From 8a16a2233edc1af87c2be054a9931d8529e027e8 Mon Sep 17 00:00:00 2001
From: deajan <ozy@badministrateur.com>
Date: Mon, 18 Nov 2013 22:44:20 +0100
Subject: [PATCH] Added monitor mode

---
 CHANGELOG.md |  2 ++
 README.md    |  5 +++++
 osync.sh     | 39 ++++++++++++++++++++++++++++++++++++---
 3 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0479da9..6b191b7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@ SHORT FUTURE IMPROVEMENTS (post v1.0)
 - Sync and delete propagation function merge (master and slave functions are the same, reduces code size and maintain effort)
 - Tree function merge (current and after tree functions are the same except for output filename and logging, reduces code size and maintain effort)
 - Tree functions execute piped commands (grep, awk) on master when launched on remote slave which can cause more bandwith usage
+- Daemonize osync --on-changes mode
 
 FAR FUTURE IMPROVEMENTS
 -----------------------
@@ -20,6 +21,7 @@ KNOWN ISSUES
 RECENT CHANGES
 --------------
 
+- Added monitor mode, which will launch a sync task upon file operations on master replica
 - Changed conf file default format for ssh uri (old format is still compatible)
 - Added ssh uri support for slave replicas
 - Improved execution hooks logs
diff --git a/README.md b/README.md
index 417994b..2015548 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,7 @@ Bitpocked inspired me to write my own implementation of a two way sync script, i
 - Soft deletition and multiple backups handling
 - Before / after command execution
 - Time control
+- Sync on changes
 
 Osync uses a master / slave sync schema. It can sync local and local or local and remote directories. By definition, master replica should always be a local directory on the system osync runs on.
 Also, osync uses pidlocks to prevent multiple concurrent sync processes on/to the same master / slave replica. Be sure a sync process is finished before launching next one.
@@ -72,6 +73,10 @@ Once you're confident about your fist runs, you may add osync as cron task with:
 
 	$ ./osync.sh /path/to/your.conf --silent
 
+Additionnaly, you may run osync in monitor mode, which means it will perform a sync upon file operations on master replica.
+
+	$ ./osync.sh /path/to/your.conf --on-changes
+
 You may then find osync output in /var/log/osync-*.log (or current directory if /var/log is not writable).
 
 ## Author
diff --git a/osync.sh b/osync.sh
index 68c5d7d..96b395b 100755
--- a/osync.sh
+++ b/osync.sh
@@ -1466,8 +1466,13 @@ function Init
         set -o pipefail
         set -o errtrace
 
-        trap TrapStop SIGINT SIGKILL SIGHUP SIGTERM SIGQUIT
-	trap TrapQuit EXIT
+	# Do not use exit and quit traps if osync runs in monitor mode
+	if [ $sync_on_changes -eq 0 ]
+	then
+	        trap TrapStop SIGINT SIGKILL SIGHUP SIGTERM SIGQUIT
+		trap TrapQuit EXIT
+	fi
+
         if [ "$DEBUG" == "yes" ]
         then
                 trap 'TrapError ${LINENO} $?' ERR
@@ -1667,6 +1672,7 @@ function Usage
 	echo "--verbose: adds command outputs"
 	echo "--no-maxtime: disables any soft and hard execution time checks"
 	echo "--force-unlock: will override any existing active or dead locks on master and slave replica"
+	echo "--on-changes: will launch a sync as soon as there is some file activity on master replica."
 	echo ""
 	echo "Quick usage only:"
 	echo "--master= : Specify master replica path. Will contain state and backup directory."
@@ -1675,6 +1681,22 @@ function Usage
 	exit 128
 }
 
+function SyncOnChanges
+{
+	if ! type -p inotifywait > /dev/null 2>&1
+	then
+        	LogError "No inotifywait command found."
+        	exit 1
+	fi
+
+	while true
+	do
+        	inotifywait --exclude $OSYNC_DIR $RSYNC_EXCLUDE -qq -r -e create -e modify -e delete -e move -e attrib "$MASTER_SYNC_DIR/" 
+        	$osync_cmd "$ConfigFile"
+	done
+
+}
+
 # Comand line argument flags
 dryrun=0
 silent=0
@@ -1691,6 +1713,8 @@ soft_alert_total=0
 error_alert=0
 soft_stop=0
 quick_sync=0
+sync_on_changes=0
+osync_cmd=$0
 
 if [ $# -eq 0 ]
 then
@@ -1731,6 +1755,9 @@ do
 		--rsakey=*)
 		SSH_RSA_PRIVATE_KEY=${i##*=}
 		;;
+		--on-changes)
+		sync_on_changes=1
+		;;
 	esac
 done
 
@@ -1746,9 +1773,15 @@ then
 		SOFT_DELETE_DAYS=30
 		RESUME_TRY=1
 	else
-		LoadConfigFile "$1"
+		ConfigFile="$1"
+		LoadConfigFile "$ConfigFile"
 	fi
 	Init
+	if [ $sync_on_changes -eq 1 ]
+	then
+		SyncOnChanges
+		exit
+	fi
 	DATE=$(date)
 	Log "-------------------------------------------------------------"
 	Log "$DRY_WARNING $DATE - Osync v$OSYNC_VERSION script begin."