Add flask functional test for exemplars

Author: tammy-baylis-swi

tests/opentelemetry-docker-tests/tests/flask/test_flask_functional.py

@@ -0,0 +1,109 @@
+# Copyright The OpenTelemetry Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from flask import Flask
+
+from opentelemetry import metrics as metrics_api
+from opentelemetry.instrumentation.flask import FlaskInstrumentor
+from opentelemetry.sdk.metrics import AlwaysOnExemplarFilter
+from opentelemetry.test.globals_test import (
+    reset_metrics_globals,
+)
+from opentelemetry.test.test_base import TestBase
+from opentelemetry.trace import (
+    INVALID_SPAN_ID,
+    INVALID_TRACE_ID,
+)
+
+class TestFunctionalFlask(TestBase):
+    def setUp(self):
+        super().setUp()
+        self.memory_exporter.clear()
+        # This is done because set_meter_provider cannot override the
+        # current meter provider.
+        reset_metrics_globals()
+        (
+            self.meter_provider,
+            self.memory_metrics_reader,
+        ) = self.create_meter_provider(
+            exemplar_filter=AlwaysOnExemplarFilter(),
+        )
+        metrics_api.set_meter_provider(self.meter_provider)
+
+        self._app = Flask(__name__)
+        @self._app.route("/test/")
+        def test_route():
+            return "Test response"
+
+        self._client = self._app.test_client()
+
+        FlaskInstrumentor().instrument_app(
+            self._app,
+            meter_provider=self.meter_provider,
+        )
+
+    def tearDown(self):
+        FlaskInstrumentor().uninstrument()
+        super().tearDown()
+
+    def test_duration_metrics_exemplars(self):
+        """Should generate exemplars with trace and span IDs for Flask HTTP requests."""
+        self._client.get("/test/")  
+        self._client.get("/test/")
+        self._client.get("/test/")
+        
+        metrics_data = self.memory_metrics_reader.get_metrics_data()
+        self.assertIsNotNone(metrics_data)
+        self.assertTrue(len(metrics_data.resource_metrics) > 0)
+
+        duration_metric = None
+        metric_names = []
+        for resource_metric in metrics_data.resource_metrics:
+            for scope_metric in resource_metric.scope_metrics:
+                for metric in scope_metric.metrics:
+                    metric_names.append(metric.name)
+                    if metric.name in ["http.server.request.duration", "http.server.duration"]:
+                        duration_metric = metric
+                        break
+                if duration_metric:
+                    break
+            if duration_metric:
+                break
+        
+        self.assertIsNotNone(duration_metric)        
+        data_points = list(duration_metric.data.data_points)
+        self.assertTrue(len(data_points) > 0)
+
+        exemplar_count = 0
+        for data_point in data_points:
+            if hasattr(data_point, 'exemplars') and data_point.exemplars:
+                for exemplar in data_point.exemplars:
+                    exemplar_count += 1
+                    # Exemplar has required fields and valid span context
+                    self.assertIsNotNone(exemplar.value)
+                    self.assertIsNotNone(exemplar.time_unix_nano)
+                    self.assertIsNotNone(exemplar.span_id)
+                    self.assertNotEqual(exemplar.span_id, INVALID_SPAN_ID)
+                    self.assertIsNotNone(exemplar.trace_id)
+                    self.assertNotEqual(exemplar.trace_id, INVALID_TRACE_ID)
+                                        
+                    # Trace and span ID of exemplar are part of finished spans
+                    finished_spans = self.memory_exporter.get_finished_spans()
+                    finished_span_ids = [span.context.span_id for span in finished_spans]
+                    finished_trace_ids = [span.context.trace_id for span in finished_spans]
+                    self.assertIn(exemplar.span_id, finished_span_ids)
+                    self.assertIn(exemplar.trace_id, finished_trace_ids)
+        
+        # At least one exemplar was generated
+        self.assertGreater(exemplar_count, 0)

tests/opentelemetry-docker-tests/tests/test-requirements.txt

@@ -24,6 +24,7 @@ dockerpty==0.4.1
 docopt==0.6.2
 exceptiongroup==1.2.0
 flaky==3.7.0
+flask==3.0.2
 greenlet==3.0.3
 grpcio==1.63.2
 idna==2.10

tox.ini

@@ -1008,6 +1008,7 @@ deps =
   -e {toxinidir}/instrumentation/opentelemetry-instrumentation-kafka-python
   -e {toxinidir}/instrumentation/opentelemetry-instrumentation-confluent-kafka
   -e {toxinidir}/instrumentation/opentelemetry-instrumentation-dbapi
+  -e {toxinidir}/instrumentation/opentelemetry-instrumentation-flask
   -e {toxinidir}/instrumentation/opentelemetry-instrumentation-mysql
   -e {toxinidir}/instrumentation/opentelemetry-instrumentation-mysqlclient
   -e {toxinidir}/instrumentation/opentelemetry-instrumentation-psycopg