Add test for cog stream draining file logging

* This tests exposes the issue that cog stream
drainer can’t drain due to file logging in the
logging module.

test-integration/test_integration/fixtures/file-logging-stream-drain-project/cog.yaml

@@ -0,0 +1,5 @@
+build:
+  python_version: "3.11"
+  python_packages:
+    - "pillow==8.3.2"
+predict: "predict.py:Predictor"

test-integration/test_integration/fixtures/file-logging-stream-drain-project/predict.py

@@ -0,0 +1,22 @@
+from cog import BasePredictor, File
+import logging
+import os
+from PIL import Image
+
+
+class Predictor(BasePredictor):
+    def setup(self):
+        logFormatter = logging.Formatter("%(asctime)s [%(threadName)-12.12s] [%(levelname)-5.5s]  %(message)s")
+        rootLogger = logging.getLogger()
+
+        fileHandler = logging.FileHandler("{0}/{1}.log".format(os.path.dirname(__file__), "mylog.log"))
+        fileHandler.setFormatter(logFormatter)
+        rootLogger.addHandler(fileHandler)
+
+        consoleHandler = logging.StreamHandler()
+        consoleHandler.setFormatter(logFormatter)
+        rootLogger.addHandler(consoleHandler)
+
+    def predict(self) -> list[Image]:
+        logging.info("Do some logging.")
+        return []

test-integration/test_integration/test_predict.py

@@ -322,3 +322,19 @@ def test_predict_with_subprocess_in_setup(fixture_name):
             assert response.status_code == 200, str(response)
 
         assert busy_count < 10
+
+
+def test_file_logging_stream_drain(tmpdir_factory):
+    project_dir = Path(__file__).parent / "fixtures/file-logging-stream-drain-project"
+    out_dir = pathlib.Path(tmpdir_factory.mktemp("project"))
+    shutil.copytree(project_dir, out_dir, dirs_exist_ok=True)
+    cmd = ["cog", "--debug", "predict"]
+
+    subprocess.run(
+        cmd,
+        cwd=out_dir,
+        check=True,
+        capture_output=True,
+        text=True,
+        timeout=DEFAULT_TIMEOUT,
+    )