Created new module labrad.logging to unify and streamline logging process

labrad/logging.py

@@ -0,0 +1,143 @@
+"""
+labrad.logging
+
+Contains functions to set up logging.
+"""
+
+import os
+import sys
+import logging
+
+__all__ = ["labradLogFormatter", "_LoggerWriter", "setupLogging"]
+
+
+labradLogFormatter = logging.Formatter(
+    "%(asctime)s [%(name)-15.15s] [%(sender_host)-15.15s] [%(sender_name)-25.25s] [%(levelname)-10.10s]  %(message)s"
+)
+
+
+class _LoggerWriter:
+    """
+    Redirects stdout to logger.
+    """
+    encoding = 'utf-8'
+
+    def __init__(self, level):
+        self.level = level
+
+    def write(self, message):
+        if message != '\n':
+            self.level(message)
+
+    def flush(self):
+        self.level(sys.stderr)
+
+
+def setupLogging(
+        logger_name, sender=None, extraDict=None,
+        logHandlers=[], log_level=logging.DEBUG,
+        logfile=None,
+        syslog=True, syslog_rfc='5424',
+        syslog_socket=(os.environ['LABRADHOST'], os.environ['EGGS_LABRAD_SYSLOG_PORT'])
+    ):
+    """
+    Sets up the logger.
+    Arguments:
+        logger_name     : the name of the logger to set up.
+        sender          : the sender.
+        extraDict       : the logging dict to send with each log.
+        logHandlers     : extra handlers to send the logger.
+        log_level       : the default logging level.
+        logfile         : the directory to create a logfile in.
+        syslog          : whether to create syslog handlers.
+        syslog_rfc      : the RFC standard for syslog.
+        syslog_socket   : the syslog socket to log to if syslog is True.
+    """
+    from socket import SOCK_STREAM, gethostname
+
+    # ensure we can create a custom loghandler with labels specific to each sender
+    if (sender is None) and (extraDict is None):
+        raise Exception("Either sender or extraDict must be specified.")
+    elif extraDict is None:
+        extraDict = {
+            'sender_host': gethostname(),
+            'sender_name': sender.__class__.__name__,
+        }
+
+    # create and configure logger
+    logging.basicConfig(level=log_level, handlers=None)
+    logger = logging.getLogger(logger_name)
+    logger.propagate = False
+
+    # remove any existing loggers, keeping only those related to labrad
+    handlers = []
+    for name, logger_obj in logging.Logger.manager.loggerDict.items():
+        # check log handlers have already been specified
+        if isinstance(logger_obj, logging.Logger) and (name == logger_name):
+            for log_handler in logger_obj.handlers:
+                handlers.append(log_handler)
+        # otherwise, turn off any loggers that aren't labrad related
+        elif isinstance(logger_obj, logging.Logger) and ('labrad' not in name):
+            logger_obj.disabled = True
+
+    # add extra log handlers
+    for log_handler in logHandlers:
+        try:
+            logger.addHandler(log_handler)
+        except Exception as e:
+            print(e)
+            print("Error: unable to add log_handler {}.".format(log_handler))
+
+    # only add core handlers if they don't already exist
+    # this prevents the duplication of log messages
+    if len(handlers) == 0:
+
+        # create console handler
+        console_handler = logging.StreamHandler(sys.stdout)
+        console_handler.setFormatter(labradLogFormatter)
+        logger.addHandler(console_handler)
+
+        # create logfile
+        if logfile is not None:
+            from logging.handlers import FileHandler
+            logfile_handler = FileHandler(logfile)
+            logfile_handler.setFormatter(labradLogFormatter)
+            logger.addHandler(logfile_handler)
+
+        if syslog:
+            # create syslog handler for RFC3164
+            if syslog_rfc == '3164':
+                # todo: add extradict to this syslog handler
+                from logging.handlers import SysLogHandler
+                syslog_handler = SysLogHandler(address=syslog_socket)
+                syslog_handler.setFormatter(labradLogFormatter)
+                logger.addHandler(syslog_handler)
+
+            # create syslog handler for RFC5424
+            elif syslog_rfc == '5424':
+                try:
+                    from rfc5424logging import Rfc5424SysLogHandler
+                    syslog5424_handler = Rfc5424SysLogHandler(
+                        address=syslog_socket,
+                        socktype=SOCK_STREAM,
+                        enterprise_id=88888
+                    )
+                    logger.addHandler(syslog5424_handler)
+                except ImportError:
+                    print("Error: RFC5424 syslog handler module is not installed.")
+                except Exception as e:
+                    print(e)
+                    print("Error: unable to create RFC5424 syslog handler.")
+
+    # adapt logger and return
+    if syslog and (syslog_rfc == '5424'):
+        try:
+            from rfc5424logging.adapter import Rfc5424SysLogAdapter
+            logger_adapter = Rfc5424SysLogAdapter(logger, extraDict)
+            return logger_adapter
+        except ImportError:
+            print("Error: RFC5424 syslog handler module is not installed.")
+        except Exception as e:
+            print("Error: unable to create RFC5424 syslog handler.")
+    else:
+        return logger