direct all logging to stdout (not stderr)

src/prefect/agent/agent.py

@@ -1,6 +1,7 @@
 import ast
 import logging
 import signal
+import sys
 import time
 from contextlib import contextmanager
 from typing import Any, Callable, Generator, Iterable, Union
@@ -75,7 +76,7 @@ def __init__(self, name: str = None, labels: Iterable[str] = None) -> None:
 
         logger = logging.getLogger(self.name)
         logger.setLevel(config.cloud.agent.get("level"))
-        ch = logging.StreamHandler()
+        ch = logging.StreamHandler(sys.stdout)
         formatter = logging.Formatter(context.config.logging.format)
         formatter.converter = time.gmtime  # type: ignore
         ch.setFormatter(formatter)

src/prefect/agent/kubernetes/resource_manager.py

@@ -1,5 +1,6 @@
 import logging
 import os
+import sys
 import time
 from typing import TYPE_CHECKING
 
@@ -30,7 +31,7 @@ def __init__(self) -> None:
 
         logger = logging.getLogger("resource-manager")
         logger.setLevel(logging.DEBUG)
-        ch = logging.StreamHandler()
+        ch = logging.StreamHandler(sys.stdout)
         ch.setLevel(logging.DEBUG)
         formatter = logging.Formatter(context.config.logging.format)
         formatter.converter = time.gmtime  # type: ignore

src/prefect/core/flow.py

@@ -1270,7 +1270,10 @@ def deploy(
         Returns:
             - str: the ID of the flow that was deployed
         """
-        warnings.warn("flow.deploy() will be deprecated in an upcoming release. Please use flow.register()", UserWarning)
+        warnings.warn(
+            "flow.deploy() will be deprecated in an upcoming release. Please use flow.register()",
+            UserWarning,
+        )
 
         return self.register(
             project_name=project_name,

src/prefect/utilities/logging.py

@@ -10,6 +10,7 @@
 """
 import atexit
 import logging
+import sys
 import threading
 import time
 from queue import Queue, Empty
@@ -23,10 +24,10 @@
 
 class CloudHandler(logging.StreamHandler):
     def __init__(self) -> None:
-        super().__init__()
+        super().__init__(sys.stdout)
         self.client = None
         self.logger = logging.getLogger("CloudHandler")
-        handler = logging.StreamHandler()
+        handler = logging.StreamHandler(sys.stdout)
         formatter = logging.Formatter(context.config.logging.format)
         formatter.converter = time.gmtime  # type: ignore
         handler.setFormatter(formatter)
@@ -137,7 +138,7 @@ def configure_logging(testing: bool = False) -> logging.Logger:
     """
     name = "prefect-test-logger" if testing else "prefect"
     logger = logging.getLogger(name)
-    handler = logging.StreamHandler()
+    handler = logging.StreamHandler(sys.stdout)
     formatter = logging.Formatter(context.config.logging.format)
     formatter.converter = time.gmtime  # type: ignore
     handler.setFormatter(formatter)