Better defaults that fix volume support

The default value for block_device_mapping should not be a path, rather should be the name of the actual device in /dev.  The device_path should also be defaulted to the fully qualified path to that device.  This patch fixes volume support and does not require you to set reddwarf_volume_support=False to get a guest to boot sucessfully.

fixes bug: 1084802

Change-Id: I8aa8582da7b400c91f761a2974f859df8cd45003

etc/reddwarf/reddwarf-taskmanager.conf.sample

@@ -33,8 +33,8 @@ nova_volume_url = http://localhost:8776/v1
 
 # Config options for enabling volume service
 reddwarf_volume_support = True
-block_device_mapping = /var/lib/mysql
-device_path = /var/lib/mysql
+block_device_mapping = vdb
+device_path = /dev/vdb
 mount_point = /var/lib/mysql
 volume_time_out=30
 server_delete_time_out=480

etc/reddwarf/reddwarf.conf.sample

@@ -46,8 +46,8 @@ add_addresses = True
 
 # Config options for enabling volume service
 reddwarf_volume_support = True
-block_device_mapping = /var/lib/mysql
-device_path = /var/lib/mysql
+block_device_mapping = vdb
+device_path = /dev/vdb
 mount_point = /var/lib/mysql
 max_accepted_volume_size = 10
 max_instances_per_user = 5

reddwarf/tests/fakes/nova.py

@@ -362,7 +362,7 @@ class FakeVolume(object):
         self._current_status = "BUILD"
         # For some reason we grab this thing from device then call it mount
         # point.
-        self.device = "/var/lib/mysql"
+        self.device = "vdb"
 
     def __repr__(self):
         msg = ("FakeVolume(id=%s, size=%s, display_name=%s, "