Configure external env with origin detection (#316)

Author: StephenWakely

lib/datadog/statsd.rb

@@ -124,7 +124,7 @@ def initialize(
       origin_detection_enabled = origin_detection_enabled?(origin_detection)
       container_id = get_container_id(container_id, origin_detection_enabled)
 
-      external_data = sanitize(ENV['DD_EXTERNAL_ENV'])
+      external_data = sanitize(ENV['DD_EXTERNAL_ENV']) if origin_detection_enabled
 
       @serializer = Serialization::Serializer.new(prefix: @prefix,
                                                   container_id: container_id,

lib/datadog/statsd/telemetry.rb

@@ -40,7 +40,7 @@ def initialize(flush_interval, container_id, external_data, cardinality, global_
       end
 
       def would_fit_in?(max_buffer_payload_size)
-        MAX_TELEMETRY_MESSAGE_SIZE_WT_TAGS + serialized_tags.size < max_buffer_payload_size
+        MAX_TELEMETRY_MESSAGE_SIZE_WT_TAGS + serialized_tags.size + serialized_fields.size < max_buffer_payload_size
       end
 
       def reset

spec/matchers/telemetry_matcher.rb

@@ -16,20 +16,24 @@ def add_telemetry(text,
                     packets_dropped: 0,
                     packets_dropped_queue: 0,
                     packets_dropped_writer: 0,
-                    transport: 'udp')
+                    transport: 'udp',
+                    external_env: '',
+                    container: '')
+    external_env = "|e:#{external_env}" unless external_env.empty?
+    container = "|c:#{container}" unless container.empty?
     [
       text,
-      "datadog.dogstatsd.client.metrics:#{metrics}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
-      "datadog.dogstatsd.client.events:#{events}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
-      "datadog.dogstatsd.client.service_checks:#{service_checks}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
-      "datadog.dogstatsd.client.bytes_sent:#{bytes_sent}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
-      "datadog.dogstatsd.client.bytes_dropped:#{bytes_dropped}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
-      "datadog.dogstatsd.client.bytes_dropped_queue:#{bytes_dropped_queue}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
-      "datadog.dogstatsd.client.bytes_dropped_writer:#{bytes_dropped_writer}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
-      "datadog.dogstatsd.client.packets_sent:#{packets_sent}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
-      "datadog.dogstatsd.client.packets_dropped:#{packets_dropped}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
-      "datadog.dogstatsd.client.packets_dropped_queue:#{packets_dropped_queue}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
-      "datadog.dogstatsd.client.packets_dropped_writer:#{packets_dropped_writer}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}",
+      "datadog.dogstatsd.client.metrics:#{metrics}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
+      "datadog.dogstatsd.client.events:#{events}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
+      "datadog.dogstatsd.client.service_checks:#{service_checks}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
+      "datadog.dogstatsd.client.bytes_sent:#{bytes_sent}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
+      "datadog.dogstatsd.client.bytes_dropped:#{bytes_dropped}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
+      "datadog.dogstatsd.client.bytes_dropped_queue:#{bytes_dropped_queue}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
+      "datadog.dogstatsd.client.bytes_dropped_writer:#{bytes_dropped_writer}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
+      "datadog.dogstatsd.client.packets_sent:#{packets_sent}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
+      "datadog.dogstatsd.client.packets_dropped:#{packets_dropped}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
+      "datadog.dogstatsd.client.packets_dropped_queue:#{packets_dropped_queue}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
+      "datadog.dogstatsd.client.packets_dropped_writer:#{packets_dropped_writer}|c|#client:ruby,client_version:#{Datadog::Statsd::VERSION},client_transport:#{transport}#{container}#{external_env}",
     ].join("\n")
   end
 

spec/statsd_spec.rb

@@ -10,12 +10,12 @@
       tags: tags,
       logger: logger,
       telemetry_flush_interval: -1,
-      # Only turn off origin detection for linux, other
-      # platforms should work as before even with it enabled.
-      origin_detection: !RUBY_PLATFORM.include?("linux"),
+      origin_detection: origin_detection,
+      container_id: container_id,
     )
   end
 
+  let(:container_id) { nil }
   let(:namespace) { 'sample_ns' }
   let(:sample_rate) { nil }
   let(:tags) { %w[abc def] }
@@ -25,6 +25,11 @@
     end
   end
   let(:log) { StringIO.new }
+  let(:origin_detection) do
+      # Only turn off origin detection for linux, other
+      # platforms should work as before even with it enabled.
+      !RUBY_PLATFORM.include?("linux")
+  end
 
   before do
     allow(Socket).to receive(:new).and_return(socket)
@@ -1295,4 +1300,44 @@ class Datadog::Statsd::SomeClass; end
       expect(socket.recv[0]).to eq_with_telemetry 'stat:1|c|#yolo'
     end
   end
+
+  describe 'External env' do
+    let(:tags) { nil }
+
+    before do
+      ENV['DD_EXTERNAL_ENV'] = 'it-false,cn-nginx-webserver,pu-75a2b6d5-3949-4afb-ad0d-92ff0674e759'
+    end
+
+    context 'with origin detection configured on' do
+      let(:origin_detection) { true }
+      let(:container_id) { "container" }
+
+      it 'outputs the external env value' do
+        subject.gauge('thing', 42)
+        subject.flush(sync: true)
+
+        # With the lengthy external env being included in the telemetry payload, we send multiple payloads
+        # and need to capture them all.
+        packets = []
+        while (packet = socket.recv)
+          packets << packet[0]
+        end
+        combined_message = packets.join("\n")
+
+        expect(combined_message).to eq_with_telemetry('sample_ns.thing:42|g|c:container|e:it-false,cn-nginx-webserver,pu-75a2b6d5-3949-4afb-ad0d-92ff0674e759',
+                                                      container: 'container', external_env: 'it-false,cn-nginx-webserver,pu-75a2b6d5-3949-4afb-ad0d-92ff0674e759') 
+      end
+    end
+
+    context 'with origin detection configured off' do
+      let(:origin_detection) { false }
+
+      it 'does not output the external env value' do
+        subject.gauge('thing', 42)
+        subject.flush(sync: true)
+
+        expect(socket.recv[0]).to eq_with_telemetry 'sample_ns.thing:42|g'
+      end
+    end
+  end
 end