How do I configure a reverse proxy to only proxy by file extension?

Question

Let's say I have a vhost with a DocumentRoot and ProxyPass to an application server. I want the proxy to only forward requests with an extension of .xyz and .abc, but everything else should default to the doc root. How can I achieve that?

Answer 1

Use LocationMatch:

<LocationMatch \.xyz$>
  ProxyPass http://some.where/else
</Locationmatch>

NOTE that since you are already providing an exact location, ProxyPass no longer requires one.