Many of our projects (student projects as well as research projects) run on one of our local machines, for example on ''vulcano.informatik.privat:8400'', but should be accessible from the outside, for example via ''http://aqqu.cs.uni-freiburg.de/proxy-test''. This is non-trivial, if the latter URL is not only a top-level URL, like ''http://aqqu.cs.uni-freiburg.de'' but contains a path, like the ''/proxy-test''.

== Apache Config ==

The first step is to find out, which virtual host deals with the domain. In the example above, it's the Apache virtual host configured in ''filicudi:/etc/apaches2/sites-available/aqqu.conf'' and it contains (among others) the following lines:

{{{
<VirtualHost *:80>
  ServerName aqqu.informatik.uni-freiburg.de
  ServerAlias aqqu aqqu.cs.uni-freiburg.de
 
  [...]

  ProxyPass /proxy-test http://vulcano.informatik.privat:8400
  ProxyPassReverse /proxy-test http://vulcano.informatik.privat:8400
  
  [...]

</VirtualHost>
}}}

The effect of the ''!ProxyPass'' line is that when somebody types ''http://aqqu.cs.uni-freiburg.de/proxy-test/<something>'' in the browser, then ''vulcano.informatik.privat:8400'' gets the request ''/<something>''. Note that details like a trailing / or not in the line in the configuration file are important.

TODO: explain the effect of the ''!ProxyPassReverse'' line and why and when it is needed.