Adds serial port logging support

Adds serial port logging to improve troubleshooting.
Serial port settings are confugurable with the option:
"logging_serial_port_settings"

cloudbaseinit/shell.py

@@ -18,10 +18,9 @@ import sys
 
 from cloudbaseinit import init
 from cloudbaseinit.openstack.common import cfg
-from cloudbaseinit.openstack.common import log as logging
+from cloudbaseinit.utils import log as logging
 
 CONF = cfg.CONF
-LOG = logging.getLogger(__name__)
 
 
 def main():

cloudbaseinit/utils/log.py

@@ -0,0 +1,58 @@
+# Copyright 2014 Cloudbase Solutions Srl
+#
+#    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.
+
+import logging
+import serial
+
+from cloudbaseinit.openstack.common import cfg
+from cloudbaseinit.openstack.common import log as openstack_logging
+
+opts = [
+    cfg.StrOpt('logging_serial_port_settings', default=None,
+               help='Serial port logging settings. Format: '
+               '"port,baudrate,parity,bytesize", e.g.: "COM1,115200,N,8". '
+               'Set to None (default) to disable.'),
+]
+
+CONF = cfg.CONF
+CONF.register_opts(opts)
+
+
+class SerialPortHandler(logging.StreamHandler):
+    def __init__(self):
+        if CONF.logging_serial_port_settings:
+            settings = CONF.logging_serial_port_settings.split(',')
+
+            self._port = serial.Serial(port=settings[0],
+                                       baudrate=int(settings[1]),
+                                       parity=settings[2],
+                                       bytesize=int(settings[3]))
+            if not self._port.isOpen():
+                self._port.open()
+
+            super(SerialPortHandler, self).__init__(self._port)
+
+    def close(self):
+        if self._port and self._port.isOpen():
+            self._port.close()
+
+
+def setup(product_name):
+    openstack_logging.setup(product_name)
+
+    if CONF.logging_serial_port_settings:
+        log_root = openstack_logging.getLogger(product_name).logger
+
+        serialportlog = SerialPortHandler()
+        log_root.addHandler(serialportlog)