rsyncclientd

#!/bin/bash
## Script to start rsync client as a daemon
## Copyright 2014, Jorge Fonseca - http://jorge.fonseca.ec

## Licensed under the Apache License, Version 2.0 (the "License");
## you may not use this file except in compliance with the License.
## You may obtain a copy of the License at

##    http://www.apache.org/licenses/LICENSE-2.0

## Unless required by applicable law or agreed to in writing, software
## distributed under the License is distributed on an "AS IS" BASIS,
## WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
## See the License for the specific language governing permissions and
## limitations under the License.

## Check if any argument has been recieved
if [ "$#" -eq 0 ]; then
	echo "USAGE: $0 <CONFIGURATION FILE>"
	echo ""
	echo "	This script can execute a rsync client instance as a system service."
	echo "	Configuration is defined in the file given as argument"
	exit 2
else
	CONFIGFILE=$1
fi
# Check for depencies
if [ ! `which which` ]; then
	echo "FATAL: \"which\" was not found in the system"
	exit 2
else
	REQUERIMENTS='rsync logger nc grep wc ps'
	for REQ in $REQUERIMENTS
	do
		REQCHECK=`which $REQ`
		if [ ! $REQCHECK ]; then
			echo "FATAL: \"$REQ\" was not found in the system"
			exit 2
		fi
	done
fi
## Check if the configuration file exist
if [ ! -s "$CONFIGFILE" ] || [ ! -r "$CONFIGFILE" ]; then
	"FATAL: cannot read $CONFIGFILE"
	exit 2
else
## Read the configuration file if exist
	. $CONFIGFILE
fi
## Check for necesary variables in the config file and exit if not exist
if [ "$HOST" = "" ]; then
## Exit if $HOST is not defined
	echo "FATAL: HOST not defined in $CONFIGFILE"
	exit 2
elif [ "$SOURCE" = "" ]; then
## Exit if $SOURCE is not defined
	echo "FATAL: SOURCE not defined in $CONFIGFILE"
	exit 2
elif [ "$DESTINATION" = "" ]; then
## Exit if $DESTINATION is not defined
	echo "FATAL: DESTINATION not defined in $CONFIGFILE"
	exit 2
elif [ "$SYNC_INTERVAL" = "" ]; then
## Exit if $SYNC_INTERVAL is not defined
	echo "FATAL: SYNC_INTERVAL not defined in $CONFIGFILE"
	exit 2
else
## Set generic tag for logging and define log file if set
	if [ $LOGFILE ]; then
		LOGGER_OPTIONS="-f $LOGFILE"
	fi
	LOG_TAG="rsyncclientd"
	LOGGER="logger $LOGGER_OPTIONS -st $LOG_TAG -- "
## Read optional variables in configuration filename and assign default values
	if [ "$WAIT_INTERVAL" = "" ]; then
		WAIT_INTERVAL="300"
	fi
	if [ "$OPTIONS" = "" ]; then
		OPTIONS="-rtvpogl  --delay-updates --delete-delay timeout=60"
	fi
## All configurations set, will start the rsync service
	$LOGGER "Starting RSYNC client with an interval of $SYNC_INTERVAL seconds"
fi
## Start the client
while true;
do
	$LOGGER "Trying to synchronize with RSYNC source $SOURCE on destination $DESTINATION..."
	INSTANCES=`ps faux|grep "rsync"|grep -w "$DESTINATION"|wc -l`
	if [ "$INSTANCES" -gt "1" ]; then
		$LOGGER "Seems like another instance of rsync is running on the same destination ($DESTINATION). script ending..."
		exit 1
	else
		if [ "$DEBUG" = "yes" ]; then
			SYNC_OUTPUT=`rsync $OPTIONS $HOST::$SOURCE $DESTINATION`
			SYNC_STATUS=$?
			$LOGGER "\n $SYNC_OUTPUT"
		else
			SYNC_OUTPUT=`rsync $OPTIONS -q $HOST::$SOURCE $DESTINATION`
			SYNC_STATUS=$?
		fi
## Write the result of the process to log file
		if [ "$SYNC_STATUS" -ne "0" ]; then
			$LOGGER "ERROR: RSYNC fail with status code $SYNC_STATUS"
			$LOGGER "Retrying in $WAIT_INTERVAL seconds..."
			sleep $WAIT_INTERVAL
			continue
		else
			$LOGGER "SUCCESS: synchronized with $HOST"
			$LOGGER "Sleeping for $SYNC_INTERVAL seconds..."
			sleep $SYNC_INTERVAL || break
		fi
	fi
done
exit 0