Flip between versions of the Kubernetes CLI easily

kubectl-select

#!/bin/bash

# Simple script to help configuring which kubectl CLI to use when you
# have a need to keep multiple versions and switch between them.

# Install and notes:
# 1. put this in /usr/local/bin and chmod +x
# 2. keep all the versions of kubectl in the /Applications directory
# 3. name kubectl executables with corresponding version - e.g. /Applications/kubectl-1.19.0

# Ref - for where to get versions of kubectl
# https://kubernetes.io/docs/tasks/tools/install-kubectl/

prompt="Please select an kubectl version:"
options=( $(ls /Applications/kubectl* | xargs -0) )

PS3="$prompt "
select opt in "${options[@]}" "Quit" ; do 
    if (( REPLY == 1 + ${#options[@]} )) ; then
        exit

    elif (( REPLY > 0 && REPLY <= ${#options[@]} )) ; then
        echo  "You picked $REPLY"
        break

    else
        echo "Invalid option. Try another one."
    fi
done    

echo "Switching kubectl to version at $opt"

ln -sf $opt /usr/local/bin/kubectl

kubectl version

if test -z $BASH_VERSION; then
    source <(kubectl completion bash)
    echo "Autocompletion ON (bash)"
elif test -z $ZSH_VERSION; then
    source <(kubectl completion zsh)
    echo "Autocompletion ON (zsh)"
fi