Hadoop Nagios check under-replicated blocks

check_under_replicated_blocks.sh

#! /bin/bash

function http { (exec 3<>/dev/tcp/$1/$2; echo -e "$3 $4 HTTP/1.0\r\n\r\n" >&3; cat <&3); }

URB=$(http localhost 50070 GET /dfshealth.jsp | grep Under-Replicated | sed -e 's/.*Under-Replicated//' -e 's/.*col3\"> //' -e 's/<.*//')
if [ $URB -gt 0 ]; then
	echo "WARNING - Under-Replicated Blocks is $URB"
	exit 1
fi

echo "OK - Under-Replicated Blocks is $URB"
exit 0