Make sure filedir is at the beginning of PYTHONPATH

opentelemetry-auto-instrumentation/src/opentelemetry/auto_instrumentation/auto_instrumentation.py

@@ -25,11 +25,17 @@
 
 def run() -> None:
 
-    python_path = environ.get("PYTHONPATH", "")
+    python_path = environ.get("PYTHONPATH", [])
+
+    if python_path:
+        python_path = python_path.split(pathsep)
+
     filedir_path = dirname(abspath(__file__))
 
-    if filedir_path not in python_path:
-        environ["PYTHONPATH"] = pathsep.join([filedir_path, python_path])
+    if filedir_path in python_path:
+        python_path.remove(filedir_path)
+
+    environ["PYTHONPATH"] = pathsep.join([filedir_path, *python_path])
 
     executable = which(argv[1])
 

opentelemetry-auto-instrumentation/tests/test_instrumentor.py

@@ -14,8 +14,12 @@
 # type: ignore
 
 from logging import WARNING
+from os import environ
+from os.path import abspath, dirname, pathsep
 from unittest import TestCase
+from unittest.mock import patch
 
+from opentelemetry.auto_instrumentation import auto_instrumentation
 from opentelemetry.auto_instrumentation.instrumentor import BaseInstrumentor
 
 
@@ -44,3 +48,41 @@ def test_protect(self):
 
     def test_singleton(self):
         self.assertIs(self.Instrumentor(), self.Instrumentor())
+
+
+class TestRun(TestCase):
+    auto_instrumentation_path = dirname(abspath(auto_instrumentation.__file__))
+
+    @patch.dict("os.environ", {"PYTHONPATH": ""})
+    @patch("opentelemetry.auto_instrumentation.auto_instrumentation.argv")
+    @patch("opentelemetry.auto_instrumentation.auto_instrumentation.execl")
+    def test_run_empty(
+        self, mock_execl, mock_argv
+    ):  # pylint: disable=unused-argument
+        auto_instrumentation.run()
+        assert environ["PYTHONPATH"] == self.auto_instrumentation_path
+
+    @patch.dict("os.environ", {"PYTHONPATH": "abc"})
+    @patch("opentelemetry.auto_instrumentation.auto_instrumentation.argv")
+    @patch("opentelemetry.auto_instrumentation.auto_instrumentation.execl")
+    def test_run_non_empty(
+        self, mock_execl, mock_argv
+    ):  # pylint: disable=unused-argument
+        auto_instrumentation.run()
+        assert environ["PYTHONPATH"] == pathsep.join(
+            [self.auto_instrumentation_path, "abc"]
+        )
+
+    @patch.dict(
+        "os.environ",
+        {"PYTHONPATH": pathsep.join(["abc", auto_instrumentation_path])},
+    )
+    @patch("opentelemetry.auto_instrumentation.auto_instrumentation.argv")
+    @patch("opentelemetry.auto_instrumentation.auto_instrumentation.execl")
+    def test_run_after_path(
+        self, mock_execl, mock_argv
+    ):  # pylint: disable=unused-argument
+        auto_instrumentation.run()
+        assert environ["PYTHONPATH"] == pathsep.join(
+            [self.auto_instrumentation_path, "abc"]
+        )