From c43bdff1a916b090505ac400240ed0cc485884d2 Mon Sep 17 00:00:00 2001
From: Daniel Berteaud <daniel@firewall-services.com>
Date: Mon, 21 Mar 2016 10:16:28 +0100
Subject: [PATCH] Use flock to make sure only one gluster command run at a time

---
 zabbix_scripts/check_gluster_sudo | 6 ++++++
 zabbix_scripts/disco_gluster_sudo | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/zabbix_scripts/check_gluster_sudo b/zabbix_scripts/check_gluster_sudo
index dd006f5..c123121 100644
--- a/zabbix_scripts/check_gluster_sudo
+++ b/zabbix_scripts/check_gluster_sudo
@@ -10,12 +10,16 @@ my $peer = undef;
 my $bricks = undef;
 
 my $gluster = which('gluster');
+my $lock = '/var/lock/gluster-zabbix.lock';
 
 unless($gluster){
   # Gluster is not installed, exit with an error
   die "gluster command not found";
 }
 
+# Get an exclusive lock
+open(LOCK, ">$lock") || die "Can't open $lock";
+flock(LOCK, 2);
 
 GetOptions(
   "what=s"   => \$what,
@@ -150,3 +154,5 @@ elsif ($what eq 'peer'){
   print $status;
 }
 
+close(LOCK);
+exit(0);
diff --git a/zabbix_scripts/disco_gluster_sudo b/zabbix_scripts/disco_gluster_sudo
index 73c3ee0..b07d91e 100644
--- a/zabbix_scripts/disco_gluster_sudo
+++ b/zabbix_scripts/disco_gluster_sudo
@@ -9,6 +9,7 @@ my $json;
 @{$json->{data}} = ();
 
 my $gluster = which('gluster');
+my $lock = '/var/lock/gluster-zabbix.lock';
 
 unless($gluster){
   # Gluster is not installed, just return an empty JSON object
@@ -16,6 +17,10 @@ unless($gluster){
   exit(0);
 }
 
+# Get an exclusive lock
+open(LOCK, ">$lock") || die "Can't open $lock";
+flock(LOCK, 2);
+
 my $what = 'volumes';
 GetOptions(
   "what=s" => \$what,
@@ -110,6 +115,7 @@ else{
   exit(1);
 }
 
+close(LOCK);
 print to_json($json);
 exit(0);