Bash Script To Restart Linux Server Services

Here’s the command line code to create the file in nano:

sudo nano /opt/launch-crashed-services.sh

Here is the bash script.

#!/bin/bash

service mysql status | grep 'active (running)' > /dev/null 2>&1
if [ $? != 0 ]
then
sudo service mysql restart > /dev/null
fi

service nginx status | grep 'active (running)' > /dev/null 2>&1
if [ $? != 0 ]
then
sudo service nginx restart > /dev/null
fi

service php7.2-fpm status | grep 'active (running)' > /dev/null 2>&1
if [ $? != 0 ]
then
sudo service php7.2-fpm restart > /dev/null
fi

Or you can use systemctl instead

#!/bin/bash

systemctl status mysql | grep 'active (running)' > /dev/null 2>&1
if [ $? != 0 ]
then
sudo systemctl restart mysql> /dev/null
fi

systemctl status nginx | grep 'active (running)' > /dev/null 2>&1
if [ $? != 0 ]
then
sudo systemctl restart  nginx > /dev/null
fi

systemctl status php7.2-fpm| grep 'active (running)' > /dev/null 2>&1
if [ $? != 0 ]
then
sudo systemctl restart php7.2-fpm > /dev/null
fi

Change the service names to the ones you are running, e.g. “apache2” or whatever PHP version you are running. The script uses the service <name> status command to output the status of a particular service such as mysql. We then run this through grep looking for the phrase “active (running)”. If this is not found, we ask the system to restart the service. Save the file to /opt/launch-crashed-services.sh Then ensure that it is runnable from the command line using:

sudo chmod +x /opt/launch-crashed-services.sh

Scheduling Service Restarts Using Crontab

It would be a pain to have to SSH into our server every time a service crashes to run the script. Instead we can call the script directly from a crontab service and have it running as frequently as we need it to. Edit your root crontab list using:

sudo crontab -e

It’s important to use the root crontab using the command above and not to edit your own user profile crontab, otherwise, it will not work properly. Add the following line to the bottom of the root crontab list:

*/1 * * * * /opt/launch-crashed-services.sh > /dev/null 2>

This will run the script every minute but you can change that for whatever works for your server. Now if a critical service crashes, the server will attempt to restart it.