Optionally filter data reported to Librato Metrics

lib/metriks/reporter/librato_metrics.rb

@@ -15,6 +15,9 @@ def initialize(email, token, options = {})
       @registry  = options[:registry] || Metriks::Registry.default
       @time_tracker = Metriks::TimeTracker.new(options[:interval] || 60)
       @on_error  = options[:on_error] || proc { |ex| }
+
+      @only   = options[:only]   || :all
+      @except = options[:except] || :none
     end
 
     def start
@@ -86,6 +89,18 @@ def write
       gauges.flatten!
 
       unless gauges.empty?
+        unless @only == :all
+          gauges.select! do |gauge|
+            @only.include? gauge[:name]
+          end
+        end
+
+        unless @except == :none
+          gauges.reject! do |gauge|
+            @except.include? gauge[:name]
+          end
+        end
+
         submit(form_data(gauges.flatten))
       end
     end

test/librato_metrics_reporter_test.rb

@@ -31,4 +31,49 @@ def test_write
 
     @reporter.write
   end
-end
+
+  def test_report_specific_gauges
+    reports = %w( meter.testing.one_minute_rate counter.testing.count )
+    @reporter = build_reporter :only => reports
+
+    @registry.meter('meter.testing').mark
+    @registry.counter('counter.testing').increment
+
+    actual_reports = []
+    @reporter.expects(:submit).with do |data|
+      data.inject(actual_reports) do |actual_reports, (key, value)|
+        actual_reports << value if key.end_with?('[name]')
+        actual_reports
+      end
+    end
+
+    @reporter.write
+
+    assert_equal reports, actual_reports
+  end
+
+  def test_omit_specific_gauges
+    @reporter = build_reporter :except => %w( meter.testing.one_minute_rate
+                                              counter.testing.count )
+
+    @registry.meter('meter.testing').mark
+    @registry.counter('counter.testing').increment
+
+    actual_reports = []
+    @reporter.expects(:submit).with do |data|
+      data.inject(actual_reports) do |actual_reports, (key, value)|
+        actual_reports << value if key.end_with?('[name]')
+        actual_reports
+      end
+    end
+
+    @reporter.write
+
+    expected_reports = %w( meter.testing.five_minute_rate
+                           meter.testing.fifteen_minute_rate
+                           meter.testing.mean_rate
+                           meter.testing.count )
+
+    assert_equal expected_reports, actual_reports
+  end
+end