Refined log redirection code

SDP/SDP/SDP.py

@@ -30,7 +30,7 @@ from lofar_logging import device_logging_to_python, log_exceptions
 
 __all__ = ["SDP", "main"]
 
-@device_logging_to_python("SDP")
+@device_logging_to_python({"device": "SDP"})
 class SDP(Device):
     """
 

SDP/SDP/lofar_logging.py

 import logging
-import tango
 from functools import wraps
 
-def configured_logger(name=''):
-    logger = logging.getLogger(name)
+def configure_logger(logger: logging.Logger, log_extra=None):
     logger.setLevel(logging.DEBUG)
 
     try:
-        from logstash_async.handler import AsynchronousLogstashHandler
+        from logstash_async.handler import AsynchronousLogstashHandler, LogstashFormatter
 
-        logger.addHandler(AsynchronousLogstashHandler("elk", 5959, database_path='logstash_test.db'))
+        # log to the tcp_input of logstash in our ELK stack
+        handler = AsynchronousLogstashHandler("elk", 5959, database_path='pending_log_messages.db')
+
+        # configure log messages 
+        formatter = LogstashFormatter(extra=log_extra, tags=["python", "lofar"])
+        handler.setFormatter(formatter)
+
+        # install the handler
+        logger.addHandler(handler)
     except Exception:
         logger.exception("Cannot import or configure logstash_async module, not forwarding logs to ELK stack.")
 
     return logger
 
-def device_logging_to_python(name = ''):
+def device_logging_to_python(log_extra: dict = None):
     """ Call this on a Tango Device instance or class to have your Tango Device log to python instead. """
 
-    logger = configured_logger(name)
-
     def inner(cls):
+        # Create a logger that logs to ELK, dedicated for this class
+        logger = logging.getLogger(cls.__name__)
+        configure_logger(logger, log_extra)
+
         # Monkey patch the python logger to replace the tango logger
         cls.debug_stream = logger.debug
         cls.info_stream = logger.info
@@ -34,6 +42,8 @@ def device_logging_to_python(name = ''):
     return inner
 
 def log_exceptions(func):
+    """ Decorator that logs all exceptions that the function raises. """
+
     @wraps(func)
     def inner(self, *args, **kwargs):
         try: