I'm happy to announce test packages of a new Ruby on Rails 4.2 collection are available from the CentOS Software Collections SIG.
These are modelled on previous collections (e.g. rh-ror41) and provide all of Rails with full asset compilation support, plus extras such as jQuery (1.11.2 & 2.1.3). It depends on the rh-ruby22 and v8314 collections.
To install it, run:
yum install centos-release-scl yum install --enablerepo=centos-sclo-sclo-testing --nogpgcheck sclo-ror42
Activate and use the collection with "scl enable sclo-ror42".
https://wiki.centos.org/SpecialInterestGroup/SCLo/RubyOnRails contains tips on using the RoR collection(s) with Passenger.
Please test the collection out and report bugs to https://github.com/domcleal/sclo-ror42/issues or on this thread.