Client-Go

import (
  "k8s.io/client-go/rest"
)
...

rest.InClusterConfig()

$ kubectl create serviceaccount incluster-sa -n kube-public

$ kubectl apply -f - <<EOF
apiVersion: v1
kind: Secret
metadata:
  name: incluster-sa-token
  namespace: kube-public
  annotations:
    kubernetes.io/service-account.name: incluster-sa
type: kubernetes.io/service-account-token
EOF

$ kubectl create clusterrolebinding incluster-binding --clusterrole=cluster-admin --serviceaccount=kube-public:incluster-sa

$ sudo mkdir -p /var/run/secrets/kubernetes.io/serviceaccount
$ kubectl get secret incluster-sa-token -n kube-public -o jsonpath='{.data.ca\.crt}' | base64 --decode | sudo tee /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
$ kubectl get secret incluster-sa-token -n kube-public -o jsonpath='{.data.token}' | base64 --decode | sudo tee /var/run/secrets/kubernetes.io/serviceaccount/token

$ CLUSTER="$(kubectl config view --raw=true -o jsonpath="{.contexts[?(@.name==\"$(kubectl config current-context)\")].context.cluster}")"
$ export KUBERNETES_SERVICE_HOST=$(kubectl config view --raw=true -o jsonpath="{.clusters[?(@.name==\"$CLUSTER\")].cluster.server}" |  awk -F/ '{print $3}' |  awk -F: '{print $1}')
$ export KUBERNETES_SERVICE_PORT=$(kubectl config view --raw=true -o jsonpath="{.clusters[?(@.name==\"$CLUSTER\")].cluster.server}" |  awk -F/ '{print $3}' |  awk -F: '{print $2}')