#!/bin/bash
#
# Nagios plugin to check Git repository status
#
# Author : Benjamin Renard <brenard@easter-eggs.com>
# Date : Wed, 14 Mar 2012 14:45:55 +0000
# Source : http://git.zionetrix.net/check_git_config
#

GIT_ROOT=/srv/common
GIT_REMOTE=origin
DEBUG=0
CHECK_REMOTE=0
HIDE_CHANGES=0
FULL_DIFF=0

function usage() {
	echo "Usage : $0 -g [directory] [-c|-r remote] [-d]
	-g [directory]	Specify Git root directory (default : $GIT_ROOT)
	-c		Check Git remote state
	-r [remote]	Specify Git remote to check (default : $GIT_REMOTE)
	-H		Hide detected changes
	-F		Show full diff in case of changes detected (default: short)
	-d		Enable debug mode"
}

while getopts "g:r:cdFHh-:" OPTION
do
	case "$OPTION" in
		c)
			CHECK_REMOTE=1
		;;
		g)
			GIT_ROOT="${OPTARG}"
		;;
		r)
			CHECK_REMOTE=1
			GIT_REMOTE="${OPTARG}"
		;;
		d)
			DEBUG=1
		;;
		H)
			HIDE_CHANGES=1
		;;
		F)
			FULL_DIFF=1
		;;
		h)
			usage
			exit 0
		;;
		*)
			echo "Invalid parameter -$OPTION"
			echo
			usage
			exit 1
		;;
	esac
done

[ ! -d "$GIT_ROOT" ] && echo "UNKNOWN : Git root directory does not exists !" && exit 3
[ ! -d "$GIT_ROOT/.git" ] && echo "UNKNOWN : Git root directory seem to not being a git repository." && exit 3

cd $GIT_ROOT

STATUS=$( git status -s 2>&1 )
res=$?
[ $DEBUG -eq 1 ] && echo -e "Status (return $res): $STATUS"

if [ $res -ne 0 ]
then
	echo "UNKNOWN : Fail to retreive git status (return code : $res)"
	echo -e "$STATUS"
	exit 3
elif [ -n "$STATUS" ]
then
	echo "WARNING : Git config repo on $( hostname ) not clean"
	if [ $FULL_DIFF -eq 1 ]
	then
		git diff
	elif [ $HIDE_CHANGES -ne 1 ]
	then
		echo -e "$STATUS"
	fi
	exit 1
elif [ $CHECK_REMOTE -eq 1 ]
then
	# Check remote exists
	[ $DEBUG -eq 1 ] && echo -n "Check remote '$GIT_REMOTE' exist : "
	git remote show "$GIT_REMOTE" > /dev/null 2>&1
	res=$?
	[ $DEBUG -eq 1 ] && echo "done. (Return $res)"

	if [ $res -ne 0 ]
	then
		echo "UNKNOWN : Unkown remote '$GIT_REMOTE'"
		exit 3
	fi

	[ $DEBUG -eq 1 ] && echo -n "Fecth : "
	git fetch "$GIT_REMOTE" > /dev/null 2>&1
	res=$?
	[ $DEBUG -eq 1 ] && echo "done. (Return $res)"

	if [ $res -ne 0 ]
	then
		echo "UNKNOWN : Error fetching remote"
		exit 3
	fi

	HEAD="$( git show HEAD|grep ^commit )"
	[ $DEBUG -eq 1 ] && echo "Local : $HEAD"

	ORIGIN="$( git show origin|grep ^commit )"
	[ $DEBUG -eq 1 ] && echo "Remote : $ORIGIN"
	
	if [ "$HEAD" != "$ORIGIN" ]
	then
		echo "CRITICAL : Git config not uptodate"
		exit 2
	fi
fi
echo "OK"
exit 0