Apache User Authentication Logic ...

I'd appreciate if you can point out some links, or if anyone is willing to help me for a fee, we can talk about it.

I have a web application called MyApp

- Each MyApp user has 5gb hosting, and a web interface to manage their files.

- Therefore MyApp user gets a user account on linux machine and has access to only one directory /repo/usr/<user_id> and nowhere else. (suexec?)

- If that MyApp user creates a subdomain from any folder inside his home folder (he can do that using web interface), that folder is readable by www-data user not writable.

- That myapp user is able to mount/unmount his own ftp drives using curlftpfs.

- In short, users can only mess with their own files and they have no access nor rights to any other file that is outside of their home dir.

In short, this is a kind of hosting company server setup. Right now, we will have to manage all this from -only- one powerful server.