Rancher Suite K8S Adventure - Chapter 006 - Kubectl

Rancher Suite K8S Adventure - Chapter 006 - Kubectl

A travelogue of converting from OpenStack to Suse's Rancher Suite for K8S including RKE2, Harvester, kubectl, helm.

Kubectl version 1.24 is installed on all members of the Rancher RKE2 cluster and on my Ubuntu experimentation box using Ansible.

https://kubernetes.io/docs/reference/kubectl/

https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands

https://kubernetes.io/docs/tasks/tools/install-kubectl-linux/

The exact version of the Ubuntu package I'm installing is 1.24.10-00 as seen at

https://packages.cloud.google.com/apt/dists/kubernetes-xenial/main/binary-amd64/Packages

And I'm doing an "apt hold" on it to make sure its not accidentally upgraded.

Here is a link to the gitlab repo directory for the Ansible kubectl role:

https://gitlab.com/SpringCitySolutionsLLC/ansible/-/tree/master/roles/kubectl

If you look at the Ansible task named packages.yml, the task installs some boring required packages first, then deletes the Google K8S repo key if its too old, then downloads a new copy of the Google K8S repo key if its not already present, add the local copy of the Google K8S repo key to apt's list of known good keys, installs the sources.list file for Google's K8S repo, does an apt-get update, takes kubectl out of "hold" state, installs the latest package for kubectl version 1.24, finally places kubectl back on "hold" state so its not magically upgraded to the latest version (1.26 or 1.27 or something by now).  Glad I don't have to do that manually by hand on every machine, LOL!

Ansible makes life easy, all I need to do to have the most recent kubectl installed on a Ubuntu system is add "- kubectl" to that system's playbook, then run "ansible-playbook --tags kubectl playbooks/someHostname.yml" and like magic in seconds it'll work.

As of the time this blog was written, "kubectl version --short" looks like this:

vince@ubuntu:~$ kubectl version --short
Flag --short has been deprecated, and will be removed in the future. The --short output will become the default.
Client Version: v1.24.10
Kustomize Version: v4.5.4
The connection to the server localhost:8080 was refused - did you specify the right host or port?

vince@ubuntu:~$ 

Note that the last step is you probably want to enable bash autocompletion for kubectl in .bashrc for whatever username you log in as. My .bashrc file has a line like this:

source <(kubectl completion bash)

Mine is actually wrapped by some if $HOSTNAME lines, but whatever.

After you do this and log back in, you can type "kubectl" and hit tab a couple times and autocompletion will work. Pretty cool!