What is the expected behaviour for multi-site setups where the uiurl needs to be different from the public site urls. Considering there is this recommendation in http://world.episerver.com/Documentation/Items/Developers-Guide/EPiServer-CMS/75/Security/Securing-edit-and-admin-user-interfaces/.
If you want to secure the UI folder on another port other to that the site is running on, add an absolute URL including a port other than 80 (or a port the application is running on) as shown below. Setting uiUrl to a custom host and port is not recommended for multi-site setups since each site have custom domains. Consider having a separate editing server instead and remove access to editing and administration interfaces on publicly facing server.uiUrl="http://localhost:8888/newuipath/"
Is this supported and why is it recommended to have a separate server for editing in multi-site setups?
It's recommended if you want an extra layer of security, it has nothing to do with multi-site per se. But if you specify a host (and port) it won't work in a multi-site setup, unless you set up one application for every website, since they all have seperate hosts and therefore need different settings. But there's really no need to specify the host. Instead of running the UI on another port, I would recommend setting it up on a seperate server outside DMZ.
If you only specify a path, and no host, in uiUrl everything will work just fine.
It would be nice if there was more documentation on the recommneded setup in multi-set scenarios.
Well, I think we, as developers, will never be happy no matter how good the documentation is :) That's why we have the forum and developer support to ask questions.
There is not one recommended setup, because everybody's needs differs. But the different scenarios are described here http://world.episerver.com/documentation/Items/Developers-Guide/EPiServer-CMS/8/Deployment/Deployment-scenarios/Deployment-scenarios/ and here http://world.episerver.com/documentation/Items/Developers-Guide/EPiServer-CMS/8/Deployment/Setting-up-multiple-sites/.
Hope that helps.