Use "k8s-app=kube-controller-manager" instead of "k8s-app=kube-controller"

[rutsky]

Some tools such as Prometheus Operator rely on k8s-app labels values.

k8s-app=kube-controller-manager label is used at least by bootkube, kops and as far as @brancz can tell the manifests in kubernetes/kubernetes.

I suggest to switch to using k8s-app=kube-controller-manager label.

/cc: @brancz

[brancz]

I just opened an issue on standardizing this as this is not the first time a tool as slightly inconsistent about this.

For the reference: kubernetes/kubernetes#42887

[ant31]

@brancz Do you think you can switch on using the labels format proposed on kubernetes/community#300 in prom-controller and validate it as a long term/official label.
Then we can sync with community (kops/bootkube) to perform the switch.

[gdmello]

Any update on this? kops seems to use k8s-app: kube-controller-manager as well.
It would be good to standardize on these labels.

[Starefossen]

Keep in mind how these changes affects upgrade of existing Kubespray installations. A similar change of labels and names was done for kube-dns in #1372 which broke upgrades.

[mattymo]

The issue with kube-dns was related to changing the resource name. This is just a label and should be harmless