How to deploy controller into the cluster

[kubernetes]

How to deploy controller into the cluster

[barry8schneider]

I found a few examples

Kubeless - use a Custom Resource Definition to be able to create functions as custom kubernetes resources. Then run an in-cluster controller that watches these custom resource - could this technique be incorporated into the sample?

kubewatch - A kubewatch container will be created along with kubectl sidecar container in order to reach the API server.

[nikhita]

Then run an in-cluster controller that watches these custom resource - could this technique be incorporated into the sample?

Not sure I follow, can you elaborate on how the in-cluster controller works in this case?

/cc @sttts @munnerz

[sttts]

The example uses BuildConfigFromFlags which in turn calls InClusterConfig (https://github.com/kubernetes/client-go/blob/master/tools/clientcmd/client_config.go#L553). So it should work in a pod. If it doesn't, it's a bug.

[radu-munteanu]

All controllers can be run outside K8s or inside, as an unique pod deployed on master. They use API calls to communicate with the cluster. For testing purposes, it's just easier to use it locally, rather than package it into a container and the run it as a pod.