A damn simple DynDNS for Mail-in-a-Box.
Since I didn't want to put my Mail-in-a-Box administrator password across a few boxes that require DynDNS, I had my dog to write this damn simple DynDNS proxy, with no defensive code whatsoever, using Flask and HAproxy.
The DynDNS service will receive requests from any box to update a DNS record given in the URL with the client public IP address. Clients can do this using curl (in your crontab for example):
*/15 * * * * curl -X POST -n https://casi.cauterized.net:5443/update/cauterized.net/home
while storing credentials on a .netrc file:
machine your-miab-dyndns-server
login your-user-for-this-host
password your-password
You can create different authentication credentials for different DNS records in config.py:
URL = 'https://box.domain.tld/admin/'
USER = ''
PASSWD = ';
AUTH = { 'test.domain.tld': {'username':'admin', 'password':'secret'}}
As you might guess, the URL, USER and PASSWD are your Mail-in-a-Box endpoint and administrator credentials.
To run the service, you just need Docker installed:
docker build -t miab-dyndns:latest .
docker run -d --restart always -v $(pwd)/config.py:/app/config.py:ro --name miab-dyndns miab-dyndns
docker run -d --restart always -p 5443:5443 -v $(pwd)/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro -v /home/user-data/ssl/combined.pem:/combined.pem:ro --link miab-dyndns:dyndns --name haproxy haproxy:1.8