We all know how to do VirtualHosts on Apache, but what if you want to run a web application inside a container, or on another box, or in a virtual machine?
You need to turn Apache in to a reverse proxy. This is also called a gateway. It’s operation is pretty straightforward, and described in the Apache2 docs:
ProxyPass "/foo" "http://example.com"
That’s pretty simple. When the user hits /foo, they get the pages from example.com.
You can use the ProxyPass directive in a VirtualHost section.
On Debian systems, you set up virtual hosts with separate config files. My current one looks like this:
<VirtualHost 188.8.131.52:80> ServerName slaptech.net ProxyPass "/" "http://example.com/" ProxyPassReverse "/" "http://example.com/" </VirtualHost>
Again, it’s pretty straightforward. I have a domain, slaptech.net, that resolves to the above IP address.
When the Host header matches slaptech.net, it matches this VirtualHost scope. The server then maps the root of the URL, / , to requests at example.com.