Adding basic metrics support for recommendation service (Python)

CHANGELOG.md

@@ -111,3 +111,5 @@ significant modifications will be credited to OpenTelemetry Authors.
 ([#409](https://github.com/open-telemetry/opentelemetry-demo/pull/409))
 * Added hero scenario metric to Checkout Service on cache leak
 ([#339](https://github.com/open-telemetry/opentelemetry-demo/pull/339))
+* Added basic metrics support for recommendation service (Python)
+([#416](https://github.com/open-telemetry/opentelemetry-demo/pull/416))

docker-compose.yml

@@ -329,6 +329,9 @@ services:
       - PRODUCT_CATALOG_SERVICE_ADDR
       - OTEL_PYTHON_LOG_CORRELATION=true
       - OTEL_EXPORTER_OTLP_TRACES_ENDPOINT
+      # OTEL_EXPORTER_OTLP_METRICS_ENDPOINT # Not working for Python OTLP exporter
+      - OTEL_EXPORTER_OTLP_ENDPOINT
+      - OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE
       - OTEL_SERVICE_NAME=recommendationservice
       - PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python
     logging: *logging

docs/metric_service_features.md

@@ -17,5 +17,5 @@ Emoji Legend
 | Frontend        | JavaScript      | :construction:       | :construction:         | :construction:                        | :construction: | :construction: | :construction:                     |
 | Payment         | JavaScript      | :construction:       | :construction:         | :construction:                        | :construction: | :construction: | :construction:                     |
 | Product Catalog | Go              | :construction:       | :construction:         | :construction:                        | :construction: | :construction: | :construction:                     |
-| Recommendation  | Python          | :construction:       | :construction:         | :construction:                        | :construction: | :construction: | :construction:                     |
+| Recommendation  | Python          | :construction:       | :100:                  | :construction:                        | :construction: | :construction: | :construction:                     |
 | Shipping        | Rust            | :construction:       | :construction:         | :construction:                        | :construction: | :construction: | :construction:                     |

src/recommendationservice/recommendation_server.py

@@ -22,11 +22,19 @@
 
 # Pip
 import grpc
+
+# Traces
 from opentelemetry import trace
 from opentelemetry.sdk.trace import TracerProvider
 from opentelemetry.sdk.trace.export import (BatchSpanProcessor)
 from opentelemetry.exporter.otlp.proto.grpc.trace_exporter import OTLPSpanExporter
 
+# Metrics
+from opentelemetry import metrics
+from opentelemetry.sdk.metrics import MeterProvider
+from opentelemetry.sdk.metrics.export import (PeriodicExportingMetricReader)
+from opentelemetry.exporter.otlp.proto.grpc.metric_exporter import OTLPMetricExporter
+
 # Local
 import demo_pb2
 import demo_pb2_grpc
@@ -41,6 +49,8 @@ def ListRecommendations(self, request, context):
         span = trace.get_current_span()
         span.set_attribute("app.products_recommended.count", len(prod_list))
         logger.info("[Recv ListRecommendations] product_ids={}".format(prod_list))
+        app_recommendations_counter.add(len(prod_list), {'recommendation.type': 'catalog'})
+
         # build and return response
         response = demo_pb2.ListRecommendationsResponse()
         response.product_ids.extend(prod_list)
@@ -88,28 +98,42 @@ def must_map_env(key: str):
     return value
 
 if __name__ == "__main__":
-    logger = getJSONLogger('recommendationservice-server')
+    # Initialize tracer provider
     tracer_provider = TracerProvider()
     trace.set_tracer_provider(tracer_provider)
     tracer_provider.add_span_processor(BatchSpanProcessor(OTLPSpanExporter()))
     tracer = trace.get_tracer("recommendationservice")
 
+    # Initialize meter provider
+    metric_reader = PeriodicExportingMetricReader(OTLPMetricExporter())
+    provider = MeterProvider(metric_readers=[metric_reader])
+    metrics.set_meter_provider(provider)
+    meter = metrics.get_meter(__name__)
+
+    # Create counters
+    app_recommendations_counter = meter.create_counter(
+        'app.recommendations.counter', unit='recommendations', description="Counts the total number of given recommendations"
+    )
+
     port = must_map_env('RECOMMENDATION_SERVICE_PORT')
     catalog_addr = must_map_env('PRODUCT_CATALOG_SERVICE_ADDR')
 
     channel = grpc.insecure_channel(catalog_addr)
     product_catalog_stub = demo_pb2_grpc.ProductCatalogServiceStub(channel)
 
-    # create gRPC server
+    # Create gRPC server
     server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
 
-    # add class to gRPC server
+    # Add class to gRPC server
     service = RecommendationService()
     demo_pb2_grpc.add_RecommendationServiceServicer_to_server(service, server)
     health_pb2_grpc.add_HealthServicer_to_server(service, server)
 
-    # start server
+    # Start logger
+    logger = getJSONLogger('recommendationservice-server')
     logger.info("RecommendationService listening on port: " + port)
+
+    # Start server
     server.add_insecure_port('[::]:' + port)
     server.start()
     server.wait_for_termination()

src/recommendationservice/requirements.txt

@@ -1,12 +1,12 @@
 google-api-core==2.4.0
 grpcio-health-checking==1.43.0
 grpcio==1.43.0
-opentelemetry-api==1.9.1
-opentelemetry-exporter-otlp-proto-grpc==1.9.1
-opentelemetry-instrumentation==0.28b1
-opentelemetry-instrumentation-grpc==0.28b1
-opentelemetry-instrumentation-urllib3==0.28b1
-opentelemetry-sdk==1.9.1
+opentelemetry-api==1.13.0
+opentelemetry-exporter-otlp-proto-grpc==1.13.0
+opentelemetry-instrumentation==0.34b0
+opentelemetry-instrumentation-grpc==0.34b0
+opentelemetry-instrumentation-urllib3==0.34b0
+opentelemetry-sdk==1.13.0
 python-dotenv==0.20.0
 python-json-logger==2.0.2
 requests==2.27.1