Upgrade from 1.4.x to 1.5.x on Azure failing for missing Azure Client Secret

Products

• Azure VMware Solution

Issue/Introduction

Symptoms:
When trying to upgrade TKGm Environment from v 1.4.x to 1.5.x is failing with below error 

Applying patch to resource k8smgtlab0 of type *v1beta1.Cluster ...
unable to find azure-image config in user configuration file, using it from BoM files
no os options provided, selecting based on default os options
consuming Azure Image info: { vmware-inc tkg-capi k8s-1dot22dot5-ubuntu-2004 true 2022.01.27 {ubuntu 20.04 amd64} map[]}
Error: unable to upgrade management cluster: failed to update additional addon components: unable to get cluster configuration: unable to get template:
- base64.encode: expected a string, but was NoneType
in <toplevel>
overlay.yaml:333 | clientSecret: #@ base64.encode(data.values.AZURE_CLIENT_SECRET)

Environment

VMware Tanzu Kubernetes Grid 1.x

Resolution

Fix will be included in TKG v1.5.3 

Workaround:

AZURE_CLIENT_SECRET needs to be set when upgrading an Azure cluster from 1.4.x to 1.5.x. This can be done two ways

• Run Tanzu cluster upgrade command by including AZURE_CLIENT_SECRET 

AZURE_CLIENT_SECRET=<secret> tanzu cluster upgrade

• Perform export on jumpbox by running below command and then run upgrade

export AZURE_CLIENT_SECRET=<secret>