nautobot-plugin-nornir 0.9.6

Nautobot Nornir plugin.

ntc-nautobot-plugin-nornir

A plugin for Nautobot, that intends to be a small shim layer between nornir-nautobot and other plugins. The primary abilities that the plugin provides is a native Nornir ORM based inventory and a credential manager.

As of the writing of this readme, the only plugin leveraging this plugin is the golden-config. However, future plugins are planned, such as the "network importer".

That being said, there is currently little reason to install this plugin by itself, without an enabler, which can be seen represented as the white rectangles inside the yellow rectangle in the diagram above. An enabler could be a Plugin, Job, or another piece of code like a Chatops command.

Installation

If using the installation pattern from the Nautobot Documentation, you will need sudo to the nautobot user before installing so that you install the package into the Nautobot virtual environment.

sudo -iu nautobot

The plugin is available as a Python package in PyPI and can be installed with pip3.

$ pip3 install nautobot-plugin-nornir

To ensure the plugin is automatically re-installed during future upgrades, create a file named local_requirements.txt (or append if it already exists) in the NAUTOBOT_ROOT directory and list the nautobot-plugin-nornir package:

$ echo nautobot-plugin-nornir >> $NAUTOBOT_ROOT/local_requirements.txt

The plugin is compatible with Nautobot 1.0.0 and higher

Once installed, the plugin needs to be enabled in your nautobot_config.py

# In your nautobot_config.py
PLUGINS = ["nautobot_plugin_nornir"]

PLUGINS_CONFIG = {
  "nautobot_plugin_nornir": {
    "nornir_settings": {
      "credentials": "nautobot_plugin_nornir.plugins.credentials.env_vars.CredentialsEnvVars",
      "runner": {
        "plugin": "threaded",
        "options": {
            "num_workers": 20,
        },
      },
    },
  }

Alternatively you can use the CredentialsSettingsVars class to set the username and password via settings.

PLUGINS_CONFIG = {
  "nautobot_plugin_nornir": {
    "nornir_settings": {
      "credentials": "nautobot_plugin_nornir.plugins.credentials.settings_vars.CredentialsSettingsVars",
      "runner": {
        "plugin": "threaded",
        "options": {
            "num_workers": 20,
        },
      },
    },
    "dispatcher_mapping": None,
    "username": "ntc",
    "password": "password123",
    "secret": "password123",
  }
}

The plugin behavior can be controlled with the following list of settings.

Key	Example	Default	Description
nornir_settings	{"nornir_settings": { "credentials": "cred_path"}}	N/A	The expected configuration paramters that Nornir uses, see Nornir documentation.
dispatcher_mapping	{"newos": "dispatcher.newos"}	None	A dictionary in which the key is a platform slug and the value is the import path of the dispatcher in string format
username	ntc	N/A	The username when leveraging the CredentialsSettingsVars credential provider.
password	password123	N/A	The password when leveraging the CredentialsSettingsVars credential provider.
secret	password123	N/A	The secret password when leveraging the CredentialsSettingsVars credential provider, placeholder only, not currently functioning.

Finally, as root, restart Nautobot and the Nautobot worker.

$ sudo systemctl restart nautobot nautobot-worker

Setting dispatcher_mapping

The dispatcher_mapping configuration option can be set to extend or map the platform slug to a proper nornir class.

 {
  "dispatcher_mapping": {
    "newos": "dispatcher.newos",
    "ios": "nornir_nautobot.plugins.tasks.dispatcher.cisco_ios.NautobotNornirDriver",
    "ios_xe": "nornir_nautobot.plugins.tasks.dispatcher.cisco_ios.NautobotNornirDriver",
    "fortinet": "nornir_nautobot.plugins.tasks.dispatcher.default.NetmikoNautobotNornirDriver",
  }
}

The above example demonstrates the following use cases.

• Creating a custom only local dispatcher
• Mapping a user defined and preffered platform slug name to expected driver (e.g. ios -> cisco_ios)
• Overloading platform slug keys, by mapping ios and ios_xe to the same class
• Leveraging the existing "default" Netmiko driver

Plugin developers that leverage the plugin, are recommended to use the get_dispatcher function in nautobot_plugin_nornir.utils file to provide the ability to allow users to define their own mappings as described above.

Inventory

The Nautobot ORM inventory is rather static in nature at this point. The user has the ability to define the default data. The native capabilites include.

• Providing an object called within the obj key that is a Nautobot Device object instance.
• Provide additional keys for hostname, name, id, type, site, role, config_context, and custom_field_data.
• Provide grouping for global, site, role, type, and manufacturer based on their slug.
• Provide credentials for NAPALM and Netmiko.
• Link to the credential class as defined by the nornir_settings['settings'] definition.

Credentials

There is a NautobotORMCredentials class that describes what methods a Nautobot Nornir credential class should have.

class NautobotORMCredentials:
    """Abstract Credentials Class designed to work with Nautobot ORM."""

    def get_device_creds(self, device):
        """Return the credentials for a given device.

        Args:
            device (dcim.models.Device): Nautobot device object

        Return:
            username (string):
            password (string):
            secret (string):
        """
        return (None, None, None)

    def get_group_creds(self, group_name):
        """Return the credentials for a given group.

        Args:
            group_name (string): Name of the group

        Return:
            string: username
            string: password
            string: secret
        """
        return (None, None, None)

Any custom credential class should inherit from this model and provide get_device_creds and/or get_group_creds methods. Currently, only the get_device_creds is used. Building your own custom credential class allows users to control their own credential destiny. As an example, a user could integrate with their own vaulting system, and obtain credentials that way. To provide a simple but concrete example.

class CustomNautobotORMCredentials(NautobotORMCredentials):

    def get_device_creds(self, device):
        if device.startswith('csr'):
            return ("cisco", "cisco123", None)
        return ("net-admin", "ops123", None)

You would have to set your nornir_settings['credentials'] path to your custom class, such as local_plugin.creds.CustomNautobotORMCredentials.

Out of the box, users have access to the nautobot_plugin_nornir.plugins.credentials.settings_vars.CredentialsSettingsVars and nautobot_plugin_nornir.plugins.credentials.env_vars.CredentialsEnvVars class. This CredentialsEnvVars class simply leverages the environment variables NAPALM_USERNAME, NAPALM_PASSWORD, and DEVICE_SECRET.

Note: DEVICE_SECRET does not currently work.

The environment variable must be accessible on the web service. This often means simply exporting the environment variable will not suffice, but instead requiring users to update the nautobot.service file, however this will ultimately depend on your own setup. Environment variables are distinctively not nautobot configuration parameters (in naubot_config.py), if that does not makes sense, expect to see authentication issues.

[Service]
Environment="NAPALM_USERNAME=ntc"
Environment="NAPALM_PASSWORD=password123"
Environment="DEVICE_SECRET=password123"

Contributing

Pull requests are welcomed and automatically built and tested against multiple version of Python and multiple version of Nautobot through TravisCI.

The project is packaged with a light development environment based on docker-compose to help with the local development of the project and to run the tests within TravisCI.

The project is following Network to Code software development guideline and is leveraging:

• Black, Pylint, Bandit and pydocstyle for Python linting and formatting.
• Django unit test to ensure the plugin is working properly.

CLI Helper Commands

The project is coming with a CLI helper based on invoke to help setup the development environment. The commands are listed below in 3 categories dev environment, utility and testing.

Each command can be executed with invoke <command>. All commands support the arguments --nautobot-ver and --python-ver if you want to manually define the version of Python and Nautobot to use. Each command also has its own help invoke <command> --help

Local dev environment

  build            Build all docker images.
  debug            Start Nautobot and its dependencies in debug mode.
  destroy          Destroy all containers and volumes.
  restart          Restart Nautobot and its dependencies.
  start            Start Nautobot and its dependencies in detached mode.
  stop             Stop Nautobot and its dependencies.

Utility

  cli              Launch a bash shell inside the running Nautobot container.
  create-user      Create a new user in django (default: admin), will prompt for password.
  makemigrations   Run Make Migration in Django.
  nbshell          Launch a nbshell session.

Testing

  bandit           Run bandit to validate basic static code security analysis.
  black            Run black to check that Python files adhere to its style standards.
  flake8           This will run flake8 for the specified name and Python version.
  pydocstyle       Run pydocstyle to validate docstring formatting adheres to NTC defined standards.
  pylint           Run pylint code analysis.
  tests            Run all tests for this plugin.
  unittest         Run Django unit tests for the plugin.

Questions

For any questions or comments, please check the FAQ first and feel free to swing by the Network to Code slack channel (channel #networktocode). Sign up here