Merge pull request #113 from Helene/automatic_config_refresh

Trigger metadata refresh by zimon sensors configuration changes automtically

Author: Helene

source/bridgeLogger.py

@@ -54,8 +54,8 @@ def configureLogging(logPath, logfile, loglevel=logging.INFO):
 
     logToFile = True if logfile else False
 
-    formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)-8s - %(message)s')
-    formatter1 = logging.Formatter('%(asctime)s - %(levelname)-8s - %(message)s', datefmt='%Y-%m-%d %H:%M')
+    formatter = logging.Formatter('%(asctime)s - %(name)s - %(threadName)-20s - %(levelname)-8s - %(message)s')
+    formatter1 = logging.Formatter('%(asctime)s - %(threadName)-20s - %(levelname)-8s - %(message)s', datefmt='%Y-%m-%d %H:%M')
 
     # prepare the logger
     logging.setLoggerClass(MyLogger)
@@ -85,3 +85,7 @@ def configureLogging(logPath, logfile, loglevel=logging.INFO):
 
     logger.propagate = False  # prevent propagation to default (console) logger
     return logger
+
+
+def getBridgeLogger():
+    return logging.getLogger(__name__)

source/messages.py

@@ -55,5 +55,11 @@
        'Query2port': 'For better bridge performance multithreaded port {} will be used',
        'CollectorConnInfo': 'Connection to the collector server established successfully',
        'BridgeVersionInfo': ' *** IBM Spectrum Scale bridge for Grafana - Version: {} ***',
-       'FileNotFound': 'The file {} not found.'
+       'FileNotFound': 'The file {} not found.',
+       'FileChanged': 'The file {} has been changed.',
+       'FileAddedToWatch': 'The file {} added to watching files.',
+       'StartWatchingFiles': 'Start watching file changes in the path {}.',
+       'StopWatchingFiles': 'Stop watching file changes in the path {}.',
+       'PathNoCfgFiles': 'The path does not contain any configuration files.',
+       'UnhandledError': 'Unhandled error: {}'
        }

source/watcher.py

@@ -0,0 +1,94 @@
+'''
+##############################################################################
+# Copyright 2023 IBM Corp.
+#
+# 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.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+##############################################################################
+
+Created on Sep 22, 2023
+
+@author: HWASSMAN
+'''
+
+import os
+import time
+from bridgeLogger import getBridgeLogger
+from messages import MSG
+
+
+class ConfigWatcher(object):
+    running = False
+    refresh_delay_secs = 30
+
+    def __init__(self, watch_paths, call_func_on_change=None, *args, **kwargs):
+        self._cached_stamp = {}
+        self.logger = getBridgeLogger()
+        self.paths = watch_paths
+        self.filenames = set()
+        self.call_func_on_change = call_func_on_change
+        self.args = args
+        self.kwargs = kwargs
+
+    def update_files_list(self):
+        oldfiles = self.filenames.copy()
+        for path in self.paths:
+            if os.path.isfile(path):
+                self.filenames.add(path)
+            elif os.path.isdir(path):
+                for root, _, files in os.walk(path):
+                    for file in files:
+                        if file.endswith(".cfg"):
+                            self.filenames.add(os.path.join(root, file))
+            else:
+                self.logger.trace(MSG['PathNoCfgFiles'].format(path))
+        for file in self.filenames.difference(oldfiles):
+            self.logger.debug(MSG['FileAddedToWatch'].format(file))
+
+    def look(self):
+        """ Function to check if a file timestamp has changed"""
+        for filename in self.filenames:
+            stamp = os.stat(filename).st_mtime
+            if filename not in self._cached_stamp:
+                self._cached_stamp[filename] = stamp
+            elif stamp != self._cached_stamp[filename]:
+                self._cached_stamp[filename] = stamp
+                # File has changed, so do something...
+                self.logger.info(MSG['FileChanged'].format(filename))
+                if self.call_func_on_change is not None:
+                    self.call_func_on_change(*self.args, **self.kwargs)
+
+    def watch(self):
+        """ Function to keep watching in a loop """
+        self.running = True
+        self.logger.debug(MSG['StartWatchingFiles'].format(self.paths))
+        while self.running:
+            try:
+                # Look for changes
+                time.sleep(self.refresh_delay_secs)
+                self.update_files_list()
+                self.look()
+            except KeyboardInterrupt:
+                self.logger.details(MSG['StopWatchingFiles'].format(self.paths))
+                break
+            except FileNotFoundError as e:
+                # Action on file not found
+                self.logger.warning(MSG['FileNotFound'].format(e.filename))
+                pass
+            except Exception as e:
+                self.logger.warning(MSG['StopWatchingFiles'].format(self.paths))
+                self.logger.details(MSG['UnhandledError'].format(type(e).__name__))
+                break
+
+    def stop_watch(self):
+        """ Function to break watching """
+        self.running = False

source/zimonGrafanaIntf.py

@@ -37,9 +37,11 @@
 from metaclasses import Singleton
 from bridgeLogger import configureLogging
 from confParser import getSettings
+from watcher import ConfigWatcher
 from collections import defaultdict
 from timeit import default_timer as timer
 from time import sleep
+from threading import Thread
 
 
 class MetadataHandler(metaclass=Singleton):
@@ -108,11 +110,14 @@ def __initializeTables(self):
                 return
         raise ValueError(MSG['NoData'])
 
-    def update(self):
+    def update(self, refresh_all=False):
         '''Read the topology from ZIMon and update
         the tables for metrics, keys, key elements (tag keys)
         and key values (tag values)'''
 
+        if refresh_all:
+            self.__sensorsConf = SensorConfig.readSensorsConfigFromMMSDRFS(self.logger)
+
         tstart = timer()
         self.__metaData = Topo(self.qh.getTopology())
         tend = timer()
@@ -606,6 +611,22 @@ def resolveAPIKeyValue(storedKey):
         return storedKey
 
 
+def refresh_metadata(refresh_all=False):
+    md = MetadataHandler()
+    md.update(refresh_all)
+
+
+def watch_config():
+    files_to_watch = []
+    if os.path.isfile(SensorConfig.mmsdrfsFile):
+        files_to_watch.append(SensorConfig.mmsdrfsFile)
+    else:
+        files_to_watch.append(SensorConfig.zimonFile)
+
+    watcher = ConfigWatcher(files_to_watch, refresh_metadata, refresh_all=True)
+    watcher.watch()
+
+
 def main(argv):
     # parse input arguments
     args, msg = getSettings(argv)
@@ -695,6 +716,9 @@ def main(argv):
     try:
         cherrypy.engine.start()
         logger.info("server started")
+        t = Thread(name='ConfigWatchThread', target=watch_config)
+        t.start()
+        # t.join()
         with open("/proc/{}/stat".format(os.getpid())) as f:
             data = f.read()
         foreground_pid_of_group = data.rsplit(" ", 45)[1]

tests/test_configWatcher.py

@@ -0,0 +1,44 @@
+import os
+import time
+from source.watcher import ConfigWatcher
+from source.bridgeLogger import configureLogging
+from nose2.tools.decorators import with_setup
+from threading import Thread
+
+
+def my_setup():
+    global path, logger, mainSensorsConfig, wrongSensorsConfig, zimonFile, sensorsCount
+    path = os.getcwd()
+    logger = configureLogging(path, None)
+    mainSensorsConfig = 'ZIMonSensors.cfg'
+    wrongSensorsConfig = 'ZIMonSensors-protocols-wrong.cfg'
+    sensorsCount = 0
+
+
+@with_setup(my_setup)
+def test_case01():
+    dummyFile = os.path.join(path, wrongSensorsConfig)
+    cw = ConfigWatcher([dummyFile])
+    assert len(cw.paths) == 1
+    assert len(cw.filenames) == 0
+    t = Thread(name='ConfigWatchThread', target=cw.watch)
+    t.start()
+    time.sleep(3)
+    cw.stop_watch()
+    t.join()
+    assert len(cw.paths) == 1
+    assert len(cw.filenames) == 0
+
+
+@with_setup(my_setup)
+def test_case02():
+    cw = ConfigWatcher([path])
+    assert len(cw.paths) > 0
+    assert len(cw.filenames) == 0
+    t = Thread(name='ConfigWatchThread', target=cw.watch)
+    t.start()
+    time.sleep(3)
+    cw.stop_watch()
+    t.join()
+    assert len(cw.paths) > 0
+    assert len(cw.filenames) > 1