radd

Minimal dynamic DNS service

Installation

gem install radd

Configuration

# radd.yml
origin: ddns.example.com
ip: 10.1.2.3
mname: ns.example.com
rname: hostmaster.example.com
ttl: 300
http: 127.0.0.1:3000
dns: 0.0.0.0:53
db: radd.sqlite3

origin

Your domain where subdomains are the dynamic hostnames

ip

The nameserver's public IP

mname

Hostname of the nameserver, must not be a subdomain of origin

rname

Email address of the nameserver contact, default: hostmaster.ORIGIN

ttl

TTL of the dynamic A records, default: 300

http

ÌP:port the HTTP server should listen on, default: 127.0.0.1:3003

dns

IP:port the DNS server should listen on, default: 0.0.0.0:53

db

Path to the zone db, default: radd.sqlite3

Usage

radd COMMAND [--config FILE]

You must specify one of the following commands:

setup        Create the database
add          Add new record
delete       Delete record
list         List available records
start        Run the server

Deployment

Webserver

The HTTP server should be exposed via a reverse proxy like Nginx, which provides SSL encryption.

Nameserver

The DNS ports (53/udp, 53/tcp) can be exposed directly when using systemd to run radd. The provided unit file (radd.service) includes the necessary directives which enable an unprivileged user to access port 53.

DNS configuration

You need to set your dynamic DNS server as the authoritative nameserver for the used (sub)domain:

NS  ddns.example.com   ns.example.com.   86400

Updating a record via HTTP

In order to update a record, an authorized request must be made to the /update endpoint.

The hostname is determined by the HTTP user name. The IP address can be supplied by the ip parameter, otherwise, the remote IP of the request will be used:

# use remote IP
curl --user "hostname:password" https://ddns.example.com/update

# use given IP
curl --user "hostname:password" https://ddns.example.com/update?ip=10.20.30.40