Allow _DjangoMiddleware to have span creation overridden

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+- `opentelemetry-instrumentation-django`: Add `_DjangoMiddleware._get_span` for easier customization ([#3652](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3652))
+
 ### Fixed
 
 - `opentelemetry-instrumentation`: Fix dependency conflict detection when instrumented packages are not installed by moving check back to before instrumentors are loaded. Add "instruments-any" feature for instrumentations that target multiple packages.

instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware/otel_middleware.py

@@ -13,15 +13,17 @@
 # limitations under the License.
 
 import types
+from contextvars import Token
 from logging import getLogger
 from time import time
 from timeit import default_timer
-from typing import Callable
+from typing import Callable, ContextManager, Union
 
 from django import VERSION as django_version
 from django.http import HttpRequest, HttpResponse
 
 from opentelemetry.context import detach
+from opentelemetry.context.context import Context
 from opentelemetry.instrumentation._semconv import (
     _filter_semconv_active_request_count_attr,
     _filter_semconv_duration_attrs,
@@ -207,26 +209,17 @@ def process_request(self, request):
 
         if is_asgi_request:
             carrier = request.scope
-            carrier_getter = asgi_getter
             collect_request_attributes = asgi_collect_request_attributes
         else:
             carrier = request_meta
-            carrier_getter = wsgi_getter
             collect_request_attributes = wsgi_collect_request_attributes
 
         attributes = collect_request_attributes(
             carrier,
             self._sem_conv_opt_in_mode,
         )
-        span, token = _start_internal_or_server_span(
-            tracer=self._tracer,
-            span_name=self._get_span_name(request),
-            start_time=request_meta.get(
-                "opentelemetry-instrumentor-django.starttime_key"
-            ),
-            context_carrier=carrier,
-            context_getter=carrier_getter,
-            attributes=attributes,
+        span, token, activation = self._get_span(
+            request, attributes, is_asgi_request
         )
 
         active_requests_count_attrs = _parse_active_request_count_attrs(
@@ -282,8 +275,6 @@ def process_request(self, request):
             for key, value in attributes.items():
                 span.set_attribute(key, value)
 
-        activation = use_span(span, end_on_exit=True)
-        activation.__enter__()  # pylint: disable=E1101
         request_start_time = default_timer()
         request.META[self._environ_timer_key] = request_start_time
         request.META[self._environ_activation_key] = activation
@@ -301,6 +292,37 @@ def process_request(self, request):
                 # would not be called. Log the exception instead.
                 _logger.exception("Exception raised by request_hook")
 
+    def _get_span(
+        self,
+        request: Union[HttpRequest, ASGIRequest],
+        attributes: dict,
+        is_asgi_request: bool,
+    ) -> tuple[Span, Token[Context], ContextManager]:
+        request_meta = request.META
+
+        if is_asgi_request:
+            carrier = request.scope
+            carrier_getter = asgi_getter
+        else:
+            carrier = request_meta
+            carrier_getter = wsgi_getter
+
+        span, token = _start_internal_or_server_span(
+            tracer=self._tracer,
+            span_name=self._get_span_name(request),
+            start_time=request_meta.get(
+                "opentelemetry-instrumentor-django.starttime_key"
+            ),
+            context_carrier=carrier,
+            context_getter=carrier_getter,
+            attributes=attributes,
+        )
+
+        activation = use_span(span, end_on_exit=True)
+        activation.__enter__()  # pylint: disable=E1101
+
+        return span, token, activation
+
     # pylint: disable=unused-argument
     def process_view(self, request, view_func, *args, **kwargs):
         # Process view is executed before the view function, here we get the

opentelemetry-instrumentation/src/opentelemetry/instrumentation/utils.py

@@ -16,6 +16,7 @@
 
 import urllib.parse
 from contextlib import contextmanager
+from contextvars import Token
 from importlib import import_module
 from re import escape, sub
 from typing import Any, Dict, Generator, Sequence
@@ -30,10 +31,11 @@
     _SUPPRESS_HTTP_INSTRUMENTATION_KEY,
     _SUPPRESS_INSTRUMENTATION_KEY,
 )
+from opentelemetry.context.context import Context
 
 # pylint: disable=E0611
 from opentelemetry.propagate import extract
-from opentelemetry.trace import StatusCode
+from opentelemetry.trace import Span, StatusCode
 from opentelemetry.trace.propagation.tracecontext import (
     TraceContextTextMapPropagator,
 )
@@ -119,7 +121,7 @@ def _start_internal_or_server_span(
     context_carrier,
     context_getter,
     attributes=None,
-):
+) -> tuple[Span, Token[Context]]:
     """Returns internal or server span along with the token which can be used by caller to reset context
 
 
@@ -136,13 +138,13 @@ def _start_internal_or_server_span(
             from carrier.
     """
 
-    token = ctx = span_kind = None
     if trace.get_current_span() is trace.INVALID_SPAN:
         ctx = extract(context_carrier, getter=context_getter)
         token = context.attach(ctx)
         span_kind = trace.SpanKind.SERVER
     else:
         ctx = context.get_current()
+        token = None
         span_kind = trace.SpanKind.INTERNAL
     span = tracer.start_span(
         name=span_name,