4 Update DNS records by simply SSH'ing into a server.
6 The idea is to create a separate "dyndns" user on the DNS server.
7 It gets the ``ssh-dyndns`` script as login shell, so that no other programs
9 SSH provides secure, password-less key-based authentication.
11 Upon login, the remote IP is used to create/update a tinydns file with the
12 DNS record for a hostname given by the SSH client.
14 tinydns is part of the dbjdns/dbndns package.
21 1. Clone ssh-dyndns into a sensible location, e.g. ``/usr/local/src/ssh-dyndns``::
23 $ cd /usr/local/src/ && git clone git://git.cweiske.de/ssh-dyndns.git
25 2. Create a user with ``ssh-dyndns`` as login shell::
27 $ useradd -g nogroup -m -N -s /usr/local/src/ssh-dyndns dyndns
29 3. Setup password-less ssh keys for the dyndns user::
31 $ su - dyndns -s /bin/bash
33 $ cat /path/to/key.pub >> ~/.ssh/authorized_keys
35 4. Prevent showing login messages::
37 $ su - dyndns -s /bin/bash
40 Alternatively, you may commend out the "motd" lines in ``/etc/pam.d/sshd``
41 5. Configure ssh-dyndns as root::
43 $ cp /usr/local/src/ssh-dyndns/ssh-dyndns.sh.config-dist /etc/ssh-dyndns.sh
44 $ nano /etc/ssh-dyndns.sh
49 The configuration file template ``ssh-dyndns.sh.config-dist`` may be copied
50 to either ``/etc/ssh-dyndns.sh`` or ``~/.config/ssh-dyndns.sh``.
52 The system-wide config file is loaded first, the user-specific one after that.
54 The configuration file may define the following variables:
57 Path to the tinydns zone files, e.g. ``/etc/tinydns/root/``
59 File name template. ``%DOMAIN%`` will be replaced with the actual
62 Default: ``data-dyndns-%DOMAIN%``
64 DNS entry TTL (time to live) in seconds
72 Simply ssh into the server and pass the hostname as parameter::
74 $ ssh dyndns@example.org home.example.org
76 This will start the ``ssh-dyndns`` script on the remote server, generate
77 the tinydns zone file and run ``make`` in the ``data_dir`` directory to
78 compile the ``data.cdb`` file.
79 tinydns will automatically pick up the change.
85 - IPv6 is not supported yet
91 ssh-dyndns is licensed under the `AGPL v3`__ or later.
93 __ http://www.gnu.org/licenses/agpl.html
99 Written by Christian Weiske, cweiske@cweiske.de