When updating Rails, be careful to update to the specific version you want. Blindly updating Rails to the latest version will break things. Anyone in the cnetsadm group can "sudo gem".

You can check the required version of Rails by looking in {RAILS_ROOT}/config/environment.rb and looking for this: RAILS_GEM_VERSION = 'x.y.z' unless defined? RAILS_GEM_VERSION

At this writing, RAILS_GEM_VERSION is set to 2.0.2, so in order to update the rails installation on smithers to that version, we type:

sudo gem install rails --version 2.0.2

There will be some confirmation messages. Generally, say yes to confirmations to install dependencies. The final dialogue should run something like this (from an update run on April 25, 2009):

[jburgoon@smithers givealink]$ sudo gem install rails --version 2.0.2

Password:

Bulk updating Gem source index for: http://gems.rubyforge.org

Install required dependency activesupport? [Yn] y

Install required dependency activerecord? [Yn] y

Install required dependency actionpack? [Yn] y

Install required dependency actionmailer? [Yn] y

Install required dependency activeresource? [Yn] y

Successfully installed rails-2.0.2

Successfully installed activesupport-2.0.2

Successfully installed activerecord-2.0.2

Successfully installed actionpack-2.0.2

Successfully installed actionmailer-2.0.2

Successfully installed activeresource-2.0.2

Installing ri documentation for activesupport-2.0.2...

Installing ri documentation for activerecord-2.0.2...

Installing ri documentation for actionpack-2.0.2...

Installing ri documentation for actionmailer-2.0.2...

Installing ri documentation for activeresource-2.0.2...

Installing RDoc documentation for activesupport-2.0.2...

Installing RDoc documentation for activerecord-2.0.2...

Installing RDoc documentation for actionpack-2.0.2...

Installing RDoc documentation for actionmailer-2.0.2...

Installing RDoc documentation for activeresource-2.0.2...