ncclient:NETCONF Python client

============================================

**TODO**

release = '0.2'

**TODO**

Here it is discussed how new transport mappings and new operations can be added.

.. data:: CAPABILITIES

    List of URI strings representing the client's capabilities. This is used during the initial

    capability exchange. Modify this if you need to announce some capability not already included.

.. data:: OPERATIONS

    Dictionary of method names and corresponding `~ncclient.operations.RPC` classes. `Manager` uses

    this to lookup operations, e.g. "get_config" is mapped to `ncclient.operations.GetConfig`. It

    is thus possible to add additional operations to the `Manager` API.

    Initializes a NETCONF session over SSH, and creates a connected `Manager` instance. *host* must

    be specified, all the other arguments are optional and depend on the kind of host key

    verification and user authentication you want to complete.

    For the purpose of host key verification, on -NIX systems a user's :file:`~/.ssh/known_hosts`

    file is automatically considered. The *unknown_host_cb* argument specifies a callback that will

    be invoked when the server's host key cannot be verified. See

    First, ``publickey`` authentication is attempted. If a specific *key_filename* is specified, it

    will be loaded and authentication attempted using it. If *allow_agent* is :const:`True` and an

    SSH agent is running, the keys provided by the agent will be tried. If *look_for_keys* is

    :const:`True`, keys in the :file:`~/.ssh/id_rsa` and :file:`~.ssh/id_dsa` will be tried. In case

    an encrypted key file is encountered, the *password* argument will be used as a decryption

    passphrase.

    If ``publickey`` authentication fails and the *password* argument has been supplied,

    ``password`` / ``keyboard-interactive`` SSH authentication will be attempted.

    :param unknown_host_cb: optional; callback that is invoked when host key verification fails

    :param username: username to authenticate with, if not specified the username of the logged-in

                       user is used

    :param password: password for ``password`` authentication or passphrase for decrypting

                       private key files

Exposes an API for RPC operations as method calls. The return type of these methods depends on

whether we are is in :attr:`asynchronous or synchronous mode <ncclient.manager.Manager.async_mode>`.

In synchronous mode replies are awaited and the corresponding `~ncclient.operations.RPCReply` object

is returned. Depending on the :attr:`exception raising mode <ncclient.manager.Manager.raise_mode>`,

an *rpc-error* in the reply may be raised as :exc:`RPCError` exceptions.

However in asynchronous mode, operations return immediately with an `~ncclient.operations.RPC`

object. Error handling and checking for whether a reply has been received must be dealt with

manually. See the `~ncclient.operations.RPC` documentation for details.

Note that in case of the *get* and *get-config* operations, the reply is an instance of

`~ncclient.operations.GetReply` which exposes the additional attributes

:attr:`~ncclient.operations.GetReply.data` (as `~xml.etree.ElementTree.Element`) and

:attr:`~ncclient.operations.GetReply.data_xml` (as `string`), which are of primary interest in case

of these operations.

Presence of capabilities is verified to the extent possible, and you can expect a

:exc:`~ncclient.operations.MissingCapabilityError` if something is amiss. In case of transport-layer

errors, e.g. unexpected session close, :exc:`~ncclient.transport.TransportError` will be raised.

        :param filter: portions of the device configuration to retrieve (by default entire configuration is retrieved)

        :type filter: :ref:`filter_params`

        :param config: configuration (must be rooted in *<config> .. </config>*)

        :type config: `string` or `~xml.etree.ElementTree.Element`

        Create or replace an entire configuration datastore with the contents of another complete

        configuration datastore. 

        :param source: configuration datastore to use as the source of the copy operation or *<config>* element containing the configuration subtree to copy

        :type source: :ref:`srctarget_params`

        :param target: configuration datastore to use as the destination of the copy operation

        :type target: :ref:`srctarget_params`

        :param target: name or URL of configuration datastore to delete

        :type: :ref:`srctarget_params`

        :param target: name of configuration datastore to lock

        :type target: `string`

        :param filter: portions of the device configuration to retrieve (by default entire configuration is retrieved)

        :type filter: :ref:`filter_params`

        Request graceful termination of the NETCONF session, and also close the transport.

        :param session_id: session identifier of the NETCONF session to be terminated

    .. method:: commit([confirmed=False, timeout=None])

        Commit the candidate configuration as the device's new current configuration. Depends on the

        *:candidate* capability.

        A confirmed commit (i.e. if *confirmed* is :const:`True`) is reverted if there is no

        followup commit within the *timeout* interval. If no timeout is specified the confirm

        timeout defaults to 600 seconds (10 minutes). A confirming commit may have the *confirmed*

        parameter but this is not required. Depends on the *:confirmed-commit* capability.

        :param confirmed: whether this is a confirmed commit

        :type confirmed: `bool`

        :param timeout: confirm timeout in seconds

        :type timeout: `int`

    .. method:: discard_changes()

        Revert the candidate configuration to the currently running configuration. Any uncommitted

        changes are discarded.

    .. method:: validate(source)

        Validate the contents of the specified configuration.

        :param source: name of the configuration datastore being validated or *<config>* element containing the configuration subtree to be validated

        :type source: :ref:`srctarget_params`

        Specify which errors are raised as :exc:`~ncclient.operations.RPCError` exceptions.

        Valid values:

        `~ncclient.capabilities.Capabilities` object representing the client's capabilities.

        `~ncclient.capabilities.Capabilities` object representing the server's capabilities.

        *session-id* assigned by the NETCONF server.

        Bolean value indicating whether currently connected to the NETCONF server.

---------------------------

Some parameters can take on different types to keep the interface simple.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Where an method takes a *source* or *target* argument, usually a datastore name or URL is expected.

The latter depends on the ``:url`` capability and on whether the specific URL scheme is supported.

Either must be specified as a `string`. For example, ``"running"``,

``"ftp://user:pass@host/config"``.

If the source may be a *<config>* element, e.g. as allowed for the *validate* RPC, it can also be

specified as an XML string or an `~xml.etree.ElementTree.Element` object.

^^^^^^^^^^^^^^^^^

    * For ``"xpath"`` the *criteria* should be a `string` containing the XPath expression.

* A *<filter>* element as an XML string or an `~xml.etree.ElementTree.Element` object.

    "*<commit>* RPC. Depends on the *:candidate* capability, and the *:confirmed-commit* "

"Methods for creating, parsing, and dealing with XML and ElementTree objects."

class XMLError(NCClientError): pass

    "Checks if the root element of an XML document or Element meets the supplied criteria."

new_ele = lambda tag, attrs={}, **extra: ET.Element(tag, attrs, **extra)

sub_ele = lambda parent, tag, attrs={}, **extra: ET.SubElement(parent, tag, attrs, **extra)

      version='0.2',

      url="http://schmizz.net/ncclient/",