check_zone.py

#!/usr/bin/env python

import sys
import dns.query
import dns.zone
import dns.name

from dns.exception import DNSException
from dns.rdatatype import SOA

config = {
    'masters': {
        'provider1': '10.10.10.10',
        'provider2': '20.20.20.20'
    },
    'domains': [
        'domain.com',
        'domain.net'
    ]
}

# Zone Transfer
def get_zone(domain, master):
    try:
        zone = dns.zone.from_xfr(dns.query.xfr(master, domain, relativize=False), relativize=False)
    except DNSException as e:
        return None, e

    return zone, None

# Compare a zone against another, return data
def compare_zones(z1, z2):
    data = {
        'totals': [
            get_zone_total(z1),
            get_zone_total(z2)
        ],
        'missing': {},
        'matches': [],
        'mismatches': {}
    }

    # Loop through all the name to rdataset pairs
    for (name, z1_rdataset) in z1.iterate_rdatasets():

        # Skip SOA records (different between providers)
        if z1_rdataset.rdtype == SOA:
            continue

        # Find same record in second zone
        try:
            z2_node = z2.find_node(name)
            z2_rdataset = z2_node.find_rdataset(z1_rdataset.rdclass, z1_rdataset.rdtype)
        except KeyError:
            data['missing'][name] = z1_rdataset
            continue

        # Compare rdatasets
        if z1_rdataset == z2_rdataset:
            if z1_rdataset.ttl == z2_rdataset.ttl:
                data['matches'].append(name)
            else:
                data['mismatches'][name] = [z1_rdataset, z2_rdataset]
        else:
            data['mismatches'][name] = [z1_rdataset, z2_rdataset]

    return data

# Get Total Number of Records
def get_zone_total(zone):
    return sum([len(val) for val in zone.values()]) - 1

if __name__ == '__main__':
    error = False
    for domain in config['domains']:
        print '----------- {} -----------'.format(domain)

        # Perform zone transfer against Provider1
        p1, err = get_zone(domain=domain, master=config['masters']['provider1'])
        if err is not None:
            print 'ERROR: Unable to perform zone transfer against Provider1 for {} ({})'.format(domain, err)
            error = True
            continue

        # Perform zone transfer against Provider2
        p2, err = get_zone(domain=domain, master=config['masters']['provider2'])
        if err is not None:
            print 'ERROR: Unable to perform zone transfer against Provider1 for {} ({})'.format(domain, err)
            error = True
            continue

        # Compare zones to each other
        results = compare_zones(p1, p2)

        p1_total = results['totals'][0]
        p2_total = results['totals'][1]

        # Provider1 total is more than Provider2
        if p1_total > p2_total:
            # Provider2 is missing records
            print 'ERROR: Records missing from Provider2'
            for name, rdataset in results['missing'].iteritems():
                print '{} {}'.format(name, rdataset)
            error = True

        # Provider1 total is less than Provider2
        elif p1_total < p2_total:

            # Compare zones, switching order
            results = compare_zones(p2, p1)

            p2_total = results['totals'][0]
            p1_total = results['totals'][1]

            # Provider2 total is more, Provider1 is missing records
            print 'ERROR: Records missing from Provider1'
            for name, rdataset in results['missing'].iteritems():
                print '{} {}'.format(name, rdataset)
            error = True

        # Provider1 and Provider2 totals are the same
        else:
            # Totals are the same, but records are mismatched
            if len(results['mismatches']) != 0:
                print 'ERROR: Records out of sync'
                for name, rdataset_list in results['mismatches'].iteritems():
                    print "Provider1:\t {} {}".format(name, rdataset_list[0])
                    print "Provider2:\t {} {}".format(name, rdataset_list[1])
                    print
                error = True

            # Totals match, but a record is missing
            elif len(results['matches']) != p1_total:
                print 'ERROR: Records missing from Provider2'
                for name, rdataset in results['missing'].iteritems():
                    print '{} {}'.format(name, rdataset)
                error = True

        # Print report
        print "\nResults"
        print "Provider1 Total:\t", p1_total
        print "Provider2 Total:\t", p2_total
        print "Missing:\t", len(results['missing'])
        print "Matches:\t", len(results['matches'])
        print "Mis-matches:\t", len(results['mismatches'])
        print

    # If any error raised, exit
    if error:
        sys.exit(1)