Simple domain list synchronisation tool
=======================================

This tool is designed to work with the AlternC control panel (http://alternc.org)
on Debian, although with the right amount of configuration, it can be made to
work with any platform.

Design principle
================

The master server (or some other server talking to the master) makes the list
of domains to be mirrored on a webpage somewhere. This package will fetch this
list, compare it to its local cache, and configure bind to be a slave for the
new domains detected.

The list is fetched with "wget" by default. The script supports SSL and HTTP
Authentification. It is designed to run through a cron job.

Installation
============

Under debian, just `apt-get install alternc-slavedns`.

Under other platforms, or for porters (this example assumes a FreeBSD install):

 1. Install the script in your `$PATH` (e.g. `/usr/local/sbin/alternc-slavedns`)
 2. Install the configuration file in `/etc/alternc/slavedns/default.conf`
 3. Setup a cronjob like this:

        10 * * * * root /usr/local/sbin/alternc-slavedns > /dev/null

Configuration
=============

Configuration is driver by the `slavedns.conf` (for default values) and scripts
created in the `/etc/slavedns` directory (for each sync'd domain).

Creating a new site
-------------------

In short:

    cd /etc/alternc/slavedns
    cp -p defaults.conf site.conf
    vi site.conf
    alternc-slavedns # optional, should run in the next cron

The settings in `defaults.conf` are self explanatory.

Configuring file locations and programs
---------------------------------------

The `defaults.conf` file can override quite a few locations and programs for
different environments. For example, under FreeBSD, you will probably want:

    CACHEDIR=/var/spool/slavedns
    BINDDIR=/etc/namedb/slavedns
    BINDINCLUDE=/etc/namedb/slavedns.conf

and many sites (including FreeBSD), will require:

    NAMED="ndc restart"

Some servers might also require:

    WGETFLAGS="--no-check-certificate"

if they don't have a "real" SSL certificate.

Surviving disasters
-------------------

It is sometimes possible that this setup degenerates to the point it can't reach
the master server, for example if the server is reached through DNS.

For this reason, it might be advisable to hardcode those domain names in `/etc/hosts`
so that if this nameserver looses its zonefiles, it can at least fetch them again
from the upstream.

Source
------

Copied from a history-less SVN checkout after the original depot was lost. See
also https://gitlab.com/anarcat/alternc-slavedns/