Initial set of Fabric switch test cases

Change-Id: I86fd2b67d3b773aa496f5ef61f1e1fdf51fd9925
diff --git a/Fabric/Utilities/src/python/oftest/__init__.py b/Fabric/Utilities/src/python/oftest/__init__.py
new file mode 100644
index 0000000..2be5038
--- /dev/null
+++ b/Fabric/Utilities/src/python/oftest/__init__.py
@@ -0,0 +1,56 @@
+
+# Copyright 2017-present Open Networking Foundation
+#
+# 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.
+
+
+'''Docstring to silence pylint; ignores --ignore option for __init__.py'''
+import sys
+import os
+import logging
+
+# Global config dictionary
+# Populated by oft.
+config = {}
+
+# Global DataPlane instance used by all tests.
+# Populated by oft.
+dataplane_instance = None
+
+def open_logfile(name):
+    """
+    (Re)open logfile
+
+    When using a log directory a new logfile is created for each test. The same
+    code is used to implement a single logfile in the absence of --log-dir.
+    """
+
+    _format = "%(asctime)s.%(msecs)03d  %(name)-10s: %(levelname)-8s: %(message)s"
+    _datefmt = "%H:%M:%S"
+
+    if config["log_dir"] != None:
+        filename = os.path.join(config["log_dir"], name) + ".log"
+    else:
+        filename = config["log_file"]
+
+    logger = logging.getLogger()
+
+    # Remove any existing handlers
+    for handler in logger.handlers:
+        logger.removeHandler(handler)
+        handler.close()
+
+    # Add a new handler
+    handler = logging.FileHandler(filename, mode='a')
+    handler.setFormatter(logging.Formatter(_format, _datefmt))
+    logger.addHandler(handler)