tools/bin/update_dns.py

153 lines
3.8 KiB
Python

# Copyright Istio Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import print_function
from google.cloud import dns
import os
import sys
import argparse
import ipaddress
try:
unicode # Python 2
except NameError:
unicode = str # Python 3
class DNSException(Exception):
pass
def find_rs(rs, record_type, name=None):
for r in rs:
if r.record_type != record_type:
continue
if name is None or r.name == name:
return r
return None
def remove_rec(changes, rec):
if rec is not None:
changes.delete_record_set(rec)
# creates
# A record to ingress-${domain}. --> IP
# CNAME *.domain --> ingess-${domain}
# PTR record from IP.in-addr.arpa. --> ingress-${domain}
def register_addr(zone, ip, domain):
if not domain.endswith("."):
domain += "."
rs = list(zone.list_resource_record_sets())
# get the domain managed by this zone
soa_rec = find_rs(rs, "SOA")
if soa_rec is None:
raise DNSException("Could not get SOA record for zone " + zone.name)
zone_domain = soa_rec.name
if not domain.endswith(zone_domain):
raise DNSException(domain + " must be a subdomain of " + zone_domain)
ingress = "ingress-" + domain
cname = "*." + domain
ptr = ".".join(reversed(ip.split('.'))) + ".{}".format(zone_domain)
ingress_rec = find_rs(rs, "A", ingress)
cname_rec = find_rs(rs, "CNAME", cname)
ptr_rec = find_rs(rs, "TXT", ptr)
changes = zone.changes()
remove_rec(changes, ingress_rec)
remove_rec(changes, cname_rec)
remove_rec(changes, ptr_rec)
changes.add_record_set(zone.resource_record_set(ingress, 'A', 300, [ip]))
changes.add_record_set(zone.resource_record_set(
cname, 'CNAME', 300, [ingress]))
changes.add_record_set(
zone.resource_record_set(ptr, 'TXT', 300, [ingress]))
str_changes = changes._build_resource()
try:
changes.create()
except Exception as ex:
print(ex)
print(str_changes)
def get_zone(zone_name, project_id=None):
project_id = project_id or os.environ['PROJECT_ID']
client = dns.Client(project=project_id)
zone = client.zone(zone_name)
if not zone.exists():
raise DNSException(zone_name + " does not exist")
return zone
def main(args):
if args.project_id is None:
args.project_id = os.environ['PROJECT_ID']
zone = get_zone(args.zone_name, args.project_id)
try:
register_addr(zone, args.ingress_ip, args.subdomain)
except DNSException as ex:
print(ex)
return -1
return 0
def validate_ip(addr):
# throws exception for invalid ip addresses
ip = ipaddress.ip_address(unicode(addr))
return addr
def get_parser():
parser = argparse.ArgumentParser(
description="Register dns in a standard way")
parser.add_argument(
"zone_name", help="Cloud dns zone name, example:qual-stio-org")
parser.add_argument("subdomain", help="subdomain to associate with the ip")
parser.add_argument("ingress_ip", type=validate_ip)
parser.add_argument("--project-id")
return parser
if __name__ == "__main__":
parser = get_parser()
args = parser.parse_args()
sys.exit(main(args))
# example:
# python ./update_dns.py qual-stio-org cls1302.v13.qualistio.org
# 35.202.78.224