flask: add http.target and http.route to metric attributes

CHANGELOG.md

@@ -61,6 +61,8 @@ 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

@@ -266,11 +266,11 @@ def response_hook(span: Span, status: str, response_headers: List):
 )
 from opentelemetry.instrumentation.utils import _start_internal_or_server_span
 from opentelemetry.metrics import get_meter
+from opentelemetry.semconv.attributes.http_attributes import HTTP_ROUTE
 from opentelemetry.semconv.metrics import MetricInstruments
 from opentelemetry.semconv.metrics.http_metrics import (
     HTTP_SERVER_REQUEST_DURATION,
 )
-from opentelemetry.semconv.trace import SpanAttributes
 from opentelemetry.util.http import (
     get_excluded_urls,
     parse_excluded_urls,
@@ -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 = "opentelemetry-flask.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[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[HTTP_ROUTE] = wrapped_app_environ.get(
+                    _ENVIRON_REQUEST_ROUTE_KEY
+                )
+
             duration_histogram_new.record(
                 max(duration_s, 0), duration_attrs_new
             )
@@ -425,7 +443,7 @@ def _before_request():
         if flask.request.url_rule:
             # For 404 that result from no route found, etc, we
             # don't have a url_rule.
-            attributes[SpanAttributes.HTTP_ROUTE] = flask.request.url_rule.rule
+            attributes[HTTP_ROUTE] = flask.request.url_rule.rule
         span, token = _start_internal_or_server_span(
             tracer=tracer,
             span_name=span_name,

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

@@ -85,6 +85,9 @@ def expected_attributes_new(override_attributes):
     return default_attributes
 
 
+_server_duration_attrs_old_copy = _server_duration_attrs_old.copy()
+_server_duration_attrs_old_copy.append("http.route")
+
 _expected_metric_names_old = [
     "http.server.active_requests",
     "http.server.duration",
@@ -95,7 +98,7 @@ def expected_attributes_new(override_attributes):
 ]
 _recommended_metrics_attrs_old = {
     "http.server.active_requests": _server_active_requests_count_attrs_old,
-    "http.server.duration": _server_duration_attrs_old,
+    "http.server.duration": _server_duration_attrs_old_copy,
 }
 _recommended_metrics_attrs_new = {
     "http.server.active_requests": _server_active_requests_count_attrs_new,
@@ -109,7 +112,7 @@ def expected_attributes_new(override_attributes):
 )
 _recommended_metrics_attrs_both = {
     "http.server.active_requests": _server_active_requests_count_attrs_both,
-    "http.server.duration": _server_duration_attrs_old,
+    "http.server.duration": _server_duration_attrs_old_copy,
     "http.server.request.duration": _server_duration_attrs_new,
 }
 
@@ -570,6 +573,7 @@ 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 +601,7 @@ 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,
         }