Merge pull request forward3d#29 from Futurelearn/access-server-tags

Provide access to EC2 server tags in Capistrano recipes

lib/cap-ec2/capistrano.rb

@@ -21,17 +21,25 @@ def ec2_handler
 
       def ec2_role(name, options={})
         ec2_handler.get_servers_for_role(name).each do |server|
-          env.role(name, CapEC2::Utils.contact_point(server), options)
+          env.role(name, CapEC2::Utils.contact_point(server),
+                   options_with_instance_id(options, server))
         end
       end
 
       def env
         Configuration.env
       end
 
+      private
+
+      def options_with_instance_id(options, server)
+        options.merge({aws_instance_id: server.instance_id})
+      end
+
     end
   end
 end
 
 self.extend Capistrano::DSL::Ec2
 
+Capistrano::Configuration::Server.send(:include, CapEC2::Utils::Server)

lib/cap-ec2/ec2-handler.rb

@@ -74,6 +74,12 @@ def get_servers_for_role(role)
       servers.flatten.sort_by {|s| s.tags["Name"] || ''}
     end
 
+    def get_server(instance_id)
+      @ec2.reduce([]) do |acc, (_, ec2)|
+        acc << ec2.instances[instance_id]
+      end.flatten.first
+    end
+
     private
 
     def instance_has_tag?(instance, key, value)

lib/cap-ec2/utils.rb

@@ -1,6 +1,13 @@
 module CapEC2
   module Utils
 
+    module Server
+      def ec2_tags
+        id = self.properties.fetch(:aws_instance_id)
+        ec2_handler.get_server(id).tags
+      end
+    end
+
     def project_tag
       fetch(:ec2_project_tag)
     end