Create an admin kubeconfig

create.sh

#!/usr/bin/env bash
set -ex

kubectl create serviceaccount admin
kubectl create clusterrolebinding admin --clusterrole=cluster-admin --serviceaccount=default:admin

SECRET_NAME=$(kubectl get sa admin -o=jsonpath='{.secrets[0].name}')
TOKEN=$(kubectl get secret "${SECRET_NAME}" -ojsonpath='{.data.token}' | base64 -d)
CA=$(kubectl get secret "${SECRET_NAME}" -ojsonpath='{.data.ca\.crt}')
CURRENT_CONTEXT=$(kubectl config current-context)
CURRENT_CLUSTER=$(kubectl config view --raw -o=go-template='{{range .contexts}}{{if eq .name "'''"${CURRENT_CONTEXT}"'''"}}{{ index .context "cluster" }}{{end}}{{end}}')
CLUSTER_SERVER=$(kubectl config view --raw -o=go-template='{{range .clusters}}{{if eq .name "'''"${CURRENT_CLUSTER}"'''"}}{{ .cluster.server }}{{end}}{{ end }}')

cat << EOF > admin.yaml
apiVersion: v1
kind: Config
current-context: ${CURRENT_CONTEXT}
contexts:
- name: ${CURRENT_CONTEXT}
  context:
    cluster: ${CURRENT_CONTEXT}
    user: admin
    namespace: default
clusters:
- name: ${CURRENT_CONTEXT}
  cluster:
    certificate-authority-data: ${CA}
    server: ${CLUSTER_SERVER}
users:
- name: admin
  user:
    token: ${TOKEN}
EOF