How to Troubleshoot Common Apache Issues on Linux Server?

I would recommend following these steps in case that you are having any problems with your Apache server and you are unsure about what the problem is:

• Check if Apache is running:

systemctl status apache2

If Apache is running you should see something like this:

● apache2.service - The Apache HTTP Server
   Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2019-11-19 09:37:46 UTC; 2 days ago
     Docs: https://httpd.apache.org/docs/2.4/

If Apache is not running then the output would look like this:

● apache2.service - The Apache HTTP Server
   Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
   Active: inactive (dead) since Fri 2019-11-22 08:41:01 UTC; 39s ago
     Docs: https://httpd.apache.org/docs/2.4/

• If Apache is not running you could start it with:

systemctl start apache2

Then check the status agian and make sure that Apache remains running.

• If Apache did not start after a reboot, you could enable it so that it starts after the next reboot:

systemctl enable apache2

• Check your Apache config syntax:

apachectl -t

If you get an error, you would need to fix that problem and then you could restart Apache:

systemctl restart apache2

• If you get Syntax OK when running apachectl -t then your configuration is correct, so I would recommend checking your error logs:

tail -f /var/log/apache2/error.log

With the -f argument, you would see the output of the log in real team, so you could visit your website via your browser, and you would be able to see the errors populating the log if there are any. To stop that, just press CTRL+C.

• Check the permissions of the files and folders in your document root:

Find the user that your Apache service is running as:

ps auxf | grep apache

If you are using Ubuntu, the user should be www-data, so you would need to make sure that your files and folders are owned by that user, so Apache could read and write to those files:

chown -R www-data:www-data /var/www/yourdomain.com

Note: be careful with the above command as it could mess up the ownership of all of your files if you don’t specify the path correctly.

• Check if Apache is binding to the default ports:

netstat -plant | grep '80\|443'

• Check if ufw allows TCP connections on port 80 and 443:

ufw status

If this is the case, you can follow the steps from this article here on how to configure your ufw:

https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-with-ufw-on-ubuntu-18-04

That is pretty much it, with all of the above information you should be able to narrow down the problem.

For more information I would suggest checking out this article here:

https://www.digitalocean.com/community/tutorials/how-to-troubleshoot-common-site-issues-on-a-linux-server

Hope that this helps! Regards, Bobby