build file? install rails app?

In java ANT is used to build java applications. For a RoR application, is there anything which does remotely the same thing?

Because I wanted a repeatable process I created a ruby script which:

1. drops then creates the db 2. deletes the directory 3. does all the "rails", "rake", "script/server" commands 4. modifies the database.yml and class files 5. starts WEBrick

I like the idea, but it's impossibly kludgy, fragile and spammy.
However, it does accomplish the purpose of serving as documentation for me to recreate another rails project.

Once you have something mocked up to the point where you can do some data entry, and maybe a query, what then? At certain stages "script/server migrate", "rake db:migrate" or "script/server scaffold <model> <controller>" would need to be re-run.

How do you know which one to do and when? I guess since it "works" I fear breaking it! Of course, it will break, repeatedly, as I learn how to use rails, but...

Just looking for pointers.

Also, what I'm interested in doing would be a rails application for which there's a "one click installer" for. Is this possible? I'm working towards an RSS aggregator and would like to offer a one-click-install (meaning a ruby build file) to at least get the ruby parts working.

I wouldn't want to be able to install rails itself nor the database, just the rails application itself. I guess, in Gentoo, that might be accomplished with an ebuild?

Ahem, also: how do you get rails to "do" something? By which I mean have a button/link/whatever which would cause the rails app to run the ruby script which would grab RSS feeds, or web pages, or e-mails from imap, or what-have-you? There must be some way of starting that from within rails.