[OS X Server 5.x] httpd.conf location
The httpd.conf file controlled by the Server.app is stored at
/Library/Server/Web/Config/apache2/httpd_server_app.conf
If you happen to update PHP or other Apache modules through non-Apple methods (e.g. homebrew), then this is where you add your LoadModule and FilesMatch arguments.
You MUST restart the web server through the Server.app for changes to load. apachectl graceful will not load the changes in httpd_server_app.conf.
#This article is in response to “Update PHP on OS X Server 5.x”.