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.

In order to run the script you need to have installed the following command line tools:

• curl
• awk
• nslookup or drill

recommendation

• xmllint
  Look for libxml2-utils (Debian, Ubuntu) or
  libxml2 (FreeBSD, CentOS),
  xmlstarlet is also available on many systems and it gets xmllint.
  If xmllint is not on your system you have to set the domain record id in your config files.

Note: 2-Factor-Authentification method (2FA) is not implemented.

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

Place your config files in the nsupdate.d folder. A dist.config.sample file with all possible options is provided. At least one config file needs to exist, ending with .config.
All .config files (one for each dns-record) will be processed by looping them.

For home.example.com you may create:
A-Record Update configuration e.g.
myV4.config

INWX_USER="USERNAME"
INWX_PASS="PASSWORD"
MAIN_DOMAIN="example.de"
DOMAIN="home.example.de"
TYPE="A"
IP_CHECK_SITE="https://api.ipify.org"

AAAA-Record Update configuration e.g.
myV6.config

INWX_USER="USERNAME"
INWX_PASS="PASSWORD"
MAIN_DOMAIN="example.de"
DOMAIN="home.example.de"
TYPE="AAAA"
IP_CHECK_SITE="https://api6.ipify.org"

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

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.