Refactor common network shared and platform utils code into package (#33452)

* Refactor common network shared and platform specific code into package (part-1)

As per proposal #76 refactor common network shared and platform specific
code into sub-package.
https://github.com/ansible/proposals/issues/76

*  ansible.module_utils.network.common - command shared functions
*  ansible.module_utils.network.{{ platform }} - where platform is platform specific shared functions

*  Fix review comments

* Fix review comments

lib/ansible/module_utils/network/common/netconf.py

@@ -0,0 +1,87 @@
+# This code is part of Ansible, but is an independent component.
+# This particular file snippet, and this file snippet only, is BSD licensed.
+# Modules you write using this snippet, which is embedded dynamically by Ansible
+# still belong to the author of the module, and may assign their own license
+# to the complete work.
+#
+# (c) 2017 Red Hat Inc.
+#
+# Redistribution and use in source and binary forms, with or without modification,
+# are permitted provided that the following conditions are met:
+#
+#    * Redistributions of source code must retain the above copyright
+#      notice, this list of conditions and the following disclaimer.
+#    * Redistributions in binary form must reproduce the above copyright notice,
+#      this list of conditions and the following disclaimer in the documentation
+#      and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+# IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+# USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+from ansible.module_utils._text import to_text, to_native
+from ansible.module_utils.connection import Connection, ConnectionError
+
+try:
+    from lxml.etree import Element, fromstring
+except ImportError:
+    from xml.etree.ElementTree import Element, fromstring
+
+NS_MAP = {'nc': "urn:ietf:params:xml:ns:netconf:base:1.0"}
+
+
+def exec_rpc(module, *args, **kwargs):
+    connection = NetconfConnection(module._socket_path)
+    return connection.execute_rpc(*args, **kwargs)
+
+
+class NetconfConnection(Connection):
+
+    def __init__(self, socket_path):
+        super(NetconfConnection, self).__init__(socket_path)
+
+    def __rpc__(self, name, *args, **kwargs):
+        """Executes the json-rpc and returns the output received
+           from remote device.
+           :name: rpc method to be executed over connection plugin that implements jsonrpc 2.0
+           :args: Ordered list of params passed as arguments to rpc method
+           :kwargs: Dict of valid key, value pairs passed as arguments to rpc method
+
+           For usage refer the respective connection plugin docs.
+        """
+        self.check_rc = kwargs.pop('check_rc', True)
+        self.ignore_warning = kwargs.pop('ignore_warning', True)
+
+        response = self._exec_jsonrpc(name, *args, **kwargs)
+        if 'error' in response:
+            rpc_error = response['error'].get('data')
+            return self.parse_rpc_error(to_native(rpc_error, errors='surrogate_then_replace'))
+
+        return fromstring(to_native(response['result'], errors='surrogate_then_replace'))
+
+    def parse_rpc_error(self, rpc_error):
+        if self.check_rc:
+            error_root = fromstring(rpc_error)
+            root = Element('root')
+            root.append(error_root)
+
+            error_list = root.findall('.//nc:rpc-error', NS_MAP)
+            if not error_list:
+                raise ConnectionError(to_text(rpc_error, errors='surrogate_then_replace'))
+
+            warnings = []
+            for error in error_list:
+                message = error.find('./nc:error-message', NS_MAP).text
+                severity = error.find('./nc:error-severity', NS_MAP).text
+
+                if severity == 'warning' and self.ignore_warning:
+                    warnings.append(message)
+                else:
+                    raise ConnectionError(to_text(rpc_error, errors='surrogate_then_replace'))
+            return warnings