yum.sh: yum update monitor (#1273)

Signed-off-by: Slawomir Gonet <slawek@otwiera.cz>

text_collector_examples/yum.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+#
+# Description: Expose metrics from yum updates.
+#
+# Author: Slawomir Gonet <slawek@otwiera.cz>
+# 
+# Based on apt.sh by Ben Kochie <superq@gmail.com>
+
+upgrades=$(/usr/bin/yum -q check-updates | awk 'BEGIN { mute=1 } /Obsoleting Packages/ { mute=0 } mute { print }' | egrep '^\w+\.\w+' | awk '{print $3}' | sort | uniq -c | awk '{print "yum_upgrades_pending{origin=\""$2"\"} "$1}')
+
+echo '# HELP yum_upgrades_pending Yum package pending updates by origin.'
+echo '# TYPE yum_upgrades_pending gauge'
+if [[ -n "${upgrades}" ]] ; then
+  echo "${upgrades}"
+else
+  echo 'yum_upgrades_pending{origin=""} 0'
+fi
+