feat(spans): Record flag evaluations as span attributes (#4280)

Flags evaluated within a span are appended to the span as attributes.

---------

Co-authored-by: Daniel Szoke <[email protected]>

Author: cmanallen

sentry_sdk/feature_flags.py

@@ -66,3 +66,7 @@ def add_feature_flag(flag, result):
     """
     flags = sentry_sdk.get_current_scope().flags
     flags.set(flag, result)
+
+    span = sentry_sdk.get_current_span()
+    if span:
+        span.set_flag(f"flag.evaluation.{flag}", result)

sentry_sdk/integrations/launchdarkly.py

@@ -1,6 +1,6 @@
 from typing import TYPE_CHECKING
-import sentry_sdk
 
+from sentry_sdk.feature_flags import add_feature_flag
 from sentry_sdk.integrations import DidNotEnable, Integration
 
 try:
@@ -53,8 +53,8 @@ def metadata(self):
     def after_evaluation(self, series_context, data, detail):
         # type: (EvaluationSeriesContext, dict[Any, Any], EvaluationDetail) -> dict[Any, Any]
         if isinstance(detail.value, bool):
-            flags = sentry_sdk.get_current_scope().flags
-            flags.set(series_context.key, detail.value)
+            add_feature_flag(series_context.key, detail.value)
+
         return data
 
     def before_evaluation(self, series_context, data):

sentry_sdk/integrations/openfeature.py

@@ -1,6 +1,6 @@
 from typing import TYPE_CHECKING
-import sentry_sdk
 
+from sentry_sdk.feature_flags import add_feature_flag
 from sentry_sdk.integrations import DidNotEnable, Integration
 
 try:
@@ -29,11 +29,9 @@ class OpenFeatureHook(Hook):
     def after(self, hook_context, details, hints):
         # type: (HookContext, FlagEvaluationDetails[bool], HookHints) -> None
         if isinstance(details.value, bool):
-            flags = sentry_sdk.get_current_scope().flags
-            flags.set(details.flag_key, details.value)
+            add_feature_flag(details.flag_key, details.value)
 
     def error(self, hook_context, exception, hints):
         # type: (HookContext, Exception, HookHints) -> None
         if isinstance(hook_context.default_value, bool):
-            flags = sentry_sdk.get_current_scope().flags
-            flags.set(hook_context.flag_key, hook_context.default_value)
+            add_feature_flag(hook_context.flag_key, hook_context.default_value)

sentry_sdk/integrations/unleash.py

@@ -1,7 +1,7 @@
 from functools import wraps
 from typing import Any
 
-import sentry_sdk
+from sentry_sdk.feature_flags import add_feature_flag
 from sentry_sdk.integrations import Integration, DidNotEnable
 
 try:
@@ -26,8 +26,7 @@ def sentry_is_enabled(self, feature, *args, **kwargs):
 
             # We have no way of knowing what type of unleash feature this is, so we have to treat
             # it as a boolean / toggle feature.
-            flags = sentry_sdk.get_current_scope().flags
-            flags.set(feature, enabled)
+            add_feature_flag(feature, enabled)
 
             return enabled
 

sentry_sdk/tracing.py

@@ -278,6 +278,8 @@ class Span:
         "scope",
         "origin",
         "name",
+        "_flags",
+        "_flags_capacity",
     )
 
     def __init__(
@@ -313,6 +315,8 @@ def __init__(
         self._tags = {}  # type: MutableMapping[str, str]
         self._data = {}  # type: Dict[str, Any]
         self._containing_transaction = containing_transaction
+        self._flags = {}  # type: Dict[str, bool]
+        self._flags_capacity = 10
 
         if hub is not None:
             warnings.warn(
@@ -597,6 +601,11 @@ def set_data(self, key, value):
         # type: (str, Any) -> None
         self._data[key] = value
 
+    def set_flag(self, flag, result):
+        # type: (str, bool) -> None
+        if len(self._flags) < self._flags_capacity:
+            self._flags[flag] = result
+
     def set_status(self, value):
         # type: (str) -> None
         self.status = value
@@ -700,7 +709,9 @@ def to_json(self):
         if tags:
             rv["tags"] = tags
 
-        data = self._data
+        data = {}
+        data.update(self._flags)
+        data.update(self._data)
         if data:
             rv["data"] = data
 

tests/integrations/launchdarkly/test_launchdarkly.py

@@ -12,6 +12,8 @@
 import sentry_sdk
 from sentry_sdk.integrations import DidNotEnable
 from sentry_sdk.integrations.launchdarkly import LaunchDarklyIntegration
+from sentry_sdk import start_span, start_transaction
+from tests.conftest import ApproxDict
 
 
 @pytest.mark.parametrize(
@@ -202,3 +204,42 @@ def test_launchdarkly_integration_did_not_enable(monkeypatch):
     monkeypatch.setattr(client, "is_initialized", lambda: False)
     with pytest.raises(DidNotEnable):
         LaunchDarklyIntegration(ld_client=client)
+
+
+@pytest.mark.parametrize(
+    "use_global_client",
+    (False, True),
+)
+def test_launchdarkly_span_integration(
+    sentry_init, use_global_client, capture_events, uninstall_integration
+):
+    td = TestData.data_source()
+    td.update(td.flag("hello").variation_for_all(True))
+    # Disable background requests as we aren't using a server.
+    config = Config(
+        "sdk-key", update_processor_class=td, diagnostic_opt_out=True, send_events=False
+    )
+
+    uninstall_integration(LaunchDarklyIntegration.identifier)
+    if use_global_client:
+        ldclient.set_config(config)
+        sentry_init(traces_sample_rate=1.0, integrations=[LaunchDarklyIntegration()])
+        client = ldclient.get()
+    else:
+        client = LDClient(config=config)
+        sentry_init(
+            traces_sample_rate=1.0,
+            integrations=[LaunchDarklyIntegration(ld_client=client)],
+        )
+
+    events = capture_events()
+
+    with start_transaction(name="hi"):
+        with start_span(op="foo", name="bar"):
+            client.variation("hello", Context.create("my-org", "organization"), False)
+            client.variation("other", Context.create("my-org", "organization"), False)
+
+    (event,) = events
+    assert event["spans"][0]["data"] == ApproxDict(
+        {"flag.evaluation.hello": True, "flag.evaluation.other": False}
+    )

tests/integrations/openfeature/test_openfeature.py

@@ -7,7 +7,9 @@
 from openfeature.provider.in_memory_provider import InMemoryFlag, InMemoryProvider
 
 import sentry_sdk
+from sentry_sdk import start_span, start_transaction
 from sentry_sdk.integrations.openfeature import OpenFeatureIntegration
+from tests.conftest import ApproxDict
 
 
 def test_openfeature_integration(sentry_init, capture_events, uninstall_integration):
@@ -151,3 +153,27 @@ async def runner():
             {"flag": "world", "result": False},
         ]
     }
+
+
+def test_openfeature_span_integration(
+    sentry_init, capture_events, uninstall_integration
+):
+    uninstall_integration(OpenFeatureIntegration.identifier)
+    sentry_init(traces_sample_rate=1.0, integrations=[OpenFeatureIntegration()])
+
+    api.set_provider(
+        InMemoryProvider({"hello": InMemoryFlag("on", {"on": True, "off": False})})
+    )
+    client = api.get_client()
+
+    events = capture_events()
+
+    with start_transaction(name="hi"):
+        with start_span(op="foo", name="bar"):
+            client.get_boolean_value("hello", default_value=False)
+            client.get_boolean_value("world", default_value=False)
+
+    (event,) = events
+    assert event["spans"][0]["data"] == ApproxDict(
+        {"flag.evaluation.hello": True, "flag.evaluation.world": False}
+    )

tests/integrations/statsig/test_statsig.py

@@ -5,6 +5,8 @@
 from statsig.statsig_user import StatsigUser
 from random import random
 from unittest.mock import Mock
+from sentry_sdk import start_span, start_transaction
+from tests.conftest import ApproxDict
 
 import pytest
 
@@ -181,3 +183,21 @@ def test_wrapper_attributes(sentry_init, uninstall_integration):
 
     # Clean up
     statsig.check_gate = original_check_gate
+
+
+def test_statsig_span_integration(sentry_init, capture_events, uninstall_integration):
+    uninstall_integration(StatsigIntegration.identifier)
+
+    with mock_statsig({"hello": True}):
+        sentry_init(traces_sample_rate=1.0, integrations=[StatsigIntegration()])
+        events = capture_events()
+        user = StatsigUser(user_id="user-id")
+        with start_transaction(name="hi"):
+            with start_span(op="foo", name="bar"):
+                statsig.check_gate(user, "hello")
+                statsig.check_gate(user, "world")
+
+    (event,) = events
+    assert event["spans"][0]["data"] == ApproxDict(
+        {"flag.evaluation.hello": True, "flag.evaluation.world": False}
+    )

tests/integrations/unleash/test_unleash.py

@@ -8,7 +8,9 @@
 
 import sentry_sdk
 from sentry_sdk.integrations.unleash import UnleashIntegration
+from sentry_sdk import start_span, start_transaction
 from tests.integrations.unleash.testutils import mock_unleash_client
+from tests.conftest import ApproxDict
 
 
 def test_is_enabled(sentry_init, capture_events, uninstall_integration):
@@ -164,3 +166,21 @@ def test_wrapper_attributes(sentry_init, uninstall_integration):
         # Mock clients methods have not lost their qualified names after decoration.
         assert client.is_enabled.__name__ == "is_enabled"
         assert client.is_enabled.__qualname__ == original_is_enabled.__qualname__
+
+
+def test_unleash_span_integration(sentry_init, capture_events, uninstall_integration):
+    uninstall_integration(UnleashIntegration.identifier)
+
+    with mock_unleash_client():
+        sentry_init(traces_sample_rate=1.0, integrations=[UnleashIntegration()])
+        events = capture_events()
+        client = UnleashClient()  # type: ignore[arg-type]
+        with start_transaction(name="hi"):
+            with start_span(op="foo", name="bar"):
+                client.is_enabled("hello")
+                client.is_enabled("other")
+
+    (event,) = events
+    assert event["spans"][0]["data"] == ApproxDict(
+        {"flag.evaluation.hello": True, "flag.evaluation.other": False}
+    )

tests/test_feature_flags.py

@@ -7,6 +7,8 @@
 
 import sentry_sdk
 from sentry_sdk.feature_flags import add_feature_flag, FlagBuffer
+from sentry_sdk import start_span, start_transaction
+from tests.conftest import ApproxDict
 
 
 def test_featureflags_integration(sentry_init, capture_events, uninstall_integration):
@@ -220,3 +222,40 @@ def reader():
     # shared resource. When deepcopying we should have exclusive access to the underlying
     # memory.
     assert error_occurred is False
+
+
+def test_flag_limit(sentry_init, capture_events):
+    sentry_init(traces_sample_rate=1.0)
+
+    events = capture_events()
+
+    with start_transaction(name="hi"):
+        with start_span(op="foo", name="bar"):
+            add_feature_flag("0", True)
+            add_feature_flag("1", True)
+            add_feature_flag("2", True)
+            add_feature_flag("3", True)
+            add_feature_flag("4", True)
+            add_feature_flag("5", True)
+            add_feature_flag("6", True)
+            add_feature_flag("7", True)
+            add_feature_flag("8", True)
+            add_feature_flag("9", True)
+            add_feature_flag("10", True)
+
+    (event,) = events
+    assert event["spans"][0]["data"] == ApproxDict(
+        {
+            "flag.evaluation.0": True,
+            "flag.evaluation.1": True,
+            "flag.evaluation.2": True,
+            "flag.evaluation.3": True,
+            "flag.evaluation.4": True,
+            "flag.evaluation.5": True,
+            "flag.evaluation.6": True,
+            "flag.evaluation.7": True,
+            "flag.evaluation.8": True,
+            "flag.evaluation.9": True,
+        }
+    )
+    assert "flag.evaluation.10" not in event["spans"][0]["data"]