doc/developer: adding a CLI node: mention frr-reload.py and VTY_PUSH_XPATH

Signed-off-by: G. Paul Ziemba <paulz@labn.net>
This commit is contained in:
G. Paul Ziemba 2021-09-03 12:23:45 -07:00
parent c6a3a68548
commit d3bb30f588

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@ -777,6 +777,7 @@ To add a new CLI node, you should:
- call ``install_node()`` in the relevant daemon
- define and install the new node in vtysh
- define corresponding node entry commands in daemon and vtysh
- add a new entry to the ``ctx_keywords`` dictionary in ``tools/frr-reload.py``
Defining the numerical node constant
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -844,6 +845,9 @@ Defining corresponding node entry commands in daemon and vtysh
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The command that descends into the new node is typically programmed
with ``VTY_PUSH_CONTEXT`` or equivalent in the daemon's CLI handler function.
(If the CLI has been updated to use the new northbound architecture,
``VTY_PUSH_XPATH`` is used instead.)
In vtysh, you must implement a corresponding node change so that vtysh
tracks the daemon's movement through the node tree.
@ -852,9 +856,9 @@ to replicate their parsing in vtysh, the node-descent function in the
daemon must be blocked from this replication so that a hand-coded
skeleton can be written in ``vtysh.c``.
Accordingly, use one of the ``*_NOSH`` macros such as ``DEFUN_NOSH`` or
``DEFPY_NOSH`` for the daemon's node-descent CLI definition, and use
``DEFUNSH`` in ``vtysh.c`` for the vtysh equivalent.
Accordingly, use one of the ``*_NOSH`` macros such as ``DEFUN_NOSH``,
``DEFPY_NOSH``, or ``DEFUN_YANG_NOSH`` for the daemon's node-descent
CLI definition, and use ``DEFUNSH`` in ``vtysh.c`` for the vtysh equivalent.
.. seealso:: :ref:`vtysh-special-defuns`
@ -876,6 +880,22 @@ Examples:
}
``ripd_whatever.c``
.. code-block:: c
DEFPY_YANG_NOSH(my_new_node,
my_new_node_cmd,
"my-new-node foo",
"New Thing\n"
"A foo\n")
{
[...]
VTY_PUSH_XPATH(MY_NEW_NODE, xbar);
[...]
}
``vtysh.c``
.. code-block:: c
@ -893,6 +913,24 @@ Examples:
install_element(CONFIG_NODE, &my_new_node_cmd);
Adding a new entry to the ``ctx_keywords`` dictionary
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
In file ``tools/frr-reload.py``, the ``ctx_keywords`` dictionary
describes the various node relationships.
Add a new node entry at the appropriate level in this dictionary.
.. code-block:: python
ctx_keywords = {
[...]
"key chain ": {
"key ": {}
},
[...]
"my-new-node": {},
[...]
}
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