Setting up nginx for use with Discourse

I am trying to install Discourse for a domain on a CentOS server. I think I have installed all of the necessary components by following this guide:

However, I am not sure what I need to enter in /etc/nginx/conf.d/discourse.conf for server_name. At the moment I have:

server {
    listen       80;
    server_name  psychematters.net www.psychematters.net;

Where psychematters.net is one domain of many on my server, the one that I would like to use Discourse on.

When I start nginx it affects all of the domains on my server though, with a “Welcome to nginx” message showing on the home page of each site.

What do I need to do to get this working properly, such that I can use Discourse on just the psyche matters.net site?

Do I need to make any changes to /etc/nginx/conf.d/default.conf, which currently has the following for server?:

server {
    listen       80;
    server_name  localhost;

You may be interested in this: