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Lab 10: Configuring kubectl for Remote Access

Info

This is a fork of the original "Kubernetes the hard way" originally written by Kelsey Hightower (GitHub: kelseyhightower). Unlike the original, which bases itself on Debian-like distributions for the ARM64 architecture, this fork targets Enterprise Linux distributions such as Rocky Linux, which runs on x86_64 architecture.

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.

Based on the /etc/hosts DNS entry from an earlier lab, you should be able to pingserver.kubernetes.local.

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

{
  "major": "1",
  "minor": "32",
  "gitVersion": "v1.32.0",
  "gitCommit": "70d3cc986aa8221cd1dfb1121852688902d3bf53",
  "gitTreeState": "clean",
  "buildDate": "2024-12-11T17:59:15Z",
  "goVersion": "go1.23.3",
  "compiler": "gc",
  "platform": "linux/amd64"
}

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 command line 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: v1.32.0
Kustomize Version: v5.5.0
Server Version: v1.32.0

List the nodes in the remote Kubernetes cluster:

kubectl get nodes

NAME     STATUS   ROLES    AGE   VERSION
node-0   Ready    <none>   30m   v1.31.2
node-1   Ready    <none>   35m   v1.31.2

Next: Provisioning Pod Network Routes

Author: Wale Soyinka

Contributors: Steven Spencer