Add initial napalm connection plugin (#45224)

* Add initial napalm connection plugin

* Fix review comments

lib/ansible/plugins/connection/__init__.py

@@ -360,7 +360,8 @@ class NetworkConnectionBase(ConnectionBase):
         initialize implementation plugin options
         '''
         for plugin in self._implementation_plugins:
-            plugin.set_options(task_keys=task_keys, var_options=var_options, direct=direct)
+            if hasattr(plugin, 'set_options'):
+                plugin.set_options(task_keys=task_keys, var_options=var_options, direct=direct)
 
     def _update_connection_state(self):
         '''

lib/ansible/plugins/connection/napalm.py

@@ -0,0 +1,198 @@
+# (c) 2018 Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+
+DOCUMENTATION = """
+---
+author: Ansible Networking Team
+connection: napalm
+short_description: Provides persistent connection using NAPALM
+description:
+  - This connection plugin provides connectivity to network devices using
+    the NAPALM network device abstraction library.  This library requires
+    certain features to be enabled on network devices depending on the
+    destination device operating system.  The connection plugin requires
+    C(napalm) to be installed locally on the Ansible controller.
+version_added: "2.8"
+requirements:
+  - napalm
+options:
+  host:
+    description:
+      - Specifies the remote device FQDN or IP address to establish the SSH
+        connection to.
+    default: inventory_hostname
+    vars:
+      - name: ansible_host
+  port:
+    type: int
+    description:
+      - Specifies the port on the remote device that listens for connections
+        when establishing the SSH connection.
+    default: 22
+    ini:
+      - section: defaults
+        key: remote_port
+    env:
+      - name: ANSIBLE_REMOTE_PORT
+    vars:
+      - name: ansible_port
+  network_os:
+    description:
+      - Configures the device platform network operating system.  This value is
+        used to load a napalm device abstraction.
+    vars:
+      - name: ansible_network_os
+  remote_user:
+    description:
+      - The username used to authenticate to the remote device when the SSH
+        connection is first established.  If the remote_user is not specified,
+        the connection will use the username of the logged in user.
+      - Can be configured from the CLI via the C(--user) or C(-u) options.
+    ini:
+      - section: defaults
+        key: remote_user
+    env:
+      - name: ANSIBLE_REMOTE_USER
+    vars:
+      - name: ansible_user
+  password:
+    description:
+      - Configures the user password used to authenticate to the remote device
+        when first establishing the SSH connection.
+    vars:
+      - name: ansible_password
+      - name: ansible_ssh_pass
+  private_key_file:
+    description:
+      - The private SSH key or certificate file used to authenticate to the
+        remote device when first establishing the SSH connection.
+    ini:
+      - section: defaults
+        key: private_key_file
+    env:
+      - name: ANSIBLE_PRIVATE_KEY_FILE
+    vars:
+      - name: ansible_private_key_file
+  timeout:
+    type: int
+    description:
+      - Sets the connection time, in seconds, for communicating with the
+        remote device.  This timeout is used as the default timeout value for
+        commands when issuing a command to the network CLI.  If the command
+        does not return in timeout seconds, an error is generated.
+    default: 120
+  host_key_auto_add:
+    type: boolean
+    description:
+      - By default, Ansible will prompt the user before adding SSH keys to the
+        known hosts file. By enabling this option, unknown host keys will
+        automatically be added to the known hosts file.
+      - Be sure to fully understand the security implications of enabling this
+        option on production systems as it could create a security vulnerability.
+    default: False
+    ini:
+      - section: paramiko_connection
+        key: host_key_auto_add
+    env:
+      - name: ANSIBLE_HOST_KEY_AUTO_ADD
+  persistent_connect_timeout:
+    type: int
+    description:
+      - Configures, in seconds, the amount of time to wait when trying to
+        initially establish a persistent connection.  If this value expires
+        before the connection to the remote device is completed, the connection
+        will fail.
+    default: 30
+    ini:
+      - section: persistent_connection
+        key: connect_timeout
+    env:
+      - name: ANSIBLE_PERSISTENT_CONNECT_TIMEOUT
+  persistent_command_timeout:
+    type: int
+    description:
+      - Configures, in seconds, the amount of time to wait for a command to
+        return from the remote device.  If this timer is exceeded before the
+        command returns, the connection plugin will raise an exception and
+        close.
+    default: 10
+    ini:
+      - section: persistent_connection
+        key: command_timeout
+    env:
+      - name: ANSIBLE_PERSISTENT_COMMAND_TIMEOUT
+    vars:
+      - name: ansible_command_timeout
+"""
+
+from ansible.errors import AnsibleConnectionFailure, AnsibleError
+from ansible.plugins.connection import NetworkConnectionBase
+
+try:
+    from napalm import get_network_driver
+    from napalm.base import ModuleImportError
+    HAS_NAPALM = True
+except ImportError:
+    raise AnsibleError(
+        'Napalm is required to use the napalm connection type.\n'
+        'Please run pip install napalm'
+    )
+
+try:
+    from __main__ import display
+except ImportError:
+    from ansible.utils.display import Display
+    display = Display()
+
+
+class Connection(NetworkConnectionBase):
+    """Napalm connections"""
+
+    transport = 'napalm'
+    has_pipelining = False
+
+    def __init__(self, play_context, new_stdin, *args, **kwargs):
+        super(Connection, self).__init__(play_context, new_stdin, *args, **kwargs)
+
+        self.napalm = None
+
+    def _connect(self):
+        super(Connection, self)._connect()
+
+        if not self.connected:
+            if not self._network_os:
+                raise AnsibleConnectionFailure(
+                    'Unable to automatically determine host network os. Please '
+                    'manually configure ansible_network_os value for this host'
+                )
+            display.display('network_os is set to %s' % self._network_os, log_only=True)
+
+            try:
+                driver = get_network_driver(self._network_os)
+            except ModuleImportError:
+                raise AnsibleConnectionFailure('Failed to import napalm driver for {0}'.format(self._network_os))
+
+            host = self.get_option('host')
+            self.napalm = driver(
+                hostname=host,
+                username=self.get_option('remote_user'),
+                password=self.get_option('password'),
+                timeout=self.get_option('persistent_command_timeout'),
+            )
+
+            self.napalm.open()
+
+            self._implementation_plugins.append(self.napalm)
+            display.vvvv('created napalm device for network_os %s' % self._network_os, host=host)
+            self._connected = True
+
+    def close(self):
+        if self.napalm:
+            self.napalm.close()
+            self.napalm = None
+
+        super(Connection, self).close()