Now the returncode of nsupdate is evaluated.

[toast/tdyndns.git] / bin / nsupdate_dyndns

diff --git a/bin/nsupdate_dyndns b/bin/nsupdate_dyndns
index dd9d5f0e31fa155250a9a015fa783b6a6457b3ad..237c7882aa5bcf9000631619e05d8b873b53a0de 100755 (executable)
--- a/bin/nsupdate_dyndns
+++ b/bin/nsupdate_dyndns
@@ -1,9 +1,85 @@
-#!/bin/bash
+#!/usr/bin/python
+import sys
+import re
+import argparse
+from subprocess import Popen, PIPE
+import ipaddr
 
-hostname=$1
-myip=$2
-type=$3 # A or AAAA
-ttl=600
-domain=dyn.colgarra.priv.at
 
-echo -e "update delete $hostname.$domain $type\nupdate add $hostname.$domain $ttl IN $type $myip\n" | nsupdate -l
+class NsupdateError(Exception):
+       def __init__(self, returncode):
+               self.returncode = returncode
+
+
+def ipfamily_by_ip(ip):
+       if isinstance(ip, ipaddr.IPv4Address):
+               return 'A'
+       elif isinstance(ip, ipaddr.IPv6Address):
+               return 'AAAA'
+       assert False
+
+
+def nsupdate_add(fqdn, ttl, ip):
+       """
+       :param fqdn: Fully qualified domain name
+       :param ip_family: A or AAAA
+       :raises an NsupdateError in case of errors."""
+       command = "update add {fqdn} {ttl} IN {ip_family} {ip}\n\n".format(fqdn=fqdn, ttl=ttl, ip_family=ipfamily_by_ip(ip), ip=ip)
+       p = Popen(['nsupdate', '-l'], stdin=PIPE)
+       p.communicate(command)
+       if p.returncode != 0:
+               raise NsupdateError(p.returncode)
+
+
+def nsupdate_delete(fqdn, ip_family):
+       """
+       :param fqdn: Fully qualified domain name
+       :param ip_family: A or AAAA
+       :raises an NsupdateError in case of errors."""
+       command = "update delete {fqdn} {ip_family}\n\n".format(fqdn=fqdn, ip_family=ip_family)
+       p = Popen(['nsupdate', '-l'], stdin=PIPE)
+       p.communicate(command)
+       if p.returncode != 0:
+               raise NsupdateError(p.returncode)
+
+
+def main(args):
+       try:
+               if args.delete:
+                       if args.ip is None:
+                               nsupdate_delete(args.fqdn, 'A')
+                               nsupdate_delete(args.fqdn, 'AAAA')
+                       else:
+                               nsupdate_delete(args.fqdn, ipfamily_by_ip(args.ip))
+               else:
+                       nsupdate_delete(args.fqdn, ipfamily_by_ip(args.ip))
+                       nsupdate_add(args.fqdn, args.ttl, args.ip)
+       except NsupdateError as e:
+               sys.exit(e.returncode)
+
+
+
+if __name__ == '__main__':
+       parser = argparse.ArgumentParser(description='Add or delete a domain name from dyndns (simplifies call to nsupdate).')
+       parser.add_argument('-d', '--delete', action='store_true', help='delete instead of add')
+       parser.add_argument('-i', '--ip', help='IP address (either IPv4 or IPv6)')
+       # parser.add_argument('-t', '--ttl', type=int, default=600, help='TTL (default: 600)')
+       parser.add_argument('fqdn', help='fully qualified domain name to add or delete, e.g. myserver.dyn.example.com')
+       args = parser.parse_args()
+
+       args.ttl = 600 # <---- TODO
+
+       # check ip
+       if not args.delete and not args.ip:
+               parser.error('The IP address is mandatory')
+       if args.ip:
+               try:
+                       args.ip = ipaddr.IPAddress(args.ip) # throws an exception if the IP address is not valid
+               except ValueError:
+                       parser.error('The IP address is not valid')
+
+       # check fqdn
+       if re.match(r'[-0-9a-z]+(\.[-0-9a-z]+)*$', args.fqdn) is None:
+               parser.error('The fqdn has an invalid format.')
+
+       main(args)