After a helm upgrade failed subsequent releases / upgrades to the helm chart returned the following error message:
Error: UPGRADE FAILED: another operation (install/upgrade/rollback) is in progress
In order to determine the problematic release revision issue:
helm history <release-name> -n <namespace>
The above error happened due to revision 5 being stuck on the 'pending-upgrade' status.
We can roll back the release one of the following ways:
helm rollback <release-name> 0 -n <namespace>
or (explicitly define the revision number):
helm rollback <release-name> 4 -n <namespace>