Running into xml invalid attribute name for NETCONF python library

Question

I'm using a high level python library ncclient to edit the configuration of a NETCONF device but I run into this error:

ValueError: Invalid attribute name u'xmlns:if'

I suspect it has something to do with an xml namespace problem since the lxml library is complaining about an attribute name

All I'm doing is creating a connection to the device and then closing it

manager = ncclient.manager.connect(
    host=host,
    port=port,
    username=username,
    password=b64decode(password),
    device_params={
        "name": "nexus",
        "ssh_subsystem_name": "xmlagent"
    }
)
manager.close_session()

Here's a stack trace:

Traceback (most recent call last):
  File "./switch_config.py", line 41, in <module>
    main()
  File "./switch_config.py", line 26, in main
    manager.close_session()
  File "/usr/lib/python2.6/site-packages/ncclient/manager.py", line 107, in wrapper
    return self.execute(op_cls, *args, **kwds)
  File "/usr/lib/python2.6/site-packages/ncclient/manager.py", line 174, in execute
    raise_mode=self._raise_mode).request(*args, **kwds)
  File "/usr/lib/python2.6/site-packages/ncclient/operations/session.py", line 28, in request
    return self._request(new_ele("close-session"))
  File "/usr/lib/python2.6/site-packages/ncclient/operations/rpc.py", line 290, in _request
    req = self._wrap(op)
  File "/usr/lib/python2.6/site-packages/ncclient/operations/rpc.py", line 275, in _wrap
    **self._device_handler.get_xml_extra_prefix_kwargs())
  File "/usr/lib/python2.6/site-packages/ncclient/xml_.py", line 153, in <lambda>
    new_ele = lambda tag, attrs={}, **extra: etree.Element(qualify(tag), attrs, **extra)
  File "lxml.etree.pyx", line 2812, in lxml.etree.Element (src/lxml/lxml.etree.c:61433)
  File "apihelpers.pxi", line 123, in lxml.etree._makeElement (src/lxml/lxml.etree.c:13864)
  File "apihelpers.pxi", line 111, in lxml.etree._makeElement (src/lxml/lxml.etree.c:13736)
  File "apihelpers.pxi", line 263, in lxml.etree._initNodeAttributes (src/lxml/lxml.etree.c:15391)
  File "apihelpers.pxi", line 1524, in lxml.etree._attributeValidOrRaise (src/lxml/lxml.etree.c:26886)
ValueError: Invalid attribute name u'xmlns:if'

Answer 1

I eventually got it work on NX-OS by:

Remove all the namespaces in ncclient/devices/nexus.py and add namespace "xmlns":"http://www.cisco.com/nxos:1.0:netconf".

def get_xml_base_namespace_dict(self):
    return { "xmlns":"http://www.cisco.com/nxos:1.0:netconf" }      #Add root namespace

def get_xml_extra_prefix_kwargs(self):
    d = {
            # "xmlns:nxos":"http://www.cisco.com/nxos:1.0",           #remove other namespaces
            # "xmlns:if":"http://www.cisco.com/nxos:1.0:if_manager"
        }
    d.update(self.get_xml_base_namespace_dict())
    return d