test

Author: sentrivana

sentry_sdk/scope.py

@@ -1043,7 +1043,9 @@ def start_transaction(
         sampling_context.update(custom_sampling_context)
         transaction._set_initial_sampling_decision(sampling_context=sampling_context)
 
-        # update the sample rate in the dsc
+        # update the sample rate in the dsc. the baggage should be immutable
+        # at this point, but in order to not have broken traces we make
+        # an exception here
         propagation_context = self.get_active_propagation_context()
         if propagation_context:
             dsc = propagation_context.dynamic_sampling_context

sentry_sdk/tracing.py

@@ -1061,7 +1061,6 @@ def get_baggage(self):
 
         The first time a new baggage with Sentry items is made,
         it will be frozen."""
-
         if not self._baggage or self._baggage.mutable:
             self._baggage = Baggage.populate_from_transaction(self)
 

tests/test_dsc.py

@@ -8,6 +8,9 @@
 This is not tested in this file.
 """
 
+import random
+from unittest import mock
+
 import pytest
 
 import sentry_sdk
@@ -134,6 +137,82 @@ def test_dsc_continuation_of_trace(sentry_init, capture_envelopes):
     assert envelope_trace_header["transaction"] == "bar"
 
 
+def test_dsc_continuation_of_trace_sample_rate_changed(sentry_init, capture_envelopes):
+    """
+    Another service calls our service and passes tracing information to us.
+    Our service is continuing the trace, but modifies the sample rate.
+    The DSC propagated further should contain the updated sample rate.
+    """
+
+    def my_traces_sampler(sampling_context):
+        return 0.25
+
+    sentry_init(
+        dsn="https://[email protected]/12312012",
+        release="[email protected]",
+        environment="canary",
+        traces_sampler=my_traces_sampler,
+    )
+    envelopes = capture_envelopes()
+
+    # This is what the upstream service sends us
+    sentry_trace = "771a43a4192642f0b136d5159a501700-1234567890abcdef-1"
+    baggage = (
+        "other-vendor-value-1=foo;bar;baz, "
+        "sentry-trace_id=771a43a4192642f0b136d5159a501700, "
+        "sentry-public_key=frontendpublickey, "
+        "sentry-sample_rate=1.0, "
+        "sentry-sampled=true, "
+        "[email protected], "
+        "sentry-environment=bird, "
+        "sentry-transaction=bar, "
+        "other-vendor-value-2=foo;bar;"
+    )
+    incoming_http_headers = {
+        "HTTP_SENTRY_TRACE": sentry_trace,
+        "HTTP_BAGGAGE": baggage,
+    }
+
+    # We continue the incoming trace and start a new transaction
+    with mock.patch.object(random, "random", return_value=0.2):
+        transaction = sentry_sdk.continue_trace(incoming_http_headers)
+        with sentry_sdk.start_transaction(transaction, name="foo"):
+            pass
+
+    assert len(envelopes) == 1
+
+    transaction_envelope = envelopes[0]
+    envelope_trace_header = transaction_envelope.headers["trace"]
+
+    assert "trace_id" in envelope_trace_header
+    assert type(envelope_trace_header["trace_id"]) == str
+    assert envelope_trace_header["trace_id"] == "771a43a4192642f0b136d5159a501700"
+
+    assert "public_key" in envelope_trace_header
+    assert type(envelope_trace_header["public_key"]) == str
+    assert envelope_trace_header["public_key"] == "frontendpublickey"
+
+    assert "sample_rate" in envelope_trace_header
+    assert type(envelope_trace_header["sample_rate"]) == str
+    assert envelope_trace_header["sample_rate"] == "0.25"
+
+    assert "sampled" in envelope_trace_header
+    assert type(envelope_trace_header["sampled"]) == str
+    assert envelope_trace_header["sampled"] == "true"
+
+    assert "release" in envelope_trace_header
+    assert type(envelope_trace_header["release"]) == str
+    assert envelope_trace_header["release"] == "[email protected]"
+
+    assert "environment" in envelope_trace_header
+    assert type(envelope_trace_header["environment"]) == str
+    assert envelope_trace_header["environment"] == "bird"
+
+    assert "transaction" in envelope_trace_header
+    assert type(envelope_trace_header["transaction"]) == str
+    assert envelope_trace_header["transaction"] == "bar"
+
+
 def test_dsc_issue(sentry_init, capture_envelopes):
     """
     Our service is a standalone service that does not have tracing enabled. Just uses Sentry for error reporting.