kubernetes-the-hard-way/docs/10-configuring-kubectl.md

Configuring kubectl for Remote Access

In this lab you will generate a kubeconfig file for the kubectl command line utility based on the admin user credentials.

Run the commands in this lab from the jumpbox machine.

The Admin Kubernetes Configuration File

Each kubeconfig requires a Kubernetes API Server to connect to.

You should be able to ping server.kubernetes.local based on the /etc/hosts DNS entry from a previous lap.

curl -k --cacert ca.crt \
  https://server.kubernetes.local:6443/version

{
  "major": "1",
  "minor": "28",
  "gitVersion": "v1.28.3",
  "gitCommit": "a8a1abc25cad87333840cd7d54be2efaf31a3177",
  "gitTreeState": "clean",
  "buildDate": "2023-10-18T11:33:18Z",
  "goVersion": "go1.20.10",
  "compiler": "gc",
  "platform": "linux/arm64"
}

Generate a kubeconfig file suitable for authenticating as the admin user:

{
  kubectl config set-cluster kubernetes-the-hard-way \
    --certificate-authority=ca.crt \
    --embed-certs=true \
    --server=https://server.kubernetes.local:6443

  kubectl config set-credentials admin \
    --client-certificate=admin.crt \
    --client-key=admin.key

  kubectl config set-context kubernetes-the-hard-way \
    --cluster=kubernetes-the-hard-way \
    --user=admin

  kubectl config use-context kubernetes-the-hard-way
}

The results of running the command above should create a kubeconfig file in the default location ~/.kube/config used by the kubectl commandline tool. This also means you can run the kubectl command without specifying a config.

Verification

Check the version of the remote Kubernetes cluster:

kubectl version

Client Version: v1.28.3
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Server Version: v1.28.3

List the nodes in the remote Kubernetes cluster:

kubectl get nodes

NAME     STATUS   ROLES    AGE   VERSION
node-0   Ready    <none>   30m   v1.28.3
node-1   Ready    <none>   35m   v1.28.3

Next: Provisioning Pod Network Routes