Read yaml in python with PyYAML, install requirements with pip, hosts.yml contains some ip addresses of dns servers, perform a nslookup on the ip

host_inventory.py

#!/usr/bin/python
import yaml


def read_hosts_file(file):
    try:
        stream = open(file, 'r')
        hosts = yaml.load(stream)
        return hosts
    except IOError:
        print("Can't read from ", file)

hosts.yml

---
- 52.85.89.116
- 185.70.40.182
- 172.217.7.195

network_agent.py

#!/usr/bin/python

from dns import reversename, resolver


def ip_lookup(ip):
    rev_name = reversename.from_address(ip)
    reversed_dns = str(resolver.query(rev_name, "PTR")[0])
    return reversed_dns

requirements.txt

pyyaml
dnspython

test_read_hosts_file.py

from unittest import TestCase
import host_inventory
import network_agent
import os

class TestRead_hosts_file(TestCase):
    def test_read_hosts_file(self):
        file = os.path.join('C:\\', 'Users', 'cinhtau', 'PycharmProjects', 'network-mapper', 'resources', 'test.yml');
        hosts = host_inventory.read_hosts_file(file)
        for host in hosts:
            print(host, '=', network_agent.ip_lookup(host))
        print("\n")