Create a kubeconfig for an existing serviceaccount in kubernetes

gen-kubeconfig.sh

#!/bin/bash

# your server name goes here
server=https://my.k8s.cluster:6443
# the name of the secret containing the service account token goes here
name=super-secret-token-2l269
# the namespace containing the secret
namespace=kube-system

# don't touch this!
ca=$(kubectl get -n $namespace secret/$name -o jsonpath='{.data.ca\.crt}' | base64 --decode)
token=$(kubectl get -n $namespace secret/$name -o jsonpath='{.data.token}' | base64 --decode)

echo "
apiVersion: v1
kind: Config
clusters:
- name: default-cluster
  cluster:
    certificate-authority-data: ${ca}
    server: ${server}
contexts:
- name: default-context
  context:
    cluster: default-cluster
    namespace: default
    user: default-user
current-context: default-context
users:
- name: default-user
  user:
    token: ${token}
"