Don't monkey patch logging on import

Previously swift.common.utils monkey patched logging.thread,
logging.threading, and logging._lock upon import with eventlet
threading modules, but that is no longer reasonable or necessary.

With py3, the existing logging._lock is not patched by eventlet,
unless the logging module is reloaded. The existing lock is not
tracked by the gc so would not be found by eventlet's
green_existing_locks().

Instead we group all monkey patching into utils function and apply
patching consistently across daemons and WSGI servers.

Co-Authored-By: Clay Gerrard <clay.gerrard@gmail.com>
Co-Authored-By: Alistair Coles <alistairncoles@gmail.com>
Closes-Bug: #1380815
Change-Id: I6f35ad41414898fb7dc5da422f524eb52ff2940f

3 files changed, 25 insertions, 13 deletions

diff --git a/swift/common/daemon.py b/swift/common/daemon.py
index 773ca9424..300710e98 100644
--- a/swift/common/daemon.py
+++ b/swift/common/daemon.py
@@ -20,8 +20,8 @@ import time
 import signal
 from re import sub
 
+import eventlet
 import eventlet.debug
-from eventlet.hubs import use_hub
 
 from swift.common import utils
 
@@ -281,7 +281,9 @@ def run_daemon(klass, conf_file, section_name='', once=False, **kwargs):
         # and results in an exit code of 1.
         sys.exit(e)
 
-    use_hub(utils.get_hub())
+    # patch eventlet/logging early
+    utils.monkey_patch()
+    eventlet.hubs.use_hub(utils.get_hub())
 
     # once on command line (i.e. daemonize=false) will over-ride config
     once = once or not utils.config_true_value(conf.get('daemonize', 'true'))
diff --git a/swift/common/utils/__init__.py b/swift/common/utils/__init__.py
index 16dc58807..cdaa0b807 100644
--- a/swift/common/utils/__init__.py
+++ b/swift/common/utils/__init__.py
@@ -119,16 +119,10 @@ from swift.common.utils.timestamp import (  # noqa
     normalize_delete_at_timestamp,
 )
 
-# logging doesn't import patched as cleanly as one would like
 from logging.handlers import SysLogHandler
 import logging
-logging.thread = eventlet.green.thread
-logging.threading = eventlet.green.threading
-logging._lock = logging.threading.RLock()
-# setup notice level logging
+
 NOTICE = 25
-logging.addLevelName(NOTICE, 'NOTICE')
-SysLogHandler.priority_map['NOTICE'] = 'notice'
 
 # Used by hash_path to offer a bit more security when generating hashes for
 # paths. It simply appends this value to all paths; guessing the hash a path
@@ -442,6 +436,17 @@ def config_read_prefixed_options(conf, prefix_name, defaults):
     return params
 
 
+def logging_monkey_patch():
+    # explicitly patch the logging lock
+    logging._lock = logging.threading.RLock()
+    # setup notice level logging
+    logging.addLevelName(NOTICE, 'NOTICE')
+    SysLogHandler.priority_map['NOTICE'] = 'notice'
+    # Trying to log threads while monkey-patched can lead to deadlocks; see
+    # https://bugs.launchpad.net/swift/+bug/1895739
+    logging.logThreads = 0
+
+
 def eventlet_monkey_patch():
     """
     Install the appropriate Eventlet monkey patches.
@@ -452,9 +457,14 @@ def eventlet_monkey_patch():
     #         if thread is monkey-patched.
     eventlet.patcher.monkey_patch(all=False, socket=True, select=True,
                                   thread=True)
-    # Trying to log threads while monkey-patched can lead to deadlocks; see
-    # https://bugs.launchpad.net/swift/+bug/1895739
-    logging.logThreads = 0
+
+
+def monkey_patch():
+    """
+    Apply all swift monkey patching consistently in one place.
+    """
+    eventlet_monkey_patch()
+    logging_monkey_patch()
 
 
 def validate_configuration():
diff --git a/swift/common/wsgi.py b/swift/common/wsgi.py
index 7c39a89e2..99dc4c203 100644
--- a/swift/common/wsgi.py
+++ b/swift/common/wsgi.py
@@ -838,7 +838,7 @@ def run_wsgi(conf_path, app_section, *args, **kwargs):
             return 1
 
     # patch event before loadapp
-    utils.eventlet_monkey_patch()
+    utils.monkey_patch()
 
     # Ensure the configuration and application can be loaded before proceeding.
     global_conf = {'log_name': log_name}