check_kubernetes_api.sh

#!/bin/bash

#########################################################
# 	./check_kubernetes.sh 				#
#							#
# 	Nagios check script for kubernetes cluster	#
#	This is a super simple check, with plenty	#
#	of room for improvements :)			#
# 	Author:  Justin Miller				#
# 	Website: https://github.com/colebrooke		#
# 							#
#########################################################

function usage {
cat <<EOF
Usage ./check_kubernetes [-t <TARGETSERVER> -c <CREDENTIALSFILE>] [-k <KUBE_CONFIG>]

Options:
  -t <TARGETSERVER>	# Required, the endpoint for your Kubernetes API
  -c <CREDENTIALSFILE>	# Required, credentials for your Kubernetes API, in the format outlined below

Credentials file format:
machine yourEndPointOrTarget login yourUserNameHere password YOURPASSWORDHERE

EOF

exit 2
}

# Comment out if you have SSL enabled on your K8 API
SSL="--insecure"

while getopts ":t:c:hk:" OPTIONS; do
	case "${OPTIONS}" in
		t) TARGET=${OPTARG} ;;
		c) CREDENTIALS_FILE="--netrc-file ${OPTARG}" ;;
		h) usage ;;
		k) KUBE_CONFIG="--kubeconfig ${OPTARG}" ;;
		*) usage ;;
	esac
done

if [ -z $TARGET ]; then 
	type kubectl >/dev/null 2>&1 || { echo >&2 "CRITICAL: The kubectl utility is required for this script to run if no API endpoint target is specified"; exit 3; }
	kubectl $KUBE_CONFIG proxy >/dev/null 2>&1 &
	PROXY_PID=$!
	sleep 1
	TARGET="http://127.0.0.1:8001"
fi

HEALTH=$(curl -sS $SSL $CREDENTIALS_FILE $TARGET/healthz)
BSC_HEALTH=$(curl -sS $SSL $CREDENTIALS_FILE $TARGET/healthz/poststarthook/bootstrap-controller)
EXT_HEALTH=$(curl -sS $SSL $CREDENTIALS_FILE $TARGET/healthz/poststarthook/extensions/third-party-resources)
BSR_HEALTH=$(curl -sS $SSL $CREDENTIALS_FILE $TARGET/healthz/poststarthook/rbac/bootstrap-roles)

kill -15 $PROXY_PID

case "$HEALTH $BSC_HEALTH $BSR_HEALTH" in 
	"ok ok ok") echo "OK - Kubernetes API status is OK" && exit 0;;
	*) 
		echo "WARNING - Kubernetes API status is not OK!"
		echo "/healthz - $HEALTH"
		echo "/healthz/poststarthook/bootstrap-controller - $BSC_HEALTH"
		echo "/healthz/poststarthook/extensions/third-party-resources - $EXT_HEALTH"
		echo "/healthz/poststarthook/rbac/bootstrap-roles - $BSR_HEALTH"
		exit 1
	;;
esac