fix falcon and flask

Author: samuelcolvin

instrumentation/opentelemetry-instrumentation-falcon/tests/test_falcon.py

@@ -490,26 +490,6 @@ def test_custom_request_header_added_in_server_span(self):
         for key, _ in not_expected.items():
             self.assertNotIn(key, span.attributes)
 
-    def test_repeated_request_header_added_in_server_span(self):
-        headers = [
-            ("Custom-Test-Header-1", "Test Value 1"),
-            ("Custom-Test-Header-1", "Test Value 2"),
-        ]
-        self.client().simulate_request(
-            method="GET", path="/hello", headers=headers
-        )
-        span = self.memory_exporter.get_finished_spans()[0]
-        assert span.status.is_ok
-
-        expected = {
-            "http.request.header.custom_test_header_1": (
-                "Test Value 1,Test Value 2",
-            ),
-        }
-
-        self.assertEqual(span.kind, trace.SpanKind.SERVER)
-        self.assertSpanHasAttributes(span, expected)
-
     def test_custom_request_header_not_added_in_internal_span(self):
         tracer = trace.get_tracer(__name__)
         with tracer.start_as_current_span("test", kind=trace.SpanKind.SERVER):

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

@@ -687,6 +687,22 @@ def test_repeat_custom_request_header_added_in_server_span(self):
         self.assertEqual(span.kind, trace.SpanKind.SERVER)
         self.assertSpanHasAttributes(span, expected)
 
+    def test_repeat_similar_custom_request_header_added_in_server_span(self):
+        headers = [
+            ("Custom-Test-Header-1", "Test Value 1"),
+            ("Custom-Test-Header_1", "Test Value 2"),
+        ]
+        resp = self.client.get("/hello/123", headers=headers)
+        self.assertEqual(200, resp.status_code)
+        span = self.memory_exporter.get_finished_spans()[0]
+        expected = {
+            "http.request.header.custom_test_header_1": (
+                "Test Value 1, Test Value 2",
+            ),
+        }
+        self.assertEqual(span.kind, trace.SpanKind.SERVER)
+        self.assertSpanHasAttributes(span, expected)
+
     def test_custom_request_header_not_added_in_internal_span(self):
         tracer = trace.get_tracer(__name__)
         with tracer.start_as_current_span("test", kind=trace.SpanKind.SERVER):

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

@@ -358,17 +358,11 @@ def collect_custom_request_headers_attributes(environ):
             OTEL_INSTRUMENTATION_HTTP_CAPTURE_HEADERS_SANITIZE_FIELDS
         )
     )
-    headers = {}
-
-    for key, val in environ.items():
-        if key.startswith(_CARRIER_KEY_PREFIX):
-            header_key = (
-                key[_CARRIER_KEY_PREFIX_LEN:].replace("_", "-").lower()
-            )
-            if header_key in headers:
-                headers[header_key] += "," + val
-            else:
-                headers[header_key] = val
+    headers = {
+        key[_CARRIER_KEY_PREFIX_LEN:].replace("_", "-"): val
+        for key, val in environ.items()
+        if key.startswith(_CARRIER_KEY_PREFIX)
+    }
 
     return sanitize.sanitize_header_values(
         headers,