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/network.py

@@ -0,0 +1,203 @@
+# 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.
+#
+# Copyright (c) 2015 Peter Sprygada, <psprygada@ansible.com>
+#
+# 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.
+
+import traceback
+
+from ansible.module_utils.basic import AnsibleModule
+from ansible.module_utils.basic import env_fallback
+from ansible.module_utils.network.common.parsing import Cli
+from ansible.module_utils._text import to_native
+from ansible.module_utils.six import iteritems
+
+
+NET_TRANSPORT_ARGS = dict(
+    host=dict(required=True),
+    port=dict(type='int'),
+
+    username=dict(fallback=(env_fallback, ['ANSIBLE_NET_USERNAME'])),
+    password=dict(no_log=True, fallback=(env_fallback, ['ANSIBLE_NET_PASSWORD'])),
+    ssh_keyfile=dict(fallback=(env_fallback, ['ANSIBLE_NET_SSH_KEYFILE']), type='path'),
+
+    authorize=dict(default=False, fallback=(env_fallback, ['ANSIBLE_NET_AUTHORIZE']), type='bool'),
+    auth_pass=dict(no_log=True, fallback=(env_fallback, ['ANSIBLE_NET_AUTH_PASS'])),
+
+    provider=dict(type='dict', no_log=True),
+    transport=dict(choices=list()),
+
+    timeout=dict(default=10, type='int')
+)
+
+NET_CONNECTION_ARGS = dict()
+
+NET_CONNECTIONS = dict()
+
+
+def _transitional_argument_spec():
+    argument_spec = {}
+    for key, value in iteritems(NET_TRANSPORT_ARGS):
+        value['required'] = False
+        argument_spec[key] = value
+    return argument_spec
+
+
+def to_list(val):
+    if isinstance(val, (list, tuple)):
+        return list(val)
+    elif val is not None:
+        return [val]
+    else:
+        return list()
+
+
+class ModuleStub(object):
+    def __init__(self, argument_spec, fail_json):
+        self.params = dict()
+        for key, value in argument_spec.items():
+            self.params[key] = value.get('default')
+        self.fail_json = fail_json
+
+
+class NetworkError(Exception):
+
+    def __init__(self, msg, **kwargs):
+        super(NetworkError, self).__init__(msg)
+        self.kwargs = kwargs
+
+
+class Config(object):
+
+    def __init__(self, connection):
+        self.connection = connection
+
+    def __call__(self, commands, **kwargs):
+        lines = to_list(commands)
+        return self.connection.configure(lines, **kwargs)
+
+    def load_config(self, commands, **kwargs):
+        commands = to_list(commands)
+        return self.connection.load_config(commands, **kwargs)
+
+    def get_config(self, **kwargs):
+        return self.connection.get_config(**kwargs)
+
+    def save_config(self):
+        return self.connection.save_config()
+
+
+class NetworkModule(AnsibleModule):
+
+    def __init__(self, *args, **kwargs):
+        connect_on_load = kwargs.pop('connect_on_load', True)
+
+        argument_spec = NET_TRANSPORT_ARGS.copy()
+        argument_spec['transport']['choices'] = NET_CONNECTIONS.keys()
+        argument_spec.update(NET_CONNECTION_ARGS.copy())
+
+        if kwargs.get('argument_spec'):
+            argument_spec.update(kwargs['argument_spec'])
+        kwargs['argument_spec'] = argument_spec
+
+        super(NetworkModule, self).__init__(*args, **kwargs)
+
+        self.connection = None
+        self._cli = None
+        self._config = None
+
+        try:
+            transport = self.params['transport'] or '__default__'
+            cls = NET_CONNECTIONS[transport]
+            self.connection = cls()
+        except KeyError:
+            self.fail_json(msg='Unknown transport or no default transport specified')
+        except (TypeError, NetworkError) as exc:
+            self.fail_json(msg=to_native(exc), exception=traceback.format_exc())
+
+        if connect_on_load:
+            self.connect()
+
+    @property
+    def cli(self):
+        if not self.connected:
+            self.connect()
+        if self._cli:
+            return self._cli
+        self._cli = Cli(self.connection)
+        return self._cli
+
+    @property
+    def config(self):
+        if not self.connected:
+            self.connect()
+        if self._config:
+            return self._config
+        self._config = Config(self.connection)
+        return self._config
+
+    @property
+    def connected(self):
+        return self.connection._connected
+
+    def _load_params(self):
+        super(NetworkModule, self)._load_params()
+        provider = self.params.get('provider') or dict()
+        for key, value in provider.items():
+            for args in [NET_TRANSPORT_ARGS, NET_CONNECTION_ARGS]:
+                if key in args:
+                    if self.params.get(key) is None and value is not None:
+                        self.params[key] = value
+
+    def connect(self):
+        try:
+            if not self.connected:
+                self.connection.connect(self.params)
+                if self.params['authorize']:
+                    self.connection.authorize(self.params)
+                self.log('connected to %s:%s using %s' % (self.params['host'],
+                         self.params['port'], self.params['transport']))
+        except NetworkError as exc:
+            self.fail_json(msg=to_native(exc), exception=traceback.format_exc())
+
+    def disconnect(self):
+        try:
+            if self.connected:
+                self.connection.disconnect()
+            self.log('disconnected from %s' % self.params['host'])
+        except NetworkError as exc:
+            self.fail_json(msg=to_native(exc), exception=traceback.format_exc())
+
+
+def register_transport(transport, default=False):
+    def register(cls):
+        NET_CONNECTIONS[transport] = cls
+        if default:
+            NET_CONNECTIONS['__default__'] = cls
+        return cls
+    return register
+
+
+def add_argument(key, value):
+    NET_CONNECTION_ARGS[key] = value