Does anyone have an example k8s deployment with RBAC permissions to run something like `kubectl get --raw /apis/metrics.k8s.io/v1beta1/nodes` ? https://twitter.com/rothgar/status/1544934007397175297

README.md

This is a tested example.
Not all clusters will have the metrics API, but this will function for ones that do.

The deployment uses the bitnami/kubectl image. It runs "get node metrics" in a shell while loop that sleeps.

The Deployment's Pod-template uses a ServiceAccount that is ClusterRoleBound to a ClusterRole permitting the list and get verbs for the Node kind in the metrics.k8s.io API group.

Here's how to reproduce:

kubectl apply -f https://gist.githubusercontent.com/stealthybox/4b501b94c51a0421e8e84b6b440ca587/raw/52be01a73de42bafa93284e4501d8bbda67ead91/metrics-rbac-deploy.yaml

kubectl -n example get deploy,po
kubectl -n example logs -f deploy/metrics-fetcher

cleanup:

kubectl delete -f https://gist.githubusercontent.com/stealthybox/4b501b94c51a0421e8e84b6b440ca587/raw/52be01a73de42bafa93284e4501d8bbda67ead91/metrics-rbac-deploy.yaml

---

Note:
kubectl get --raw /apis/metrics.k8s.io/v1beta1/nodes and
kubectl get nodes.metrics.k8s.io -o json return the same objects.

However, they output different List types.

metrics-rbac-deploy.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: example
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: metrics-fetcher
  namespace: example
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: metrics-fetcher
rules:
- apiGroups:
  - metrics.k8s.io
  resources:
  - nodes
  verbs:
  - list
  - get
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: metrics-fetcher
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: metrics-fetcher
subjects:
- kind: ServiceAccount
  name: metrics-fetcher
  namespace: example
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: metrics-fetcher
  namespace: example
spec:
  selector:
    matchLabels:
      app: metrics-fetcher
  template:
    metadata:
      labels:
        app: metrics-fetcher
    spec:
      serviceAccountName: metrics-fetcher
      containers:
      - name: metrics-fetcher
        image: bitnami/kubectl
        command:
          - bash
          - -c
          - |
            while true
            do
              kubectl get --raw /apis/metrics.k8s.io/v1beta1/nodes
              echo
              echo 'sleeping...'
              sleep 10
              echo
            done
        resources:
          limits:
            memory: "128Mi"
            cpu: "500m"