I can’t be the only one that has this issue and yet I’ve not been able to find any existing solutions.

At work I have to deal with multiple flavours and versions of Kubernetes. Until very recently stretching all the way from 1.12 up to 1.20. I found it a pain in the arse trying to ensure I was using the correct kubectl version; And helm, but that’s another story and fortunately less of an issue now.

kubectl does seem to be very compatible across differing versions, but I was still keeping different named binaries that looked like this:

ls bin/
[...]
kubectlv1-12
kubectlv1-16
kubectlv1-17
kubectlv1-19
kubectlv1-20

I decided to write a very simple shell function to switch to the correct version:

function kubeset {
	if ! which kubectl | grep -q kubectl
	then
		version=$(curl -L -s https://dl.k8s.io/release/stable.txt)
		minor=$(echo $version | sed -E 's/(v[0-9]+)\.([0-9]+)\..*/\1-\2/')
		curl -L "https://dl.k8s.io/release/$version/bin/darwin/arm64/kubectl" -o ~/bin/kubectl$minor
		chmod +x ~/bin/kubectl$minor
		rm -f ~/bin/kubectl && ln -s ~/bin/kubectl$minor ~/bin/kubectl
	fi
	version=$(kubectl version | grep Server | sed -E 's/.*(v[0-9]+)\.([0-9]+)\.([0-9]+).*/\1\.\2\.\3/')
	if [ $version ]
	then
		minor=$(echo $version | sed -E 's/(v[0-9]+)\.([0-9]+)\..*/\1-\2/')
		if test -f ~/bin/kubectl$minor
		then
			echo "Setting kubectl to $minor"
		else
			echo "Downloading kubectl $version and setting to that"
			curl -L https://dl.k8s.io/release/$version/bin/darwin/arm64/kubectl -o ~/bin/kubectl$minor
			chmod +x ~/bin/kubectl$minor
		fi
		rm ~/bin/kubectl && ln -s ~/bin/kubectl$minor ~/bin/kubectl
	fi
}

(I don’t care about patch version compatibility, just minor version)

It does require that there is an initial version of `kubectl` available. I guess it could be adjusted to handle that case, but if you're not careful you end up taking something [simple and elegant](https://github.com/ahmetb/kubectx/blob/master/kubectx) and [ending up with this](https://github.com/ahmetb/kubectx/tree/master/cmd/kubectx); Although snark aside this would be nice as a hook/extension to `kubectx`

.

Thankfully we’ve now torn down the 1.12 cluster (because it’s easier to tear down and re-write everything than upgrade K8s; more snark) so I have less versions to deal with.

[EDIT: 2021-03-30] This is actually more useful than I realised. Sometimes kubectx doesn’t work so well with mismatched kubectl versions. But this kubeset thing does the trick. Nice.

[EDIT: 2025-01-30] Had reason to re-visit this. Updated to handle no initial install of kubectl, Apple Silicon, latest download links, and to make it a bit more clever.