How do you migrate an existing Apache server, to a brand new nginx installation for several websites that use PHP? This is a simple tutorial into changing an Apache installation into a nginx one, without having to change your existing websites.
nginx is a server that scales far better compared to apache running on the same hardware. The tutorial is not super CentOS specific, but all the commands were run on a CentOS.
The Apache server that was migrated, namely this blog, has several virtual hosts, that are all running PHP, some of them Joomla websites. The plan is to take them as they are, and have them available externally the same way as before, using the same virtual host names, the same folder locations, with the same users assigned to them.
The reason is that if we screw up something in the process, we can just revert to our old proven Apache, by just restarting the Apache service and shutting down nginx. Also we can minimize the downtime, since if done right it should be in the end just shutting down apache and starting nginx, but if it doesn't work we can quickly go back to serving the files with Apache until we figure out what is going on.
While it is simple, it is a pretty long read, so grab your coffee, and hack away:
1. Install nginx
This is as simple as running:
Make sure the /etc/nginx/conf.d/default.conf has the paths pointing to /var/www/html, or whatever was the default site for your Apache configuration. (In my case it was /var/www/blog).