Using a CentOS 7 box running a Plex Media Server and an Apache reverse proxy on the same box without a domain name and only an IP address and after much trial and error, a working Apache configuration file finally materializes.
The goal was to eliminate the need of typing the port number to access the Plex Media Server web browser interface. The out-of-box web address may look something like this, http://IP.AD.DR.ESS:32400/web/index.html. The goal, http://IP.AD.DR.ESS/web.
Using an existing Apache reverse proxy, a configuration file was created and added to the directory, /ect/httpd/conf.d as plex.conf for example.
ProxyRequests Off ProxyPreserveHost On ProxyPass / http://IP.AD.DR.ESS:32400/ ProxyPassReverse / http://IP.AD.DR.ESS:32400/ RewriteCond %{REQUEST_URI} !^/web RewriteCond %{HTTP:X-Plex-Device} ^$ RewriteCond %{QUERY_STRING} (^|&)X-Plex-Device=(&|$) [OR] RewriteCond %{QUERY_STRING} !(^|&)X-Plex-Device= RewriteRule ^/$ /web/\ [R,L]
This one works too. Tested 8/22/2019.
ProxyRequests Off roxyPreserveHost On ProxyPass / http://127.0.0.1:32400/ ProxyPassReverse / http://127.0.0.1:32400/ RewriteEngine on RewriteCond %{REQUEST_URI} !^/web RewriteCond %{HTTP:X-Plex-Device} ^$ RewriteRule ^/$ /web/\ [R,L]
Once completed, the Apache service was reloaded/restarted and the configuration takes immediate effect. The goal is achieved with http://IP.AD.DR.ESS/web.
Source(s)
http://matt.coneybeare.me/how-to-map-plex-media-server-to-your-home-domain/