Hey all,
I have a question about how to setup citadel properly together with apache2.
Everything is installed accordingly to the guides on my linode. This means both apache and citadel run on port 80. This doesn't seem to be a problem as long as apache starts first, but when rebooting it looks like citadel is blocking port 80 and then apache is unable to start. I currently solve this by stopping citadel, starting apache and then start citadel.

Does anyone know a more sustainable solution to this?

I have never used citadel myself but one thing is sure: there is no way that running two different daemons on the same port and same IP will work. The following link may help:
http://www.citadel.org/doku.php/faq:ins ... pacheproxy

As mentioned by Sanvila, it is impossible for 2 applications to be listening on the same port.

As you noticed, if Citadel starts first, the port becomes in use and Apache can't connect.
If you stop Citadel, the port becomes unused, and Apache can claim it. Restarting Citadel after does not fix the issue as you now have Apache on 80, and Citadel.. well.. not.

You can forward requests to a different port which Citadel can be listening on through Apache though