FakeNOS Service Get Nornir Inventory Task

task api name: get_nornir_inventory

The FakeNOS service get_nornir_inventory task builds a Nornir-compatible inventory from the hosts running in one or all FakeNOS virtual networks. The resulting inventory can be fed directly into the Nornir Service to run automation tasks against simulated devices.

FakeNOS Get Nornir Inventory Task Overview

The get_nornir_inventory task provides the following features:

• Automatic Inventory Generation: Queries running FakeNOS networks and maps host data (name, port, platform, credentials) to the Nornir inventory format.
• Localhost Binding: All generated hosts use 127.0.0.1 as their hostname because FakeNOS SSH servers listen on the local machine.
• Group Assignment: Optionally assign one or more Nornir group names to every host in the generated inventory.
• Network Scoping: Optionally limit inventory generation to a single named network.

FakeNOS Get Nornir Inventory Task Arguments

Argument	Type	Default	Description
network	str or None	None	Name of a specific FakeNOS network to build inventory for. If None, hosts from all running networks are included.
groups	str, list, or None	None	A group name or list of Nornir group names to assign to every generated host.

FakeNOS Get Nornir Inventory Task Return Data

The task returns a dict with a single hosts key. The value is a dict keyed by host name.

Field	Type	Description
hostname	str	Always 127.0.0.1 — FakeNOS SSH servers listen on localhost.
port	int	TCP port assigned to this host in the FakeNOS inventory.
platform	str	NOS platform name (e.g. RouterOS). May be None if not set.
username	str	SSH username for the simulated device.
password	str	SSH password for the simulated device.
groups	list	List of Nornir group names. Empty list if groups was not specified.

FakeNOS Get Nornir Inventory Command Shell Reference

NorFab shell supports these command options for Netbox create_prefix task:

nf#man tree fakenos.get-nornir-inventory

R - required field, M - supports multiline input, D - dynamic key

root
└── fakenos:    FakeNOS service
    └── get-nornir-inventory:    Get Nornir inventory from FakeNOS networks
        ├── network:    FakeNOS network name to get Nornir inventory for
        ├── groups:    List of groups to include in host's inventory
        ├── timeout:    Job timeout
        ├── workers:    Filter workers to target, default 'all'
        ├── verbose-result:    Control output details, default 'False'
        ├── progress:    Display progress events, default 'True'
        └── nowait:    Do not wait for job to complete, default 'False'
nf#

Python API Reference

Retrieve and construct Nornir inventory from FakeNOS data.

Parameters:

Name	Type	Description	Default
job	Job	NorFab Job object containing relevant metadata	required
network	Union[str, None]	Name of the FakeNOS network to build inventory for. If None, inventory is built for all networks.	None
groups	Union[None, list]	List of Nornir group names to assign to every host.	None

Returns:

Name	Type	Description
Result	Result	A Result object whose result attribute is a dict with a hosts key containing hostname-keyed Nornir host entries.

Source code in norfab\workers\fakenos_worker\nornir_inventory_tasks.py

@Task(input=GetNornirInventoryInput, fastapi={"methods": ["GET"]})
def get_nornir_inventory(
    self,
    job: Job,
    network: Union[str, None] = None,
    groups: Union[None, list] = None,
) -> Result:
    """
    Retrieve and construct Nornir inventory from FakeNOS data.

    Args:
        job: NorFab Job object containing relevant metadata
        network: Name of the FakeNOS network to build inventory for.
            If None, inventory is built for all networks.
        groups: List of Nornir group names to assign to every host.

    Returns:
        Result: A Result object whose ``result`` attribute is a dict with
            a ``hosts`` key containing hostname-keyed Nornir host entries.
    """
    groups = groups or []
    hosts = {}
    inventory = {"hosts": hosts}
    ret = Result(task=f"{self.name}:get_nornir_inventory", result=inventory)

    # retrieve network details from FakeNOS
    inspect = self.inspect_networks(job=job, network=network, details=True)

    if inspect.failed:
        ret.failed = True
        ret.errors = inspect.errors
        return ret

    # if a specific network was requested but not found, fail
    if network and not inspect.result:
        ret.failed = True
        ret.errors = [f"Network '{network}' not found"]
        return ret

    # FakeNOS listens on localhost
    hostname = "127.0.0.1"

    for net_name, net_info in inspect.result.items():
        for host in net_info.get("hosts", []):
            host_name = host.get("name")
            if not host_name:
                continue

            hosts[host_name] = {
                "hostname": hostname,
                "port": host.get("port"),
                "platform": host.get("platform"),
                "username": host.get("username"),
                "password": host.get("password"),
                "groups": groups,
            }

            log.info(
                f"{self.name} - added '{host_name}' from network '{net_name}' "
                f"to Nornir inventory, port {host.get('port')}, "
                f"platform {host.get('platform')})"
            )

    return ret