From 36d1dc45eb6add18273b03af4c02dc89966859b0 Mon Sep 17 00:00:00 2001
From: Rafael Zalamena <rzalamena@gmail.com>
Date: Thu, 29 Jun 2017 17:55:33 -0300
Subject: [PATCH] topolog: implement a logging abstraction

The default logger (root) is already being used by Mininet, so to allow
customizing logging output and configuring log files Topolog was
created. Topolog is no more than a thin layer abstraction to call
logging functions without using the 'root' logger.
---
 tests/topotests/lib/topogen.py |  4 ++
 tests/topotests/lib/topolog.py | 70 ++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)
 create mode 100644 tests/topotests/lib/topolog.py

diff --git a/tests/topotests/lib/topogen.py b/tests/topotests/lib/topogen.py
index 2b2ea5dcb5..d4e08a3461 100644
--- a/tests/topotests/lib/topogen.py
+++ b/tests/topotests/lib/topogen.py
@@ -48,6 +48,7 @@ from mininet.log import setLogLevel
 from mininet.cli import CLI
 
 from lib import topotest
+from lib.topolog import logger, logger_config
 
 CWD = os.path.dirname(os.path.realpath(__file__))
 
@@ -214,6 +215,9 @@ class Topogen(object):
         if log_level is None:
             log_level = self.config.get('topogen', 'verbosity')
 
+        # Set python logger level
+        logger_config.set_log_level(log_level)
+
         # Run mininet
         setLogLevel(log_level)
         self.net.start()
diff --git a/tests/topotests/lib/topolog.py b/tests/topotests/lib/topolog.py
new file mode 100644
index 0000000000..0a192ce285
--- /dev/null
+++ b/tests/topotests/lib/topolog.py
@@ -0,0 +1,70 @@
+#
+# topolog.py
+# Library of helper functions for NetDEF Topology Tests
+#
+# Copyright (c) 2017 by
+# Network Device Education Foundation, Inc. ("NetDEF")
+#
+# Permission to use, copy, modify, and/or distribute this software
+# for any purpose with or without fee is hereby granted, provided
+# that the above copyright notice and this permission notice appear
+# in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NETDEF DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NETDEF BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
+# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+# OF THIS SOFTWARE.
+#
+
+"""
+Logging utilities for topology tests.
+
+This file defines our logging abstraction.
+"""
+
+import logging
+
+# Helper dictionary to convert Topogen logging levels to Python's logging.
+DEBUG_TOPO2LOGGING = {
+    'debug': logging.DEBUG,
+    'info': logging.INFO,
+    'output': logging.INFO,
+    'warning': logging.WARNING,
+    'error': logging.ERROR,
+    'critical': logging.CRITICAL,
+}
+
+#
+# Logger class definition
+#
+
+class Logger(object):
+    """
+    Logger class that encapsulates logging functions, internaly it uses Python
+    logging module with a separated instance instead of global.
+
+    Default logging level is 'info'.
+    """
+
+    def __init__(self):
+        self.logger = logging.Logger('topolog', level=logging.INFO)
+        self.handler = logging.StreamHandler()
+        self.handler.setFormatter(
+            logging.Formatter(fmt='%(asctime)s %(levelname)s: %(message)s')
+        )
+        self.logger.addHandler(self.handler)
+
+    def set_log_level(self, level):
+        "Set the logging level"
+        self.logger.setLevel(DEBUG_TOPO2LOGGING.get(level))
+
+#
+# Global variables
+#
+
+logger_config = Logger()
+logger = logger_config.logger
-- 
2.39.5