axfr2route53

#!/usr/bin/env python3

# Author: Michael Ludvig - https://aws.nz/aws-utils/axfr2route53
# License: BSD

# Convert DNS zone from Bind's "dig axfr" format to AWS Route53 JSON input
# Usage:
#  1) dig axfr example.com. @ns.example.com. | axfr2route53 > example-com.json
#  2) aws route53 change-resource-record-sets --hosted-zone-id ZABCDEF123456 --change-batch file://example-com.json
#  3) Update list of nameservers to AWS ones through example.com's registrar

import re
import sys
import json

if len(sys.argv) > 1:
    inp = open(sys.argv[1], 'r')
else:
    inp = sys.stdin

changes = {}
zone_name = ""

while True:
    line = inp.readline()
    if not line:
        break
    line = line.strip()
    rr = re.match('^(?P<name>\S+)\s+(?P<ttl>\d+)\s+(?P<class>\w+)\s+(?P<type>\w+)\s+(?P<data>.*)$', line)
    if not rr:
        continue

    if rr.group('class') != "IN":
        sys.stderr.write("Unknown class, only supporting IN: %s" % line)
        continue
    if rr.group('type') == "SOA":
        # Ignore SOA records
        zone_name = rr.group('name')
        continue
    if rr.group('type') == "NS" and rr.group('name') == zone_name:
        # Ignore zone NS records
        continue

    # Merge records of the same type, e.g. all A records for the same name
    change_id = "%(name)s/%(type)s" % rr.groupdict()
    if change_id in changes:
        changes[change_id]["ResourceRecordSet"]["ResourceRecords"].append({
            "Value": rr.group('data')
        })
    else:
        changes[change_id] = {
            "Action" : "CREATE",
            "ResourceRecordSet" : {
                "Name" : rr.group('name'),
                "Type" : rr.group('type'),
                "TTL"  : int(rr.group('ttl')),
                "ResourceRecords" : [{
                    "Value" : rr.group('data')
                }]
            }
        }

if changes:
    change_batch = {
        "Changes": list(changes.values())
    }
    print(json.dumps(change_batch, indent=2))