Apache url filtering corrupts compressed output.

While trying to set up Hudson behind apache again, I kept on getting garbage out.
After some googling I realized Hudson compress its output, therefore you can not use the normal proxy-html filter to modify urls coming from hudson:

SetOutputFilter proxy-html

Instead you can use the following:

SetOutputFilter INFLATE;proxy-html;DEFLATE
ProxyHTMLURLMap http://your_server:8080/hudson /hudson

http://wiki.uniformserver.com/index.php/Reverse_Proxy_Server_2:_mod_proxy_html_2
But since hudson seems to be well behaved it even better to just not use SetOutputFilter and ProxyHTMLURLMap.

http://wiki.hudson-ci.org/display/HUDSON/Running+Hudson+behind+Apache

Symbolic link not allowed

I got the following nasty exception in my /var/log/apache2/error_log,
and it took me too long to figure out how to fix it:

Symbolic link not allowed or link target not accessible: /opt/gforge5/plugins/scmbzr

Where in my case /opt/gforge5/plugins/scmbzr is a symlink to somewhere else.
I checked and rechecked all my permissions, but nothing worked.

So eventually it turns out that for every directory in the path where you have symlinks, you need something like:

<directory>
    Options FollowSymLinks
</directory>

(because I have a symlink in plugins called scmbzr)

Thanks a LOT to Ivan Van Laningham who mentioned this on some mailinglist:
http://www.mail-archive.com/mailman-users@python.org/msg44430.html