1 files changed, 99 insertions, 0 deletions
diff --git a/app/utils/logging/logger.py b/app/utils/logging/logger.py
new file mode 100644
index 0000000..bcf8287
--- /dev/null
+++ b/app/utils/logging/logger.py
@@ -0,0 +1,99 @@
+###############################################################################
+# Copyright (c) 2017 Koren Lev (Cisco Systems), Yaron Yogev (Cisco Systems)   #
+# and others                                                                  #
+#                                                                             #
+# All rights reserved. This program and the accompanying materials            #
+# are made available under the terms of the Apache License, Version 2.0       #
+# which accompanies this distribution, and is available at                    #
+# http://www.apache.org/licenses/LICENSE-2.0                                  #
+###############################################################################
+import logging
+from abc import ABC
+
+
+class Logger(ABC):
+    DEBUG = 'DEBUG'
+    INFO = 'INFO'
+    WARNING = 'WARNING'
+    ERROR = 'ERROR'
+    CRITICAL = 'CRITICAL'
+
+    PROJECT_NAME = 'CALIPSO'
+
+    levels = [DEBUG, INFO, WARNING, ERROR, CRITICAL]
+    log_format = '%(asctime)s %(levelname)s: %(message)s'
+    formatter = logging.Formatter(log_format)
+    default_level = INFO
+
+    def __init__(self, logger_name: str = PROJECT_NAME,
+                 level: str = default_level):
+        super().__init__()
+        self.check_level(level)
+        self.log = logging.getLogger(logger_name)
+        logging.basicConfig(format=self.log_format,
+                            level=level)
+        self.log.propagate = False
+        self.set_loglevel(level)
+        self.env = None
+        self.level = level
+
+    def set_env(self, env):
+        self.env = env
+
+    @staticmethod
+    def check_level(level):
+        if level.upper() not in Logger.levels:
+            raise ValueError('Invalid log level: {}. Supported levels: ({})'
+                             .format(level, ", ".join(Logger.levels)))
+
+    @staticmethod
+    def get_numeric_level(loglevel):
+        Logger.check_level(loglevel)
+        numeric_level = getattr(logging, loglevel.upper(), Logger.default_level)
+        if not isinstance(numeric_level, int):
+            raise ValueError('Invalid log level: {}'.format(loglevel))
+        return numeric_level
+
+    def set_loglevel(self, loglevel):
+        # assuming loglevel is bound to the string value obtained from the
+        # command line argument. Convert to upper case to allow the user to
+        # specify --log=DEBUG or --log=debug
+        numeric_level = self.get_numeric_level(loglevel)
+
+        for handler in self.log.handlers:
+            handler.setLevel(numeric_level)
+        self.log.setLevel(numeric_level)
+        self.level = loglevel
+
+    def _log(self, level, message, *args, exc_info=False, **kwargs):
+        self.log.log(level, message, *args, exc_info=exc_info, **kwargs)
+
+    def debug(self, message, *args, **kwargs):
+        self._log(logging.DEBUG, message, *args, **kwargs)
+
+    def info(self, message, *args, **kwargs):
+        self._log(logging.INFO, message, *args, **kwargs)
+
+    def warning(self, message, *args, **kwargs):
+        self._log(logging.WARNING, message, *args, **kwargs)
+
+    def warn(self, message, *args, **kwargs):
+        self.warning(message, *args, **kwargs)
+
+    def error(self, message, *args, **kwargs):
+        self._log(logging.ERROR, message, *args, **kwargs)
+
+    def exception(self, message, *args, **kwargs):
+        self._log(logging.ERROR, message, exc_info=True, *args, **kwargs)
+
+    def critical(self, message, *args, **kwargs):
+        self._log(logging.CRITICAL, message, *args, **kwargs)
+
+    def add_handler(self, handler):
+        handler_defined = handler.__class__ in map(lambda h: h.__class__,
+                                                   self.log.handlers)
+
+        if not handler_defined:
+            handler.setLevel(self.level)
+            handler.setFormatter(self.formatter)
+            self.log.addHandler(handler)