Multiple sites with customisations on a single app

Hi everyone

This is my first time on the RoR list so hello all!

We are writing a CMS using Rails to host multiple sites. Many of our
clients’ sites are simple four- to six-page sites with one or two
custom controllers per site. We are writing the generic CMS code as an
Engine so that a) updates can be rolled out to multiple sites with
minimal effort, b) it can be applied retrospectively to existing Rails
apps and c) we CAN have custom controllers on a site-by-site basis
because each site will be it’s own app.

However, we’re also investigating the feasibility of writing a single
app that will host multiple sites so we can save on server resources
and keep our hosting prices down. This wouldn’t be a problem normally
but we would still like to allow small customisations site-by-site and
keep those customisations separated from sibling apps. Almost like
having micro Engines for each site that are visible only to the
relevant site.

Has anyone had any experience with setting up something of this
nature? Any suggestions to offer? Just looking for ideas to see if
it’s going to be feasible or not.

BTW, I’m familiar with “why engines are evil” so hopefully no one
decides to deviate from my question to discuss this :wink: