From 1c34e9715fc5123f756d9a10b2b820c17a01da5c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yavuz=20Ayd=C4=B1n?= <ya@snel.com>
Date: Thu, 7 Jan 2021 16:45:53 +0100
Subject: [PATCH] first commit

---
 check_reboot-required | 69 +++++++++++++++++++++++++++----------------
 1 file changed, 43 insertions(+), 26 deletions(-)

diff --git a/check_reboot-required b/check_reboot-required
index a78aa8f..266c3dc 100644
--- a/check_reboot-required
+++ b/check_reboot-required
@@ -22,7 +22,7 @@
 # Script: check_reboot-required                                                              #
 # License: This file is licensed under the GPLv3 License                                     #
 # Purpose: Check if reboot is required                                                       #
-# Tested on: Proxmox 6, CentOS 6/7/8, Debian 8/9/10 and Ubuntu 16.04/18.04/20.04             #
+# Tested on: Proxmox 6, CentOS 6/7/8, Debian 7/8/9/10 and Ubuntu 16.04/18.04/20.04           #
 #                                                                                            #
 ##############################################################################################
 #                                                                                            #
@@ -36,17 +36,27 @@
 
 APPNAME=`basename $0`
 
-OK=0
-WARNING=1
-CRITICAL=2
-UNKNOWN=3
+# Defining standard messages and exit error levels
+# https://nagios-plugins.org/doc/guidelines.html
+OK_EXIT_CODE=0
+WARNING_EXIT_CODE=1
+CRITICAL_EXIT_CODE=2
+UNKNOWN_EXIT_CODE=3
+OK_MSG="OK"
+WARNING_MSG="Warning"
+CRITICAL_MSG="Critical"
+UNKNOWN_MSG="Unknown"
+
+# Using Unknown as default
+EXIT_CODE=$UNKNOWN_EXIT_CODE
+EXIT_MSG=$UNKNOWN_MSG
 
 warn_only="false"
 
 which lsb_release 2>/dev/null >/dev/null
 if [ $? -ne 0 ]; then
   echo "lsb_release is missing"
-  exit ${UNKNOWN}
+  exit ${UNKNOWN_EXIT_CODE}
 fi
 
 function usage() {
@@ -70,7 +80,7 @@ case $1 in
     ;;
   -h|--help)
     usage
-    exit 0
+    exit ${OK_EXIT_CODE}
     ;;
 esac
 
@@ -82,20 +92,22 @@ function check_debian() {
       packages=""
     fi
     if [ -z "${packages}" ]; then
+      EXIT_MSG_BODY="System reboot is required"
       if [ "${warn_only}" == "true" ]; then
-        echo "System reboot is required"
-        exit ${WARNING}
+        EXIT_MSG=${WARNING_MSG}
+        EXIT_CODE=${WARNING_EXIT_CODE}
       else
-        echo "System reboot is required"
-        exit ${CRITICAL}
+        EXIT_MSG=${CRITICAL_MSG}
+        EXIT_CODE=${CRITICAL_EXIT_CODE}
       fi
     else
+      EXIT_MSG_BODY="System reboot is required by: ${packages}"
       if [ "${warn_only}" == "true" ]; then
-        echo "System reboot is required by: ${packages}"
-        exit ${WARNING}
+        EXIT_MSG=${WARNING_MSG}
+        EXIT_CODE=${WARNING_EXIT_CODE}
       else
-        echo "System reboot is required by: ${packages}"
-        exit ${CRITICAL}
+        EXIT_MSG=${CRITICAL_MSG}
+        EXIT_CODE=${CRITICAL_EXIT_CODE}
       fi
     fi
   else
@@ -112,14 +124,16 @@ function check_redhat() {
 
   output=$(needs-restarting -r | xargs)
   if [ $? -eq 0 ]; then
-    echo "${output}"
-    exit ${OK}
+    echo "No reboot required: ${output}"
+    exit ${OK_EXIT_CODE}
   elif [ $? -eq 1 ]; then
-    echo "${output}"
+    EXIT_MSG_BODY="${output}"
     if [ "${warn_only}" == "true" ]; then
-      exit ${WARNING}
+      EXIT_MSG=${WARNING_MSG}
+      EXIT_CODE=${WARNING_EXIT_CODE}
     else
-      exit ${CRITICAL}
+      EXIT_MSG=${CRITICAL_MSG}
+      EXIT_CODE=${CRITICAL_EXIT_CODE}
     fi
   fi
 }
@@ -128,15 +142,17 @@ function check_running_kernel() {
   newest_installed_kernel=`ls -t /boot/vmlinuz-* | sed "s/\/boot\/vmlinuz-//g" | head -n1`
   running_kernel=`uname -r`
   if [[ $newest_installed_kernel != $running_kernel ]]; then
-    echo "System reboot is required by: newer kernel (${newest_installed_kernel}) is available, running kernel is ${running_kernel}"
+    EXIT_MSG_BODY="System reboot is required by: newer kernel (${newest_installed_kernel}) is available, running kernel is ${running_kernel}"
     if [ "${warn_only}" == "true" ]; then
-      exit ${WARNING}
+      EXIT_MSG=${WARNING_MSG}
+      EXIT_CODE=${WARNING_EXIT_CODE}
     else
-      exit ${CRITICAL}
+      EXIT_MSG=${CRITICAL_MSG}
+      EXIT_CODE=${CRITICAL_EXIT_CODE}
     fi
   else
     echo "No reboot required"
-    exit ${OK}
+    exit ${OK_EXIT_CODE}
   fi
 }
 
@@ -154,5 +170,6 @@ case "${distro}" in
     ;;
 esac
 
-# Never reached
-exit ${UNKNOWN}
+# Echo message and exit
+echo "${EXIT_MSG}: ${EXIT_MSG_BODY}"
+exit $EXIT_CODE