Submit python logging library seed code

[logging-analytics.git] / pylog / onaplogging / logWatchDog.py

diff --git a/pylog/onaplogging/logWatchDog.py b/pylog/onaplogging/logWatchDog.py
new file mode 100644 (file)
index 0000000..e0673e3
--- /dev/null
+++ b/pylog/onaplogging/logWatchDog.py
@@ -0,0 +1,95 @@
+# Copyright (c) 2018 VMware, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+
+import os
+import yaml
+import traceback
+from logging import config
+from watchdog.observers import Observer
+from watchdog.events import FileSystemEventHandler
+
+
+__all__ = ['patch_loggingYaml']
+
+
+def _yaml2Dict(filename):
+
+    with open(filename, 'rt') as f:
+        return yaml.load(f.read())
+
+
+class FileEventHandlers(FileSystemEventHandler):
+
+    def __init__(self, filepath):
+
+        FileSystemEventHandler.__init__(self)
+        self.filepath = filepath
+        self.currentConfig = None
+
+    def on_modified(self, event):
+        try:
+            if event.src_path == self.filepath:
+                newConfig = _yaml2Dict(self.filepath)
+                print ("reload logging configure file %s" % event.src_path)
+                config.dictConfig(newConfig)
+                self.currentConfig = newConfig
+
+        except Exception as e:
+            traceback.print_exc(e)
+            print ("Reuse the old configuration to avoid this "
+                   "exception terminate program")
+            if self.currentConfig:
+                config.dictConfig(self.currentConfig)
+
+
+def _yamlConfig(filepath=None, watchDog=None):
+
+    """
+    load logging configureation from yaml file and monitor file status
+
+    :param filepath: logging yaml configure file absolute path
+    :param watchDog: monitor yaml file identifier status
+    :return:
+    """
+    if os.path.isfile(filepath) is False:
+        raise OSError("wrong file")
+
+    dirpath = os.path.dirname(filepath)
+    event_handler = None
+
+    try:
+        dictConfig = _yaml2Dict(filepath)
+        #  The watchdog could monitor yaml file status,if be modified
+        #  will send a notify  then we could reload logging configuration
+        if watchDog:
+            observer = Observer()
+            event_handler = FileEventHandlers(filepath)
+            observer.schedule(event_handler=event_handler, path=dirpath,
+                              recursive=False)
+            observer.setDaemon(True)
+            observer.start()
+
+        config.dictConfig(dictConfig)
+
+        if event_handler:
+            # here we keep the correct configuration for reusing
+            event_handler.currentConfig = dictConfig
+
+    except Exception as e:
+        traceback.print_exc(e)
+
+
+def patch_loggingYaml():
+
+    # The patch to add yam config forlogginf and runtime
+    # reload logging when modify yaml file
+    config.yamlConfig = _yamlConfig