Allow specifying an optional queue namespace

README.md

@@ -61,6 +61,21 @@ class FailedPaymentConsumer
 end
 ```
 
+By default, the queue name will be named using the consumer class. You can set
+the queue name explicitly by using the `queue_name` method:
+
+```ruby
+class FailedPaymentConsumer
+  include Hutch::Consumer
+  consume 'gc.ps.payment.failed'
+  queue_name 'failed_payments'
+
+  def process(message)
+    mark_payment_as_failed(message[:id])
+  end
+end
+```
+
 If you are using Hutch with Rails and want to make Hutch log to the Rails
 logger rather than `stdout`, add this to `config/initializers/hutch.rb`
 

lib/hutch/broker.rb

@@ -93,10 +93,12 @@ def set_up_api_connection
       end
     end
 
-    # Create / get a durable queue.
+    # Create / get a durable queue and apply namespace if it exists.
     def queue(name)
       with_bunny_precondition_handler('queue') do
-        @channel.queue(name, durable: true)
+        namespace = @config[:namespace].to_s.downcase.gsub(/\W|:/, "")
+        name = name.prepend(namespace + ":") unless namespace.empty?
+        channel.queue(name, durable: true)
       end
     end
 

lib/hutch/cli.rb

@@ -166,6 +166,10 @@ def parse_options(args = ARGV)
           Hutch::Config.log_level = Logger::DEBUG
         end
 
+        opts.on('--namespace NAMESPACE', 'Queue namespace') do |namespace|
+          Hutch::Config.namespace = namespace
+        end
+
         opts.on('--version', 'Print the version and exit') do
           puts "hutch v#{VERSION}"
           exit 0

lib/hutch/config.rb

@@ -24,7 +24,8 @@ def self.initialize
         log_level: Logger::INFO,
         require_paths: [],
         autoload_rails: true,
-        error_handlers: [Hutch::ErrorHandlers::Logger.new]
+        error_handlers: [Hutch::ErrorHandlers::Logger.new],
+        namespace: nil
       }
     end
 

lib/hutch/consumer.rb

@@ -15,12 +15,19 @@ def consume(*routing_keys)
         @routing_keys = self.routing_keys.union(routing_keys)
       end
 
+      # Explicitly set the queue name
+      def queue_name(name)
+        @queue_name = name
+      end
+
       # The RabbitMQ queue name for the consumer. This is derived from the
       # fully-qualified class name. Module separators are replaced with single
       # colons, camelcased class names are converted to snake case.
-      def queue_name
+      def get_queue_name
+        return @queue_name unless @queue_name.nil?
         queue_name = self.name.gsub(/::/, ':')
-        queue_name.gsub(/([^A-Z:])([A-Z])/) { "#{$1}_#{$2}" }.downcase
+        queue_name.gsub!(/([^A-Z:])([A-Z])/) { "#{$1}_#{$2}" }
+        queue_name.downcase
       end
 
       # Accessor for the consumer's routing key.

lib/hutch/worker.rb

@@ -62,7 +62,7 @@ def setup_queues
     # Bind a consumer's routing keys to its queue, and set up a subscription to
     # receive messages sent to the queue.
     def setup_queue(consumer)
-      queue = @broker.queue(consumer.queue_name)
+      queue = @broker.queue(consumer.get_queue_name)
       @broker.bind_queue(queue, consumer.routing_keys)
 
       queue.subscribe(ack: true) do |delivery_info, properties, payload|

spec/hutch/broker_spec.rb

@@ -77,6 +77,17 @@
     end
   end
 
+  describe '#queue' do
+    let(:channel) { double('Channel') }
+    before { broker.stub(:channel) { channel } }
+
+    it 'applies a global namespace' do
+      config[:namespace] = 'service'
+      broker.channel.should_receive(:queue).with { |*args| args.first == 'service:test' }
+      broker.queue('test')
+    end
+  end
+
   describe '#bindings', rabbitmq: true do
     around { |example| broker.connect { example.run } }
     subject { broker.bindings }
@@ -97,7 +108,9 @@
   end
 
   describe '#bind_queue' do
+
     around { |example| broker.connect { example.run } }
+
     let(:routing_keys) { %w( a b c ) }
     let(:queue) { double('Queue', bind: nil, unbind: nil, name: 'consumer') }
     before { broker.stub(bindings: { 'consumer' => ['d'] }) }

spec/hutch/consumer_spec.rb

@@ -58,22 +58,42 @@ class ComplexConsumer
   end
 
   describe '.queue_name' do
-    it 'replaces module separators with colons' do
-      module Foo
-        class Bar
+    it 'overrides the queue name' do
+
+    end
+  end
+
+  describe '.get_queue_name' do
+
+    context 'when queue name has been set explicitly' do
+      it 'returns the give queue name' do
+        class Foo
           include Hutch::Consumer
+          queue_name "bar"
         end
-      end
 
-      Foo::Bar.queue_name.should == 'foo:bar'
+        Foo.get_queue_name.should == "bar"
+      end
     end
 
-    it 'converts camelcase class names to snake case' do
-      class FooBarBAZ
-        include Hutch::Consumer
+    context 'when no queue name has been set' do
+      it 'replaces module separators with colons' do
+        module Foo
+          class Bar
+            include Hutch::Consumer
+          end
+        end
+
+        Foo::Bar.get_queue_name.should == 'foo:bar'
       end
 
-      FooBarBAZ.queue_name.should == 'foo_bar_baz'
+      it 'converts camelcase class names to snake case' do
+        class FooBarBAZ
+          include Hutch::Consumer
+        end
+
+        FooBarBAZ.get_queue_name.should == 'foo_bar_baz'
+      end
     end
   end
 end

spec/hutch/worker_spec.rb

@@ -4,7 +4,7 @@
 describe Hutch::Worker do
   before { Raven.as_null_object }
   let(:consumer) { double('Consumer', routing_keys: %w( a b c ),
-                          queue_name: 'consumer') }
+                          get_queue_name: 'consumer') }
   let(:consumers) { [consumer, double('Consumer')] }
   let(:broker) { Hutch::Broker.new }
   subject(:worker) { Hutch::Worker.new(broker, consumers) }
@@ -24,7 +24,7 @@
     before { broker.stub(queue: queue, bind_queue: nil) }
 
     it 'creates a queue' do
-      broker.should_receive(:queue).with(consumer.queue_name).and_return(queue)
+      broker.should_receive(:queue).with(consumer.get_queue_name).and_return(queue)
       worker.setup_queue(consumer)
     end