kubectl-nodetypes

#!/usr/bin/env bash

##
## This script can be used as a kubectl plugin. After saving this script somewhere in your PATH environment variable
## and ensuring that it is executable you can use it as a kubectl plugin.
##
##  bash $ kubectl nodetypes
##  bash $ kubectl nodetypes 2>/dev/null
## 
## 2022.08.12
##
## Check out:
##   https://kubernetes.io/docs/tasks/extend-kubectl/kubectl-plugins/
##   https://kubernetes.io/docs/reference/kubectl/jsonpath/  (examples at the bottom of the page!)
##
set -euo pipefail
IFS=$'\n\t'

## http://redsymbol.net/articles/unofficial-bash-strict-mode/ 
## explains why we need above lines

tmpdir=$(mktemp -d /tmp/tmp.VL."$(basename "$0")".XXXXXXXXXX)
cleanup() {
  rm -rf "${tmpdir}"
}
trap cleanup EXIT QUIT INT

podnodes() {
  local NS
  NS="${1:-default}"

  >&2 printf "%s | %s\n" "Node" "Pod"
  kubectl --namespace "${NS}" get -o=jsonpath='{range .items[*]}{.spec.nodeName}{" | "}{.metadata.name}{"\n"}{end}' pods
}

nodetypes() {
  local NS
  NS="${1:-default}"

  >&2 printf "%s | %s\n" "Node" "InstanceType"
  kubectl --namespace "${NS}" get -o=jsonpath='{range .items[*]}{.metadata.name}{" | "}{.metadata.labels.beta\.kubernetes\.io\/instance-type}{"\n"}{end}' nodes
}

podnodes "${1:-default}"
printf "%s\n" "----------------------------------------------------------" >&2
nodetypes "${1:-default}"