How to list Google Cloud NAT ips for a project

gcp-list-nat-ips.py

#!/usr/bin/env python3
# encoding: utf-8

"""
Lists all the GCP CloudNat IP addresses in a list of projects

Usage:

    ./gcp-list-nat-ips.py --project <gcp-project-name>
"""

import click
from typing import List

from google.cloud.compute_v1.services.routers import RoutersClient
from google.cloud.compute_v1.services.addresses import AddressesClient
from google.cloud.compute_v1.types import compute, Address, Router, RouterNat
# from google.oauth2 import service_account


def get_addresses(project: str) -> list:
    client = AddressesClient()
    request = compute.AggregatedListAddressesRequest(project=project)
    response = client.aggregated_list(request, timeout=5.0)
    results_list = list()

    for zone, addresses_list in response:
        if len(addresses_list.addresses) > 0:
            for address in addresses_list.addresses:
                results_list.append((address.self_link, address,))

    return results_list


def get_routers(project: str) -> list:
    client = RoutersClient()
    request = compute.AggregatedListRoutersRequest(project=project)
    response = client.aggregated_list(request, timeout=5.0)
    results_list = list()

    for zone, routers_list in response:
        if len(routers_list.routers) > 0:
            for router in routers_list.routers:
                results_list.append((zone, router.name, router,))

    return results_list


def get_router_nat_ips(router: Router) -> list:
    nats: List[RouterNat] = router.nats
    ips = list()

    for nat in nats:
        ips.extend(nat.nat_ips)

    return ips


def to_dict(l: list) -> dict:
    result_dict = dict()
    for k, v in l:
        if k in result_dict:
            raise KeyError(f"Would overwrite existing value for {k}")
        result_dict[k] = v

    return result_dict


@click.command()
@click.option("--project", "-p", required=True, multiple=True)
def main(**options):

    for project in options["project"]:
        project_routers = get_routers(project)

        if not project_routers:
            continue

        project_addresses = to_dict(get_addresses(project))

        for zone, name, router in project_routers:

            nat_ips = get_router_nat_ips(router)
            for ip in nat_ips:

                resolved = project_addresses[ip]
                print("\t".join((
                    project,
                    zone,
                    router.name,
                    router.description,
                    resolved.address,
                    resolved.description,
                )))


if __name__ == "__main__":
    main()