.. image:: ../../_static/openl2m_logo.png

========================
Implementing New Drivers
========================

Book Keeping
============

All drivers need to implement various interfaces, as described below and in the `Connector() class. <connector>`

Additionally, in order for the web interface to show these changes (if succesful),
drivers need to call "bookkeeping" calls in the base Connector() class.

If you inherit directly from Connector(), you can call these with super().set_xyz()

If you have multiple inheritance in in your driver (DriverB, inherits from DriversA which inherits from Connector()),
you should use the notation *Connector.set_xyz(self=self, <other params>)*


Supporting a new vendor device - SNMP
=====================================

**Create Vendor Sub-directory**

In openl2m/switches/connect/snmp/, create a vendor sub-directory.

In this folder you need a __init__.py (copy from somewhere else :-)), and a minimum file called connector.py, and likely constants.py

In connector.py, create your new driver class that inherits from the SnmpConnector() class. Call the class SnmpConnector*VendorName*

Override whatever function are needed (see the samples in vendor/cisco, vendor/procurve and vendor/comware)


**Use The New Driver Class***

Driver classes are loaded from openl2m/switches/connect/connect.py

* Include your driver to connect.py around line 40. E.g.:

.. code-block:: bash

    from switches.connect.snmp.vendors.procurve.constants import *
    from switches.connect.snmp.vendors.procurve.snmp import SnmpConnectorProcurve

* Now reference your drive in the get_connection_object() function  around line 90,
  add code to call the new vendor class when that vendor is detected. E.g.:

.. code-block:: bash

    if enterprise == ENTERPRISE_ID_HP:
      return SnmpConnectorProcurve(request, group, switch)


Supporting a new vendor device - Custom
=======================================

You can also extend OpenL2M for vendors that support their own API's, such as REST. An example of this Aruba AOS-CX
devices. To add a customer driver, follow these steps:

**Add  Connector Type**

in /openl2m/switches/constants, add lines similar to the following to the connector type definition:

.. code-block:: bash

  CONNECTOR_TYPE_AOSCX = 2
  CONNECTOR_TYPE_CHOICES = [
      ..
      [CONNECTOR_TYPE_AOSCX, 'Aruba AOS-CX'],
  ]

After this, you will need to create a new Django "migration" to handle this data field update:

.. code-block:: bash

  python3 manage.py makemigrations


**Create the Custom Driver**

In openl2m/switches/connect/, create a sub-directory representing your connector type. Eg. "aruba_aoscx".
Use all lower case, and underscores only.

In this folder you need a __init__.py (copy from somewhere else :-)),
and a minimum file called connector.py, and likely constants.py

In connector.py, create your new driver class that inherits from the base Connector() class.
Call the class *YourTypeName*Connector()*. Eg. AosCxConnector()

Implement the functions needed to support this device class. At a minimum, you need to create

*def get_my_basic_info(self)* to load interfaces, etc.

Optionally, *def get_my_client_data(self)* is needed if you want to provide ethernet and lldp neighbor data.


**Call the Customer Driver**

Driver classes are loaded from openl2m/switches/connect/connect.py

* Include your driver to connect.py around line 40. E.g.:

.. code-block:: bash

    from switches.connect.aruba_aoscx.constants import *
    from switches.connect.aruba_aoscx.connector import AosCxConnector

* Now reference your drive in the get_connection_object() function around line 110:

.. code-block:: bash

  elif switch.connector_type == CONNECTOR_TYPE_ARUBA_AOSCX:
    connection = AosCxConnector(request, group, switch)


**Validate New Devices Using This Driver**

You may need to edit the *clean()* function of the *Switch(models.Model)* class in switches/models.py
to facilitate checking for the right settings. E.g. an API driver will need a credential profile.


Customizing the Information Tab
===============================

In your vendor implementation, you can add custom data to the Information tab by implementing
the *_get_vendor_data()* method in your class. Collect your data, then call
"add_vendor_data(category_name, item_name, item_value)" to add data. You can read whatever
specific MIB counters you like, or any other data you can get your hands on via e.g. SSH/Netmiko

Here is a hard-coded example. See *snmp/procurve* and *snmp/comware* for additional examples:

.. code-block:: bash

  def _get_vendor_data(self):
      """
      Implement vendor-specific data, add whatever you want here.
      This shows in the "Information" tab
      """
      self.add_vendor_data('Cat 1', 'Item 1', "some data")
      self.add_vendor_data('Cat 1', 'CPU Temp', "75.4 C")
      self.add_vendor_data('Cat 1', 'Fan Speed', "1400rpm")
      self.add_vendor_data('Memory Stats', 'Item 1', "some data")
      self.add_vendor_data('Memory Stats', 'CPU Temp', "75.4 C")
      self.add_vendor_data('Memory Stats', 'Fan Speed', "1400rpm")

Customizing SSH/CLI commands
============================

If your device needs to change how CLI commands are run (ie. not use standard SSH),
your driver needs to implement (override) the *Connector()._execute_command()* function.

See more at :doc:`implementing SSH<netmiko/index>`.