lab-2.md

Lab 2 - Using telemetry data programatically

The second part of the lab consist of developing a series of scripts to interact and manipulate the collected and enriched telemetry data in a CLI application.

For this reason we have the example CLI app sauron.py that has commands for each task of this section to give example of how these tasks can be completed.

The python script sauron.py uses typer with rich as dependency to create a beautiful CLI app. It also comes with a python client to interact with Prometheus and Nautobot. In order to install them:

# Install dependencies
pip install -r requeriments.txt

Tasks

1- Prints interfaces High on bandwidth usage on a network device based on a specific threshold

Solution

See command get_links_high_on_in_bw in sauron.py. Here is a snippet:

@app.command()
def get_links_high_on_in_bw(
    device: Optional[str] = typer.Option("", help="Network device or regular expression for multiple devices"),
    device_role: Optional[str] = typer.Option("", help="Role fo the device(s) in the network topology"),
    threshold: float = typer.Option(1000.0, help="Bandwidth threshold on bits per second"),
):
    typer.echo("Getting links with Bandwidth higher than threshold")
    # Prepare the labels to help filtering out the latest metrics
    query = f'rate(interface_in_octets{{device=~"{device}"}}[2m])*8 > {threshold}'

    # Get a list of all the latest metrics that matches the name and label set
    prom = PrometheusConnect(url=prom_url["url"], disable_ssl=True)
    results = prom.custom_query(query=query)
    if not results:
        typer.echo(message="No results returned :(")
        raise typer.Exit(1)

    # Print out the results
    for metric in results:
        _role = metric["metric"]["device_role"]
        _device = metric["metric"]["device"]
        _interface = metric["metric"]["interface"]
        _traffic = sizeof_fmt(float(metric["value"][-1]))
        typer.echo(message=f"Role: {device_role} - device: {_device} - interface: {_interface} => Traffic IN: {_traffic}")
    return

Try it out!

python sauron.py --prometheus-host http://localhost:9091 get-links-high-on-in-bw --device netpanda-jcy-bb-01

2- Allow to show more network devices by using filters like device_role or region

Solution

For this query, we added a device_role parameter which creates a slightly different query that can bring the information of multiple devices as well.

@app.command()
def get_links_high_on_in_bw(
    device: Optional[str] = typer.Option("", help="Network device or regular expression for multiple devices"),
    device_role: Optional[str] = typer.Option("", help="Role fo the device(s) in the network topology"),
    threshold: float = typer.Option(1000.0, help="Bandwidth threshold on bits per second"),
):
    typer.echo("Getting links with Bandwidth higher than threshold")
    # Prepare the labels to help filtering out the latest metrics
    query = ""
    if device:
        query = f'rate(interface_in_octets{{device=~"{device}"}}[2m])*8 > {threshold}'
    if device_role:
        query = f'rate(interface_in_octets{{device_role="{device_role}"}}[2m])*8 > {threshold}'
    if not query:
        typer.echo(message="No query generated :(")
        raise typer.Exit(1)

    # Get a list of all the latest metrics that matches the name and label set
    prom = PrometheusConnect(url=prom_url["url"], disable_ssl=True)
    results = prom.custom_query(query=query)
    if not results:
        typer.echo(message="No results returned :(")
        raise typer.Exit(1)

    # Print out the results
    for metric in results:
        _role = metric["metric"]["device_role"]
        _device = metric["metric"]["device"]
        _interface = metric["metric"]["interface"]
        _traffic = sizeof_fmt(float(metric["value"][-1]))
        typer.echo(message=f"Role: {device_role} - device: {_device} - interface: {_interface} => Traffic IN: {_traffic}")
    return

Try it out!

python sauron.py --prometheus-host http://localhost:9091 get-links-high-on-in-bw --device-role backbone

3- Retrieve BGP state for device or BGP neighbor

Solution

Similar to the previous one.

@app.command()
def get_bgp_state(
    neighbor: str = typer.Option("", help="BGP neighbor"),
    device: str = typer.Option("", help="Network device"),
):
    # Prepare the labels to help filtering out the latest metrics
    labelset = {}
    if neighbor:
        labelset.update(neighbor_address=neighbor)
    if device:
        labelset.update(device=device)

    # Get a list of all the latest metrics that matches the name and label set
    prom = PrometheusConnect(url=prom_url["url"], disable_ssl=True)
    results = prom.get_current_metric_value(metric_name="bgp_session_state", label_config=labelset)
    if not results:
        typer.echo(message="No results returned :(")
        raise typer.Exit(1)

    # Print out the results
    for metric in results:
        _device = metric["metric"]["device"]
        _neighbor = metric["metric"]["neighbor_address"]
        state_code = int(metric["value"][-1])
        typer.echo(message=f"BGP State for device: {_device} - neighbor {_neighbor} => {BGP_STATES[state_code]}")

Try it out!

python sauron.py --prometheus-host http://localhost:9091 get-bgp-state --device netpanda-jcy-rtr-02