This shell script implements dynamic DNS using the DomRobot XML-RPC API by INWX.
This script can update nameserver entries with your current WAN IPv4 and IPv6 addresses.
It uses the nameserver.updateRecord method of the API.

advantage: You don't need payed dynDNS-accounts for multiple domains.
disadvantage: The minimum TTL is 300 (5 minutes). The dynDNS-Service allowes 60 (1 minute).

There exists the dyndns.updateRecord method in the DomRobot API. Therefore you need a DynDNS-account by INWX. If you need this option, feel free to change the script to your needs.

nsupdate is fully POSIX compliant and should work in every shell.

Nevertheless it has some dependencies to use it:

• xmllint (Look for libxml2-utils (Debian, Ubuntu) or libxml2 (FreeBSD, CentOS)). It's used for Getting the ID and the current IP from the INWX API. This is the recommended way.

• If you dont't have installed xmllint, you need either nslookup or drill to query the nameserver for the current IP. In this case you must define the specific INWX IDs in the config files for your INWX records.

• A hard requirement is curl as it's used to make the API calls.

Note: 2-Factor-Authentification method (2FA) is not supported when using the INWX API.

Simply clone this project or download the master.zip and extract it, e.g., using wget and 7z x master.zip.

Move the included nsupdate directory to /usr/local/etc (see the config section if you want to use another path) and nsupdate.sh anywhere in your $PATH (e.g. /usr/local/bin or ~/bin).

[TODO] TMP DIR [TODO] LOG DIR

[TODO] nsupdate.conf [TODO] DNS record conf [TODO] Backwards compatibility

With crontab -e you can add the following line for running the script every 5 minutes:
*/5 * * * * bash /home/$USER/nsupdate/nsupdate.sh

Beta

• Completly rewritten. nsupdate is now a POSIX compliant /bin/sh script 👍🏻
• If using the xmmlint method, now also the IP for a record is retrieved this way
• WAN IP now is only checked once per session instead of every time a new config is processed.
• The script now automagically determines the best way to get the needed data (xmllint, nslookup, drill) and has some nice output options.
• The code is now structured in functions which makes it more maintainable and modular.
• Backwards compatibility should be given.
• Avoid using awk and get rid of dependency

2021-12-11

• Added the possibility to retrieve the WAN IP by a shell command (e.g. SSHing into your router and get the IP of the WAN interface)

2020-07-03

• Rearranged config.sample
• Updated Readme
• Getting the Domain-Record-ID via XML-RPC API

2020-05-11

• Updated Readme with some hints
• Updated config.sample with a hint for TTL

2020-03-31

• Made time to live configurable

2019-12-20

• Fixed DomRobot XML-RPC API syntax
• Added some more documentation

2015-07-22

• Changed the way how the existence of config files is checked
• Updated the sample config file to reflect new options from the last updates
• The script is reported to work in csh and sh too

2015-06-30

• Fixed the check for config files. Can now handle more than one file
• Changed warning for missing config files

2015-01-12

• Added checks for needed commands
• Added checks for existing config file
• Added requirements to README.md

2014-02-21

• Added support for IPv6
• Added support for config files

2014-01-02

• Changed default IP check site to ip.dblx.io
• Added a switch to use drill instead of nslookup because FreeBSD 10 switched from bind to unbound
• Renamed $HOSTNAME to $DOMAIN to work around potential conflicts with $HOSTNAME that's set by the host itself

2014-01-06

• Config files are sourced relative to the script folder now

2013-07-12

• First commit

nsupdate is distributed under the MIT license, which is similar in effect to the BSD license.

Copyright 2013 Christian Busch (http:https://github.com/chrisb86)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.