Fix type of sample_rate in DSC (and add explanatory tests) (#3603)

In the DSC send in the envelope header for envelopes containing errors the type of sample_rate was float instead of the correct str type.

sentry_sdk/tracing_utils.py

@@ -532,7 +532,7 @@ def from_options(cls, scope):
             sentry_items["public_key"] = Dsn(options["dsn"]).public_key
 
         if options.get("traces_sample_rate"):
-            sentry_items["sample_rate"] = options["traces_sample_rate"]
+            sentry_items["sample_rate"] = str(options["traces_sample_rate"])
 
         return Baggage(sentry_items, third_party_items, mutable)
 

tests/test_dsc.py

@@ -0,0 +1,322 @@
+"""
+This tests test for the correctness of the dynamic sampling context (DSC) in the trace header of envelopes.
+
+The DSC is defined here:
+https://develop.sentry.dev/sdk/telemetry/traces/dynamic-sampling-context/#dsc-specification
+
+The DSC is propagated between service using a header called "baggage".
+This is not tested in this file.
+"""
+
+import pytest
+
+import sentry_sdk
+import sentry_sdk.client
+
+
+def test_dsc_head_of_trace(sentry_init, capture_envelopes):
+    """
+    Our service is the head of the trace (it starts a new trace)
+    and sends a transaction event to Sentry.
+    """
+    sentry_init(
+        dsn="https://[email protected]/12312012",
+        release="[email protected]",
+        environment="canary",
+        traces_sample_rate=1.0,
+    )
+    envelopes = capture_envelopes()
+
+    # We start a new transaction
+    with sentry_sdk.start_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 "public_key" in envelope_trace_header
+    assert type(envelope_trace_header["public_key"]) == str
+    assert envelope_trace_header["public_key"] == "mysecret"
+
+    assert "sample_rate" in envelope_trace_header
+    assert type(envelope_trace_header["sample_rate"]) == str
+    assert envelope_trace_header["sample_rate"] == "1.0"
+
+    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"] == "canary"
+
+    assert "transaction" in envelope_trace_header
+    assert type(envelope_trace_header["transaction"]) == str
+    assert envelope_trace_header["transaction"] == "foo"
+
+
+def test_dsc_continuation_of_trace(sentry_init, capture_envelopes):
+    """
+    Another service calls our service and passes tracing information to us.
+    Our service is continuing the trace and sends a transaction event to Sentry.
+    """
+    sentry_init(
+        dsn="https://[email protected]/12312012",
+        release="[email protected]",
+        environment="canary",
+        traces_sample_rate=1.0,
+    )
+    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=0.01337, "
+        "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
+    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"] == "0.01337"
+
+    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.
+    """
+    sentry_init(
+        dsn="https://[email protected]/12312012",
+        release="[email protected]",
+        environment="canary",
+    )
+    envelopes = capture_envelopes()
+
+    # No transaction is started, just an error is captured
+    try:
+        1 / 0
+    except ZeroDivisionError as exp:
+        sentry_sdk.capture_exception(exp)
+
+    assert len(envelopes) == 1
+
+    error_envelope = envelopes[0]
+
+    envelope_trace_header = error_envelope.headers["trace"]
+
+    assert "trace_id" in envelope_trace_header
+    assert type(envelope_trace_header["trace_id"]) == str
+
+    assert "public_key" in envelope_trace_header
+    assert type(envelope_trace_header["public_key"]) == str
+    assert envelope_trace_header["public_key"] == "mysecret"
+
+    assert "sample_rate" not in envelope_trace_header
+
+    assert "sampled" not in envelope_trace_header
+
+    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"] == "canary"
+
+    assert "transaction" not in envelope_trace_header
+
+
+def test_dsc_issue_with_tracing(sentry_init, capture_envelopes):
+    """
+    Our service has tracing enabled and an error occurs in an transaction.
+    Envelopes containing errors also have the same DSC than the transaction envelopes.
+    """
+    sentry_init(
+        dsn="https://[email protected]/12312012",
+        release="[email protected]",
+        environment="canary",
+        traces_sample_rate=1.0,
+    )
+    envelopes = capture_envelopes()
+
+    # We start a new transaction and an error occurs
+    with sentry_sdk.start_transaction(name="foo"):
+        try:
+            1 / 0
+        except ZeroDivisionError as exp:
+            sentry_sdk.capture_exception(exp)
+
+    assert len(envelopes) == 2
+
+    error_envelope, transaction_envelope = envelopes
+
+    assert error_envelope.headers["trace"] == transaction_envelope.headers["trace"]
+
+    envelope_trace_header = error_envelope.headers["trace"]
+
+    assert "trace_id" in envelope_trace_header
+    assert type(envelope_trace_header["trace_id"]) == str
+
+    assert "public_key" in envelope_trace_header
+    assert type(envelope_trace_header["public_key"]) == str
+    assert envelope_trace_header["public_key"] == "mysecret"
+
+    assert "sample_rate" in envelope_trace_header
+    assert envelope_trace_header["sample_rate"] == "1.0"
+    assert type(envelope_trace_header["sample_rate"]) == str
+
+    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"] == "canary"
+
+    assert "transaction" in envelope_trace_header
+    assert type(envelope_trace_header["transaction"]) == str
+    assert envelope_trace_header["transaction"] == "foo"
+
+
+@pytest.mark.parametrize(
+    "traces_sample_rate",
+    [
+        0,  # no traces will be started, but if incoming traces will be continued (by our instrumentations, not happening in this test)
+        None,  # no tracing at all. This service will never create transactions.
+    ],
+)
+def test_dsc_issue_twp(sentry_init, capture_envelopes, traces_sample_rate):
+    """
+    Our service does not have tracing enabled, but we receive tracing information from an upstream service.
+    Error envelopes still contain a DCS. This is called "tracing without performance" or TWP for short.
+
+    This way if I have three services A, B, and C, and A and C have tracing enabled, but B does not,
+    we still can see the full trace in Sentry, and associate errors send by service B to Sentry.
+    (This test would be service B in this scenario)
+    """
+    sentry_init(
+        dsn="https://[email protected]/12312012",
+        release="[email protected]",
+        environment="canary",
+        traces_sample_rate=traces_sample_rate,
+    )
+    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=0.01337, "
+        "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 trace (meaning: saving the incoming trace information on the scope)
+    # but in this test, we do not start a transaction.
+    sentry_sdk.continue_trace(incoming_http_headers)
+
+    # No transaction is started, just an error is captured
+    try:
+        1 / 0
+    except ZeroDivisionError as exp:
+        sentry_sdk.capture_exception(exp)
+
+    assert len(envelopes) == 1
+
+    error_envelope = envelopes[0]
+
+    envelope_trace_header = error_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"] == "0.01337"
+
+    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"