send http.route attribute in flask metric

CHANGELOG.md

@@ -47,6 +47,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- `opentelemetry-instrumentation-flask` Add http route to metric attributes
+  ([#2506](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2506))
+- 
 - `opentelemetry-sdk-extension-aws` Register AWS resource detectors under the
   `opentelemetry_resource_detector` entry point
   ([#2382](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2382))

instrumentation/opentelemetry-instrumentation-flask/src/opentelemetry/instrumentation/flask/__init__.py

@@ -284,6 +284,7 @@ def response_hook(span: Span, status: str, response_headers: List):
 _ENVIRON_ACTIVATION_KEY = "opentelemetry-flask.activation_key"
 _ENVIRON_REQCTX_REF_KEY = "opentelemetry-flask.reqctx_ref_key"
 _ENVIRON_TOKEN = "opentelemetry-flask.token"
+_ENVIRON_REQUEST_ROUTE_KEY = "request-route_key"
 
 _excluded_urls_from_env = get_excluded_urls("FLASK")
 
@@ -346,6 +347,11 @@ def _start_response(status, response_headers, *args, **kwargs):
                 excluded_urls is None
                 or not excluded_urls.url_disabled(flask.request.url)
             ):
+                if flask.request.url_rule:
+                    wrapped_app_environ[_ENVIRON_REQUEST_ROUTE_KEY] = str(
+                        flask.request.url_rule
+                    )
+
                 span = flask.request.environ.get(_ENVIRON_SPAN_KEY)
 
                 propagator = get_global_response_propagator()
@@ -388,13 +394,25 @@ def _start_response(status, response_headers, *args, **kwargs):
             duration_attrs_old = otel_wsgi._parse_duration_attrs(
                 attributes, _HTTPStabilityMode.DEFAULT
             )
+
+            if wrapped_app_environ.get(_ENVIRON_REQUEST_ROUTE_KEY, None):
+                duration_attrs_old[SpanAttributes.HTTP_ROUTE] = (
+                    wrapped_app_environ.get(_ENVIRON_REQUEST_ROUTE_KEY)
+                )
+
             duration_histogram_old.record(
                 max(round(duration_s * 1000), 0), duration_attrs_old
             )
         if duration_histogram_new:
             duration_attrs_new = otel_wsgi._parse_duration_attrs(
                 attributes, _HTTPStabilityMode.HTTP
             )
+
+            if wrapped_app_environ.get(_ENVIRON_REQUEST_ROUTE_KEY, None):
+                duration_attrs_new[SpanAttributes.HTTP_ROUTE] = (
+                    wrapped_app_environ.get(_ENVIRON_REQUEST_ROUTE_KEY)
+                )
+
             duration_histogram_new.record(
                 max(duration_s, 0), duration_attrs_new
             )

instrumentation/opentelemetry-instrumentation-flask/tests/test_programmatic.py

@@ -459,6 +459,7 @@ def test_exclude_lists_from_explicit(self):
         self.assertEqual(len(span_list), 1)
 
     def test_flask_metrics(self):
+        _server_duration_attrs_old.append("http.route")
         start = default_timer()
         self.client.get("/hello/123")
         self.client.get("/hello/321")
@@ -570,6 +571,7 @@ def test_basic_metric_success(self):
         self.client.get("/hello/756")
         expected_duration_attributes = {
             "http.method": "GET",
+            "http.route": "/hello/<int:helloid>",
             "http.host": "localhost",
             "http.scheme": "http",
             "http.flavor": "1.1",
@@ -597,6 +599,7 @@ def test_basic_metric_success_new_semconv(self):
         expected_duration_attributes = {
             "http.request.method": "GET",
             "url.scheme": "http",
+            "http.route": "/hello/<int:helloid>",
             "network.protocol.version": "1.1",
             "http.response.status_code": 200,
         }