template.rb

Resources do
  [:cthulhu, :hastur, :nyar].each {|name|
    _(name) do
      Type "AWS::EC2::Instance"

      Properties do
        # amzn-ami-pv-2013.09.2.x86_64-ebs
        ImageId "ami-0d13700c"
        InstanceType "t1.micro"
        KeyName "XXX"

        NetworkInterfaces [
          _{
            DeviceIndex 0
            SubnetId "subnet-XXXXXXXX"
            AssociatePublicIpAddress true
          }
        ]

        UserData do
          Fn__Base64 (<<-EOS).fn_join
            #!/bin/bash
            /opt/aws/bin/cfn-init -s <%= Ref "AWS::StackName" %> -r #{name} --region <%= Ref "AWS::Region" %>
            /opt/aws/bin/cfn-signal -e 0 '<%= Ref "#{name}WaitHandle" %>'
          EOS
        end

        Tags [
          _{
            Key "Name"
            Value name
          }
        ]
      end # Properties

      Metadata do
        AWS__CloudFormation__Init do
          config do
            commands do
              setup_command do
                command (<<-EOS).fn_join
                  echo `hostname` > /tmp/hostname
                EOS
              end
            end
          end
        end
      end
    end

    _("#{name}WaitHandle") do
      Type "AWS::CloudFormation::WaitConditionHandle"
    end

    _("#{name}WaitCondition") do
      Type "AWS::CloudFormation::WaitCondition"
      DependsOn name

      Properties do
        Handle { Ref "#{name}WaitHandle" }
        Timeout 300
      end
    end
  } # end of each
end