Unpack custom_sampling_context into attributes in ASGI (#3764)

Author: sentrivana

MIGRATION_GUIDE.md

@@ -20,6 +20,7 @@ Looking to upgrade from Sentry SDK 2.x to 3.x? Here's a comprehensive list of wh
 - clickhouse-driver integration: The query is now available under the `db.query.text` span attribute (only if `send_default_pii` is `True`).
 - `sentry_sdk.init` now returns `None` instead of a context manager.
 - The `sampling_context` argument of `traces_sampler` now additionally contains all span attributes known at span start.
+- The `sampling_context` argument of `traces_sampler` doesn't contain the `asgi_scope` object anymore for ASGI frameworks. Instead, the individual properties, if available, are accessible as `asgi_scope.endpoint`, `asgi_scope.path`, `asgi_scope.root_path`, `asgi_scope.route`, `asgi_scope.scheme`, `asgi_scope.server` and `asgi_scope.type`.
 
 ### Removed
 

sentry_sdk/integrations/asgi.py

@@ -209,7 +209,7 @@ async def _run_app(self, scope, receive, send, asgi_version):
                                 name=transaction_name,
                                 source=transaction_source,
                                 origin=self.span_origin,
-                                custom_sampling_context={"asgi_scope": scope},
+                                attributes=_prepopulate_attributes(scope),
                             )
                             if should_trace
                             else nullcontext()
@@ -324,3 +324,16 @@ def _get_transaction_name_and_source(self, transaction_style, asgi_scope):
             return name, source
 
         return name, source
+
+
+def _prepopulate_attributes(scope):
+    # type: (Any) -> dict[str, Any]
+    """Unpack asgi_scope into serializable attributes."""
+    scope = scope or {}
+
+    attributes = {}
+    for attr in ("endpoint", "path", "root_path", "route", "scheme", "server", "type"):
+        if scope.get(attr):
+            attributes[f"asgi_scope.{attr}"] = scope[attr]
+
+    return attributes

sentry_sdk/integrations/opentelemetry/sampler.py

@@ -147,6 +147,7 @@ def should_sample(
                 "transaction_context": {
                     "name": name,
                     "op": attributes.get(SentrySpanAttribute.OP),
+                    "source": attributes.get(SentrySpanAttribute.SOURCE),
                 },
                 "parent_sampled": get_parent_sampled(parent_span_context, trace_id),
             }

sentry_sdk/tracing.py

@@ -1250,6 +1250,7 @@ def __init__(
                 # Prepopulate some attrs so that they're accessible in traces_sampler
                 attributes = attributes or {}
                 attributes[SentrySpanAttribute.OP] = op
+                attributes[SentrySpanAttribute.SOURCE] = source
                 if sampled is not None:
                     attributes[SentrySpanAttribute.CUSTOM_SAMPLED] = sampled
 
@@ -1260,7 +1261,6 @@ def __init__(
                 self.origin = origin or DEFAULT_SPAN_ORIGIN
                 self.description = description
                 self.name = span_name
-                self.source = source
 
                 if status is not None:
                     self.set_status(status)

tests/integrations/asgi/test_asgi.py

@@ -721,3 +721,20 @@ async def test_custom_transaction_name(
     assert transaction_event["type"] == "transaction"
     assert transaction_event["transaction"] == "foobar"
     assert transaction_event["transaction_info"] == {"source": "custom"}
+
+
+@pytest.mark.asyncio
+async def test_asgi_scope_in_traces_sampler(sentry_init, asgi3_app):
+    def dummy_traces_sampler(sampling_context):
+        assert sampling_context["asgi_scope.path"] == "/test"
+        assert sampling_context["asgi_scope.scheme"] == "http"
+
+    sentry_init(
+        traces_sampler=dummy_traces_sampler,
+        traces_sample_rate=1.0,
+    )
+
+    app = SentryAsgiMiddleware(asgi3_app)
+
+    async with TestClient(app) as client:
+        await client.get("/test")