Add support for netconf network discovery (#25435)

* Add support for netconf network discovery

* Fix unit test failure

lib/ansible/plugins/connection/netconf.py

@@ -66,16 +66,24 @@ class Connection(Rpc, ConnectionBase):
 
         display.display('ssh connection done, stating ncclient', log_only=True)
 
-        allow_agent = True
+        self.allow_agent = True
         if self._play_context.password is not None:
-            allow_agent = False
+            self.allow_agent = False
 
-        key_filename = None
+        self.key_filename = None
         if self._play_context.private_key_file:
-            key_filename = os.path.expanduser(self._play_context.private_key_file)
+            self.key_filename = os.path.expanduser(self._play_context.private_key_file)
 
-        if not self._network_os:
-            raise AnsibleConnectionFailure('network_os must be set for netconf connections')
+        network_os = self._play_context.network_os
+
+        if not network_os:
+            for cls in netconf_loader.all(class_only=True):
+                network_os = cls.guess_network_os(self)
+                if network_os:
+                    display.display('discovered network_os %s' % network_os, log_only=True)
+
+        if not network_os:
+            raise AnsibleConnectionFailure('Unable to automatically determine host network os. Please ansible_network_os value')
 
         try:
             self._manager = manager.connect(
@@ -83,12 +91,12 @@ class Connection(Rpc, ConnectionBase):
                 port=self._play_context.port or 830,
                 username=self._play_context.remote_user,
                 password=self._play_context.password,
-                key_filename=str(key_filename),
+                key_filename=str(self.key_filename),
                 hostkey_verify=C.HOST_KEY_CHECKING,
                 look_for_keys=C.PARAMIKO_LOOK_FOR_KEYS,
-                allow_agent=allow_agent,
+                allow_agent=self.allow_agent,
                 timeout=self._play_context.timeout,
-                device_params={'name': self._network_os}
+                device_params={'name': network_os}
             )
         except SSHUnknownHostError as exc:
             raise AnsibleConnectionFailure(str(exc))
@@ -100,12 +108,12 @@ class Connection(Rpc, ConnectionBase):
 
         self._connected = True
 
-        self._netconf = netconf_loader.get(self._network_os, self)
+        self._netconf = netconf_loader.get(network_os, self)
         if self._netconf:
             self._rpc.add(self._netconf)
-            display.display('loaded netconf plugin for network_os %s' % self._network_os, log_only=True)
+            display.display('loaded netconf plugin for network_os %s' % network_os, log_only=True)
         else:
-            display.display('unable to load netconf for network_os %s' % self._network_os)
+            display.display('unable to load netconf for network_os %s' % network_os)
 
         return 0, to_bytes(self._manager.session_id, errors='surrogate_or_strict'), b''
 

lib/ansible/plugins/netconf/__init__.py

@@ -176,6 +176,13 @@ class NetconfBase(with_metaclass(ABCMeta, object)):
         """
         pass
 
+    @staticmethod
+    def guess_network_os(obj):
+        """Identifies the operating system of
+            network device.
+        """
+        pass
+
     def get_base_rpc(self):
         """Returns list of base rpc method supported by remote device"""
         return ['get_config', 'edit_config', 'get_capabilities', 'get']

lib/ansible/plugins/netconf/junos.py

@@ -20,14 +20,23 @@ from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
 
 import json
+import re
 
 from xml.etree.ElementTree import fromstring
 
-from ansible.module_utils._text import to_bytes, to_text
+from ansible import constants as C
+from ansible.module_utils._text import to_text
+from ansible.errors import AnsibleConnectionFailure, AnsibleError
 from ansible.plugins.netconf import NetconfBase
 from ansible.plugins.netconf import ensure_connected
 
-from ncclient.xml_ import new_ele
+try:
+    from ncclient import manager
+    from ncclient.operations import RPCError
+    from ncclient.transport.errors import SSHUnknownHostError
+    from ncclient.xml_ import to_ele, to_xml, new_ele
+except ImportError:
+    raise AnsibleError("ncclient is not installed")
 
 
 class Netconf(NetconfBase):
@@ -77,3 +86,29 @@ class Netconf(NetconfBase):
         result['client_capabilities'] = [c for c in self.m.client_capabilities]
         result['session_id'] = self.m.session_id
         return json.dumps(result)
+
+    @staticmethod
+    def guess_network_os(obj):
+
+        try:
+            m = manager.connect(
+                host=obj._play_context.remote_addr,
+                port=obj._play_context.port or 830,
+                username=obj._play_context.remote_user,
+                password=obj._play_context.password,
+                key_filename=str(obj.key_filename),
+                hostkey_verify=C.HOST_KEY_CHECKING,
+                look_for_keys=C.PARAMIKO_LOOK_FOR_KEYS,
+                allow_agent=obj.allow_agent,
+                timeout=obj._play_context.timeout
+            )
+        except SSHUnknownHostError as exc:
+            raise AnsibleConnectionFailure(str(exc))
+
+        guessed_os = None
+        for c in m.server_capabilities:
+            if re.search('junos', c):
+                guessed_os = 'junos'
+
+        m.close_session()
+        return guessed_os

test/units/plugins/connection/test_netconf.py

@@ -72,6 +72,7 @@ class TestNetconfConnectionClass(unittest.TestCase):
         mock_manager = MagicMock(name='self._manager.connect')
         type(mock_manager).session_id = PropertyMock(return_value='123456789')
         netconf.manager.connect.return_value = mock_manager
+        conn._play_context.network_os = 'default'
 
         rc, out, err = conn._connect()