I can't believe that it turned out to be so difficult, but I need to be able to run my rails app at localhost/rails_app for development reasons, without breaking other applications I have. (localhost/php_app, for example)
I've followed a lot of tutorials, but I still can't get it working.
I have passenger installed and I think the missing step is to properly configure a VirtualHost.
(Mac OS X, Rails 4, Apache)
Edit: The big problem is that I can't run in localhost:3000 or any other port
Edit2:
With this in the apache configuration file:
<VirtualHost *:80>
ServerName localhost
ProxyRequests off
<Proxy *>
Order deny,allow
Allow from all
</Proxy>
<Location /my_rails_app/ >
ProxyPass http://localhost:3000/
ProxyPassReverse http://localhost:3000/
</Location>
</VirtualHost>
The application runs on localhost/my_rails_app/ but it still uses localhost/ as the base url, missing every asset and making all the links wrong.