Simple Watchdog script

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 I will give an example of a simple script for restarting services if they are not running and sending a notification by email:



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#!/bin/bash
SERVICES="ssh apache2 zabbix-server zabbix-agent mysql smbd nmbd asterisk"
DATE=$(date '+%d-%m-%Y %H:%M:%S')
 
for SERVICE in ${SERVICES}
 do
   service $SERVICE status 2>&1>/dev/null
    if [ $? -ne 0 ];
      then
        service $SERVICE stop
        sleep 3
        service $SERVICE start
        echo -e "Starting $SERVICE"
        (echo "Subject:Restarting $SERVICE"; echo "$DATE $SERVICE is not running on $HOSTNAME! Restarting!";) | sendmail test@ixnfo.com
      else
        echo -e "$SERVICE OK"
    fi
done

In the script, specify the email on which you want to receive notifications, and in the “SERVICES” list of services through the space that you want to check.
I first stopped the service in order to surely stop all possible processes, paused for 3 seconds and then started, because with the restart command, some highly loaded services could not start correctly and hang with the status “active (exited)”.

To make the script automatically run for example every 10 minutes, add a line to /etc/crontab:

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*/10 * * * * root /dir/watchdog.sh > /dev/null 2>&1
Continue reading Simple Watchdog script

Restarting a Linux Server via Web Browser (PHP)

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 After opening and reading every result on Google, I figured it's time to make my own thread somewhere.

I'm trying to setup a means of rebooting/doing other system functions through a web interface powered by HTML (for the buttons/text) and PHP (for the execution of the aforementioned functions).

I'm unable to get this to work. I've read that I need to add the web user to the sudoers file, and I've tried. I'm running Nginx on my server, how do I add the user to the sudoers in my case?

Also, I'm aware of the security risks, and would prefer not to be advised of them, thanks.

The following is what I have so far:

HTML:

HTML
<body>

<h3>Restart</h3>
<p>
<form action="restart.php" method="get">
  <input type="submit" value="Press me.">
</form>
</p>

</body>

PHP:

PHP
<?php
echo "This is a test";
echo "<br>";
echo "<br>";
echo shell_exec('ifconfig');
echo "<br>";
echo "<br>";
echo "Restarting server...";
exec ('/usr/bin/sudo /etc/init.d/portmap restart');
shell_exec("/sbin/reboot");
exec("/sbin/reboot");
system("/sbin/reboot");
?>

Mind you that here, I only have so many things attempting to execute, so that I make sure I hit the target when one of them works, if that makes sense. The IFConfig is just a test to make sure that it's actually able to execute.

Sudoers:

Text
# User privilege specification
root    ALL=(ALL:ALL) ALL
www-data reboot = NOPASSWD: /sbin/reboot

Hope help comes. Thanks.

---------------------------------------------

EDIT - I got a response from another location that fixed my problem. In the case that someone is dealing with a similar problem, here's the solution that helped me.

Text
You can do this either by editing your sudoers file :

Sudoers:
www-data ALL=(root) NOPASSWD: /sbin/reboot 

The first ALL is for the hostname if you're hostname is not 'reboot' I advise you to keep ALL as it will work in any hostname. That's why I don't seem to work on your server


restart.php:
exec('sudo /sbin/reboot');
Continue reading Restarting a Linux Server via Web Browser (PHP)