Plesk may have gotten built-in RoR support by now, but i haven’t got a clue whether it works or not.
On our dedicated server, we use vhost.conf to pass all rails related requests to pound which balances the requests over one or more mongrels (http://forums.rimuhosting.com/forums/showthread.php?t=389). If you don’t have root access, you’re out of luck here, you’ll have to rely on the goodwill of your hosting provider to do this kind of setup for you. Once it’s setup however, getting ssh access to your own account should enable you to use capistrano to deploy your railsapp and restart your mongrel/mongrel_cluster.
We only got Plesk to enable our customers to create new e-mail addresses and host static or php sites on subdomains etc. We manage the rails apps ourselves. All these control panels have the nasty habit of fooling around with permissions and keeping to their own way of structuring domain related folders. As a hosting provider you’re just better off shielding the customer from it.
Using plesk as an example, they put account files in /var/www/vhosts/mydomain.com/(subdomains/subdomainname/), cpanel probably uses something like /home/username/. You really need to get familiar with all of this when you want to reliably host rails applications on them.
Now, the problem with shared hosting, and especially the cheap ones, is that they have to manage a lot of servers with thousands of accounts. A lot of them outsource their support and even server management to low wage countries. When it comes to solving problems related to rails deployment, you’ll have to go through escalation after escalation to finally get to a person that is quite linux knowledgable, but clearly overstressed. The last thing he’ll want to do is help you out by customizing his already very fragile server setup. I gave up on shared hosting after going through these kind of horror stories (and I’m being so kind not to go into detail on how I was treated by some of them) and living a carefree and happy-customers life for a couple of bucks extra per month. And if I need support, rimuhosting’s is just unbelievably good, I just can’t praise them enough for it.
Peter De Berdt