configurations :
 helm upgrade --install distribution jfrog/distribution -f sizing/distribution-small.yaml --namespace distribution --create-namespace
 ```
 
+## Upgrading to Distribution 2.37.0 or Later
+
+From Distribution 2.37.0, Redis has been removed from the chart. For more details, please refer to the [Distribution 2.37.0 release notes](https://docs.jfrog.com/releases/docs/distribution-release-notes#distribution-2370).
+
+When upgrading from a version prior to 2.37.0, a pre-upgrade webhook (`distribution-upgrade-hook`) is automatically executed. This webhook handles the migration by deleting the existing StatefulSet with `--cascade=orphan` (preserving running pods) to allow the updated spec — which no longer includes Redis — to be applied cleanly.
+
+In most cases, no manual intervention is required. However, if the hook job fails (for example, due to RBAC permissions or image pull issues), you may need to manually delete the StatefulSet before retrying the upgrade:
+
+```bash
+kubectl delete statefulset <release-name>-distribution --cascade=orphan -n <namespace>
+```
+
 ## Uninstalling Distribution
 
 **IMPORTANT:** Uninstalling distribution using the commands below will also delete your data volumes and you will lose all of your data. You must back up all this information before deletion.