Merge pull request #7925 from hickeyma/fix/add-user-error

fix(upgrade): Add an improved user error message for removed Kubernetes APIs

pkg/action/upgrade.go

@@ -233,6 +233,13 @@ func (u *Upgrade) prepareUpgrade(name string, chart *chart.Chart, vals map[strin
 func (u *Upgrade) performUpgrade(originalRelease, upgradedRelease *release.Release) (*release.Release, error) {
 	current, err := u.cfg.KubeClient.Build(bytes.NewBufferString(originalRelease.Manifest), false)
 	if err != nil {
+		// Checking for removed Kubernetes API error so can provide a more informative error message to the user
+		// Ref: https://github.com/helm/helm/issues/7219
+		if strings.Contains(err.Error(), "unable to recognize \"\": no matches for kind") {
+			return upgradedRelease, errors.Wrap(err, "current release manifest contains removed kubernetes api(s) for this "+
+				"kubernetes version and it is therefore unable to build the kubernetes "+
+				"objects for performing the diff. error from kubernetes")
+		}
 		return upgradedRelease, errors.Wrap(err, "unable to build kubernetes objects from current release manifest")
 	}
 	target, err := u.cfg.KubeClient.Build(bytes.NewBufferString(upgradedRelease.Manifest), !u.DisableOpenAPIValidation)