dns_filter.py

import json, sys
import argparse


parser = argparse.ArgumentParser()
parser.add_argument("name")
parser.add_argument("value")
args = parser.parse_args()

dns = json.load(sys.stdin, encoding='utf-8')

for i, record in enumerate(dns["CommonServiceItem"]["Settings"]["DNS"]["ResourceRecordSets"]):
        if record["Name"] == args.name:
                dns["CommonServiceItem"]["Settings"]["DNS"]["ResourceRecordSets"][i]["RData"] = args.value


print(json.dumps(dns, indent=4))