elastic · beniwohli · Feb 6, 2020 · Jan 31, 2020 · Feb 3, 2020 · Feb 4, 2020
diff --git a/CHANGELOG.asciidoc b/CHANGELOG.asciidoc
@@ -52,6 +52,11 @@ This will be the last minor release to support the following versions:
  * Use Span ID as parent ID in errors if an error happens inside a span {pull}669[#669]
  * Added experimental support for API Key authentication {pull}679[#679]
 
+[float]
+===== Bug fixes
+
+ * introduced workaround to avoid instrumenting twice in rare cases (#708)
+
 
 [[release-notes-5.x]]
 === Python Agent version 5.x

diff --git a/elasticapm/instrumentation/packages/base.py b/elasticapm/instrumentation/packages/base.py
@@ -38,6 +38,11 @@
 logger = get_logger("elasticapm.instrument")
 
 
+class ElasticAPMFunctionWrapper(wrapt.FunctionWrapper):
+    # used to differentiate between our own function wrappers and 1st/3rd party wrappers
+    pass
+
+
 class AbstractInstrumentedModule(object):
     """
     This class is designed to reduce the amount of code required to
@@ -136,8 +141,13 @@ def instrument(self):
                     # We jump through hoop here to get the original
                     # `module`/`method` in the call to `call_if_sampling`
                     parent, attribute, original = wrapt.resolve_path(module, method)
+                    if isinstance(original, ElasticAPMFunctionWrapper):
+                        logger.debug("%s.%s already instrumented, skipping", module, method)
+                        continue
                     self.originals[(module, method)] = original
-                    wrapper = wrapt.FunctionWrapper(original, functools.partial(self.call_if_sampling, module, method))
+                    wrapper = ElasticAPMFunctionWrapper(
+                        original, functools.partial(self.call_if_sampling, module, method)
+                    )
                     wrapt.apply_patch(parent, attribute, wrapper)
                     instrumented_methods.append((module, method))
                 except ImportError:

diff --git a/tests/instrumentation/base_tests.py b/tests/instrumentation/base_tests.py
@@ -37,6 +37,7 @@
 import pytest
 
 import elasticapm
+from elasticapm.conf import constants
 from elasticapm.conf.constants import SPAN
 from elasticapm.instrumentation.packages.base import AbstractInstrumentedModule
 from elasticapm.utils import compat, wrapt
@@ -65,7 +66,8 @@ class _TestDummyInstrumentation(AbstractInstrumentedModule):
     def call(self, module, method, wrapped, instance, args, kwargs):
         kwargs = kwargs or {}
         kwargs["call_args"] = (module, method)
-        return wrapped(*args, **kwargs)
+        with elasticapm.capture_span("dummy"):
+            return wrapped(*args, **kwargs)
 
 
 def test_instrument_nonexisting_method_on_module():
@@ -79,6 +81,25 @@ def test_instrument_nonexisting_method(caplog):
     assert "has no attribute" in record.message
 
 
+def test_double_instrument(elasticapm_client):
+    elasticapm_client.begin_transaction("test")
+    inst = _TestDummyInstrumentation()
+    try:
+        inst.instrument()
+        assert hasattr(Dummy.dummy, "_self_wrapper")
+        Dummy().dummy()
+        elasticapm_client.end_transaction()
+        assert len(elasticapm_client.spans_for_transaction(elasticapm_client.events[constants.TRANSACTION][0])) == 1
+        inst.instrumented = False
+        inst.instrument()
+        elasticapm_client.begin_transaction("test")
+        Dummy().dummy()
+        elasticapm_client.end_transaction()
+        assert len(elasticapm_client.spans_for_transaction(elasticapm_client.events[constants.TRANSACTION][1])) == 1
+    finally:
+        inst.uninstrument()
+
+
 @pytest.mark.skipif(compat.PY3, reason="different object model")
 def test_uninstrument_py2(caplog):
     assert isinstance(Dummy.dummy, types.MethodType)