Load two Ruby Modules/Gems with the same name

Question

I\'m trying to use two Gems to access Amazon Web Services (AWS). One is the Amazon \'aws-sdk\', the other is \'amazon-ec2\'. I\'m using the second as the aws-sdk does not

Answer 1

In Ruby, modules with the same name from different gems don't replace each other. If one gem implements

module AWS
  class Foo
  end
end

and another implements

module AWS
  class Bar
  end
end

and you require them both, you will end up with an AWS module that contains both a class Foo and a class Bar (unless the second does something really tricky like explicitly undefining anything already present in the module, before defining its own stuff, which is very unlikely). As long as the second gem doesn't redefine any methods in the first gem (or attempts to use a module as a class or vice versa), they should both work fine. I think you may be looking for the wrong solution.

Edit: And in fact, what happens for me (in an environment with only these gems present (aws-sdk 1.2.3 and amazon-ec2 0.9.17) and the exact code you listed above) is exactly that:

.rvm/gems/ree-1.8.7-2011.03@ec2/gems/amazon-ec2-0.9.17/lib/AWS/EC2.rb:2: EC2 is not a module (TypeError)

Could it be that an error gets swallowed somewhere and that the module AWS::Cloudwatch hasn't been defined, simply because the initialization of the gem goes awry?