Get familiar with rbenv & ruby-build.
rvm is cool, but rbenv & ruby-build are cooler. They work really well in development and, most importantly, they're simple. Simple is good. If you insist on using rvm, here's the chef cookbook.
This cookbook sets up rbenv and ruby-build system-wide. It won't allow
users to install rubies or gems. This is intentional. There's bundler,
all apps should come packaged with all dependencies and installed from
vendor/cache. If you listen and don't go against those conventions
you'll save yourself a lot of unnecessary hassle.
System gems are controlled via node[:rbenv][:global_gems], they will
be kept updated across all rubies installed via
node[:ruby_build][:rubies].
The cookbook cleanly separates rbenv from ruby-build, you can have one
without the other. It also knows how to cleanup, just pass :action => "anything-but-install" to either node[:rbenv] or node[:ruby_build].
I'm sticking to the lastest stable versions, but since I'm setting both of them from git repositories, feel free to overwrite this (it can be any git reference).
If you'll include bootstrap into your cookbooks, all
:system_users that belong to the rbenv group will get rbenv setup
in their user profile for free. Check bootstrap_profile provider
for implementation details.