Helm how to delete bad deployment?

At some point everyone screws things up, so how do you fix it?  I had done a Ceph deployment using Helm on our Kubernetes cluster, but then realized I missed a setting a delete the namespace which in turn remove all the pods from underneath of Helm.  Then when I tried to properly delete using

helm delete --purge ceph

But, it isn’t working, keeps returning with a timeout, with an error message

Error: transport is closing

I can see my Ceph test deployment is still known by Helm, and didn’t get removed.

$ helm list
NAME        	REVISION	UPDATED                 	STATUS  	CHART             	NAMESPACE  
ceph        	1       	Sun Mar 18 03:03:41 2018	DEPLOYED	ceph-0.1.0        	ceph       
cert-manager	1       	Tue Mar 13 02:29:27 2018	DEPLOYED	cert-manager-0.2.2	kube-system

So, how do i get Helm to forget about the test installation that I had already deleted the namespace without properly doing a helm delete?

There’s a config map still stored by Helm in Kubernetes which we can delete.

$ kubectl get cm --all-namespaces
NAMESPACE     NAME                                 DATA      AGE
kube-public   cluster-info                         2         15d
kube-system   calico-config                        3         15d
kube-system   ceph.v1                              1         1d
kube-system   cert-manager.v1                      1         6d
kube-system   coredns                              1         6d
kube-system   extension-apiserver-authentication   6         15d
kube-system   kube-proxy                           2         15d
kube-system   kubeadm-config                       1         15d
kube-system   kubernetes-dashboard-settings        1         3d

You see the ceph.v1 ConfigMap, if we remove this object, we can then see Helm has forgotten about the installation that I screwed up.

$ kubectl delete cm ceph.v1 -n kube-system

You’ll see that it’s delete now.

$ helm list
NAME        	REVISION	UPDATED                 	STATUS  	CHART             	NAMESPACE  
cert-manager	1       	Tue Mar 13 02:29:27 2018	DEPLOYED	cert-manager-0.2.2	kube-system

We should be good now to try to redeploy my Ceph test once again.