Fix parsing of StatsD metrics with Py3

When running with Py3 we compare a byte string to a unicode string
when parsing StatsD metrics. This patch adds some unit tests to
reproduce the bug and decodes the bytestring to make the existing
comparisons valid under Py3. When backporting to Train we can use
Oslo encodeutils. Clearly we could have more unit tests, but
this makes a start.

Change-Id: I6341f96f5c186428d2d829cabf618a6f84f40ce2
Story: 2007684
Task: 39796
(cherry picked from commit a2400fc)

monasca_agent/statsd/udp.py

@@ -16,6 +16,8 @@
 import select
 import socket
 
+from oslo_utils import encodeutils
+
 import monasca_agent.common.metrics as metrics_pkg
 
 log = logging.getLogger(__name__)
@@ -159,6 +161,7 @@ def _parse_dogstatsd_tags(statsd_msg):
     def submit_packets(self, packets):
         for packet in packets.split(b"\n"):
 
+            packet = encodeutils.safe_decode(packet)
             if not packet.strip():
                 continue
 

tests/test_statsd.py

@@ -0,0 +1,49 @@
+import mock
+import unittest
+
+import monasca_agent.common.metrics as metrics_pkg
+import monasca_agent.statsd.udp as udp
+
+
+class TestStatsd(unittest.TestCase):
+    def testSubmitPacket(self):
+        mock_aggregator = mock.Mock()
+        srv = udp.Server(mock_aggregator, 'localhost', 1234)
+        test_packet = b"monasca.log.out_logs_truncated_bytes:0|g|#" \
+            b"{'service': 'monitoring', 'component': 'monasca-log-api'}"
+        srv.submit_packets(test_packet)
+        mock_aggregator.submit_metric.assert_called_once_with(
+            'monasca.log.out_logs_truncated_bytes',
+            0,
+            metrics_pkg.Gauge,
+            dimensions={
+                'service': 'monitoring',
+                'component': 'monasca-log-api'},
+            sample_rate=1)
+
+    def testSubmitPackets(self):
+        mock_aggregator = mock.Mock()
+        srv = udp.Server(mock_aggregator, 'localhost', 1234)
+        test_packet = b"monasca.log.out_logs_truncated_bytes:0|g|#" \
+            b"{'service': 'monitoring', 'component': 'monasca-log-api'}\n" \
+            b"application_metric:10|c|#{'service': 'workload'}"
+        srv.submit_packets(test_packet)
+        mock_aggregator.submit_metric.assert_has_calls([
+            mock.call(
+                'monasca.log.out_logs_truncated_bytes',
+                0,
+                metrics_pkg.Gauge,
+                dimensions={
+                    'service': 'monitoring',
+                    'component': 'monasca-log-api'},
+                sample_rate=1
+            ),
+            mock.call(
+                'application_metric',
+                10,
+                metrics_pkg.Counter,
+                dimensions={
+                    'service': 'workload'},
+                sample_rate=1
+            )
+        ])