Kubernetes Part VI - Helm Package Manager

This past week, my colleague has introduced me to something called Helm, which is sort of like a "pip" for Python. It manages Kubernetes packages (it is a Kubernetes Package Manager).

The reason this was introduced:
We found SEVERAL github repos with Prometheus Metrics in them, and they were not at all consistent.

• Kubernetes had one
• There was another one at a stefanprod project
• There was yet a third called "incubator"

My colleague, through relentless research, figured out (or decided) that the one installed through Helm was the best one.

This meant I had to understand what Helm is. Helm is divided into a client (Helm), a server (Tiller), and you install packages (Charts). I guess it's a maritime themed concept, although I don't know why they can't call a package a package (copyright reasons maybe?).

So - I installed Helm, and that went smoothly enough. I installed it on my Kubernetes Master.  I also downloaded a bunch of Charts off the stable release in GitHub (Prometheus is one of these). These all sit in a /stable directory (after the git clone, ./charts/stable).

When I came back in, and wanted to pick back up, I wasn't sure if I had installed Prometheus or not. So I ran a "helm list", and got the following error:

Error: configmaps is forbidden: User "system:serviceaccount:kube-system:default" cannot list configmaps in the namespace "kube-system"

Yikes. For a newbie, this looked scary. Fortunately Google had a fix for this on a StackOverflow page.

I had to run these commands:

kubectl create serviceaccount --namespace kube-system tiller
kubectl create clusterrolebinding tiller-cluster-rule --clusterrole=cluster-admin --serviceaccount=kube-system:tiller
kubectl patch deploy --namespace kube-system tiller-deploy -p '{"spec":{"template":{"spec":{"serviceAccount":"tiller"}}}}'      
helm init --service-account tiller --upgrade

These seemed to work. The "helm list" command showed no results, though, so I guess I need to install the prometheus package (sorry...chart) after all with helm now.

But, more importantly, I really need to take some time to understand what we just ran above, with regards to this stuff above; the cluster role bindings, et al.