BIND 10 #1984: b10-ddns should be able to specify the UNIX file path in config

[BIND 10 Development]

#1984: b10-ddns should be able to specify the UNIX file path in config
-------------------------------------+-------------------------------------
            Reporter:  jinmei        |                        Owner:
                Type:  defect        |                       Status:  new
            Priority:  medium        |                    Milestone:  Next-
           Component:  DDNS          |  Sprint-Proposed
           Sensitive:  0             |                     Keywords:
         Sub-Project:  DNS           |              Defect Severity:  N/A
Estimated Difficulty:  0             |  Feature Depending on Ticket:
         Total Hours:  0             |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
-------------------------------------+-------------------------------------
 Instead of doing this:

 {{{#!python
 SOCKET_FILE = bind10_config.DATA_PATH + '/ddns_socket'
 if "B10_FROM_BUILD" in os.environ:
     if "B10_FROM_SOURCE_LOCALSTATEDIR" in os.environ:
         SOCKET_FILE = os.environ["B10_FROM_SOURCE_LOCALSTATEDIR"] + \
             "/ddns_socket"
     else:
         SOCKET_FILE = os.environ["B10_FROM_BUILD"] + "/ddns_socket"
 }}}

 b10-ddns should be able to allow it to be configured in its config,
 and test environments use the configuration if they need to customize
 the path.

 See also http://bind10.isc.org/ticket/1539#comment:8 We should then
 allow b10-auth to get it, rather than forcing it to hardcode the
 same information.

-- 
Ticket URL: <http://bind10.isc.org/ticket/1984>
BIND 10 Development <http://bind10.isc.org>
BIND 10 Development