feat: initialize SCA reachability in the Lambda wrapper

Author: florentinl

datadog_lambda/wrapper.py

@@ -67,6 +67,18 @@
 
     start()
 
+if config.sca_enabled:
+    try:
+        from ddtrace.internal.sca.product import start as start_sca
+        from ddtrace.internal.sca.product import post_preload as instrument_sca
+
+        # The layer patches integrations before loading the wrapper. It does not
+        # use ddtrace.auto, so run both SCA startup phases before importing user code.
+        start_sca()
+        instrument_sca()
+    except Exception:
+        logger.debug("Failed to initialize SCA reachability", exc_info=True)
+
 profiler = None
 if config.profiling_enabled:
     try:

tests/test_wrapper.py

@@ -23,6 +23,38 @@
 MAX_UINT_64BITS = (1 << 64) - 1
 
 
+@pytest.mark.parametrize("sca_enabled", [False, True])
+def test_sca_startup(sca_enabled, monkeypatch):
+    product = MagicMock()
+    monkeypatch.setattr("datadog_lambda.config.Config.sca_enabled", sca_enabled)
+    monkeypatch.setitem(sys.modules, "ddtrace.internal.sca.product", product)
+
+    importlib.reload(wrapper)
+
+    assert product.mock_calls == (
+        [call.start(), call.post_preload()] if sca_enabled else []
+    )
+
+
+def test_sca_startup_with_older_tracer(monkeypatch):
+    monkeypatch.setattr("datadog_lambda.config.Config.sca_enabled", True)
+    monkeypatch.setitem(sys.modules, "ddtrace.internal.sca.product", None)
+
+    importlib.reload(wrapper)
+
+
+def test_sca_startup_failure_preserves_handler(monkeypatch):
+    product = MagicMock()
+    product.start.side_effect = RuntimeError("SCA startup failed")
+    monkeypatch.setattr("datadog_lambda.config.Config.sca_enabled", True)
+    monkeypatch.setitem(sys.modules, "ddtrace.internal.sca.product", product)
+
+    importlib.reload(wrapper)
+
+    product.post_preload.assert_not_called()
+    assert callable(wrapper.datadog_lambda_wrapper)
+
+
 class TestDatadogLambdaWrapper(unittest.TestCase):
     def setUp(self):
         # Force @datadog_lambda_wrapper to always create a real