One RonR applications serving hundreds of domains...how do I point many to one DNS?

I write this letter to ask what could be a simple one line answer or
require much study. I am self taught and have spent the last year
putting in 2,000 hours in developing a Ruby on Rails application that
will service hundreds of distinct domains covering a wide range of web
adventures. Each domain can select from a group of 10 modules (such as
Forum, Product Review, Candidate Listings, eBuy, etc.) that are
appropriate to the business focus. Seen another way, the RonR
application serves up distinct content for each of the 100+ domains.
I've purchased most of the books from Amazon.com covering these areas
and my method of learning is to simply read these books, again and
again! Now, I find I must learn a 'technique' for putting all this
together in a managable way. My objective is to point all my 100+
domains (www.something.com) to one DNS address (I've heard of Dynamic
DNS or CName records) and then point this one DNS record to wherever
my application and server reside. I feel this strategy is necessary if
I ever wish to change my hosting strategy without pointing each
separate .com to a new DNS address. How might I accomplish this? I am
grateful for any reply or suggestion of a book that I should purchase.
Kathleen

I write this letter to ask what could be a simple one line answer or
require much study. I am self taught and have spent the last year
putting in 2,000 hours in developing a Ruby on Rails application that
will service hundreds of distinct domains covering a wide range of web
adventures. Each domain can select from a group of 10 modules (such as
Forum, Product Review, Candidate Listings, eBuy, etc.) that are
appropriate to the business focus. Seen another way, the RonR
application serves up distinct content for each of the 100+ domains.

Wow, quite a project! Nice job.

I've purchased most of the books from Amazon.com covering these areas
and my method of learning is to simply read these books, again and
again! Now, I find I must learn a 'technique' for putting all this
together in a managable way. My objective is to point all my 100+
domains (www.something.com) to one DNS address (I've heard of Dynamic
DNS or CName records) and then point this one DNS record to wherever
my application and server reside. I feel this strategy is necessary if
I ever wish to change my hosting strategy without pointing each
separate .com to a new DNS address. How might I accomplish this? I am
grateful for any reply or suggestion of a book that I should purchase.

Exactly, www.something.com CNAME www.myapp.com for each
www.something.com you have.

Best,
jeremy

How to use subdomains without any hassle in DNS, HTTP server config, etc...

http://www.railsdev.ws/blog/10/using-subdomains-in-rails-apps/

-- gw (www.railsdev.ws)