This commit consists of:
1) Dockerizing the netconf server
2) Update proto2yang to support module imports
3) Provide a set of yang modules derived from the proto files in voltha.
   These files as well as the slight mmodifications to the proto files are
   provided in the experiments/netconf/proto2yang directory
4) Code to automatically pull proto files from voltha into the netconf server,
   compiles them and produce the yang equivalent files.
5) Add a getvoltha netconf API to provide voltha state information (basic at
   this time).  There is potential to make this generic once we experiment
   with additional APIs

Change-Id: I94f3a1f871b8025ad675d5f9b9b626d1be8b8d36
diff --git a/netconf/nc_rpc/ext/get_voltha.py b/netconf/nc_rpc/ext/get_voltha.py
new file mode 100644
index 0000000..a619875
--- /dev/null
+++ b/netconf/nc_rpc/ext/get_voltha.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python
+#
+# Copyright 2016 the original author or authors.
+#
+# 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.
+#
+from lxml import etree
+import structlog
+from netconf.nc_rpc.rpc import Rpc
+import netconf.nc_common.error as ncerror
+from netconf.constants import Constants as C
+from netconf.utils import filter_tag_match
+from twisted.internet.defer import inlineCallbacks, returnValue
+import dicttoxml
+from simplejson import dumps, load
+
+log = structlog.get_logger()
+
+
+class GetVoltha(Rpc):
+    def __init__(self, rpc_request, rpc_method, grpc_client, session):
+        super(GetVoltha, self).__init__(rpc_request, rpc_method,
+                                        grpc_client, session)
+        self._validate_parameters()
+
+    @inlineCallbacks
+    def execute(self):
+        log.info('get-voltha-request', session=self.session.session_id)
+        if self.rpc_response.is_error:
+            returnValue(self.rpc_response)
+
+        # Invoke voltha via the grpc client
+        res_dict = yield self.grpc_client.get_voltha_instance()
+
+        # convert dict to xml
+        xml = dicttoxml.dicttoxml(res_dict)
+        log.info('voltha-info', res=res_dict, xml=xml)
+
+        self.rpc_response.node = self.get_root_element(xml)
+        self.rpc_response.is_error = False
+
+        returnValue(self.rpc_response)
+
+
+    def _validate_parameters(self):
+        log.info('validate-parameters', session=self.session.session_id)
+        self.params = self.rpc_method.getchildren()
+        if len(self.params) > 1:
+            self.rpc_response.is_error = True
+            self.rpc_response.node = ncerror.BadMsg(self.rpc_request)
+            return
+
+        if self.params and not filter_tag_match(self.params[0], C.NC_FILTER):
+            self.rpc_response.is_error = True
+            self.rpc_response.node = ncerror.UnknownElement(
+                self.rpc_request, self.params[0])
+            return
+
+        if not self.params:
+            self.params = [None]