coredns/vendor/k8s.io/client-go/examples/out-of-cluster-client-configuration

Authenticating outside the cluster

This example shows you how to configure a client with client-go to authenticate to the Kubernetes API from an application running outside the Kubernetes cluster.

You can use your kubeconfig file that contains the context information of your cluster to initialize a client. The kubeconfig file is also used by the kubectl command to authenticate to the clusters.

Running this example

Make sure your kubectl is configured and pointed to a cluster. Run kubectl get nodes to confirm.

Run this application with:

cd out-of-cluster-client-configuration
go build -o app .
./app

Running this application will use the kubeconfig file and then authenticate to the cluster, and print the number of nodes in the cluster every 10 seconds:

$ ./app
There are 3 pods in the cluster
There are 3 pods in the cluster
There are 3 pods in the cluster
...

Press Ctrl+C to quit this application.

Note: You can use the -kubeconfig option to use a different config file. By default this program picks up the default file used by kubectl (when KUBECONFIG environment variable is not set).