# dyndnsd.rb [![Build Status](https://travis-ci.org/cmur2/dyndnsd.png)](https://travis-ci.org/cmur2/dyndnsd) A small, lightweight and extensible DynDNS server written with Ruby and Rack. ## Description dyndnsd.rb is aimed to implement a small [DynDNS-compliant](http://dyn.com/support/developers/api/) server in Ruby. It has an integrated user and hostname database in it's configuration file that is used for authentication and authorization. Besides talking the DynDNS protocol it is able to invoke an so-called *updater*, a small Ruby module that takes care of supplying the current host => ip mapping to a DNS server. The is currently one updater shipped with dyndnsd.rb `command_with_bind_zone` that writes out a zone file in BIND syntax onto the current system and invokes a user-supplied command afterwards that is assumed to trigger the DNS server (not necessarily BIND since it's zone files are read by other DNS servers too) to reload it's zone configuration. ## General Usage Install the gem: gem install dyndnsd (Optionally install the `json` gem too if you're on Ruby 1.8.) Create a configuration file in YAML format somewhere: ```yaml # listen address and port host: "0.0.0.0" port: "80" # logfile is optional, logs to STDOUT else logfile: "dyndnsd.log" # interal database file db: "db.json" # all hostnames are required to be cool-name.example.org domain: "example.org" # configure the updater, here we use command_with_bind_zone, params are updater-specific updater: name: "command_with_bind_zone" params: zone_file: "dyn.zone" command: "echo 'Hello'" ttl: "5m" dns: "dns.example.org." email_addr: "admin.example.org." # user database with hostnames a user is allowed to update users: # 'foo' is username, 'secret' the password foo: password: "secret" hosts: - foo.example.org - bar.example.org test: password: "ihavenohosts" ``` Run dyndnsd.rb by: dyndnsd /path/to/config.yaml ## Using dyndnsd.rb with [NSD](https://www.nlnetlabs.nl/nsd/) NSD is a nice opensource, authoritative-only, low-memory DNS server that reads BIND-style zone files (and converts them into it's own database) and has a simple config file. A feature NSD is lacking is the [Dynamic DNS update](https://tools.ietf.org/html/rfc2136) functionality BIND offers but one can fake it using the following dyndnsd.rb config: ```yaml host: "0.0.0.0" port: "8245" # the DynDNS.com alternative HTTP port db: "/opt/dyndnsd/db.json" domain: "dyn.example.org" updater: name: "command_with_bind_zone" params: # make sure to register zone file in your nsd.conf zone_file: "/etc/nsd3/dyn.example.org.zone" # fake DNS update (discards NSD stats) command: "nsdc rebuild; nsdc reload" ttl: "5m" dns: "dns.example.org." email_addr: "admin.example.org." # specify additional raw BIND-style zone content # here: an A record for dyn.example.org itself additional_zone_content: "@ IN A 1.2.3.4" users: foo: password: "secret" hosts: - foo.example.org ``` Start dyndnsd.rb before NSD to make sure the zone file exists else NSD complains. ## Using dyndnsd.rb with X Please provide ideas if you are using dyndnsd.rb with other DNS servers :) ## Advanced topics ### Update URL The update URL you want to tell your clients (humans or scripts ^^) consists of the following http[s]://[USER]:[PASSWORD]@[DOMAIN]:[PORT]/nic/update?hostname=[HOSTNAMES]&myip=[MYIP] where: * the protocol depends on your (webserver/proxy) settings * USER and PASSWORD are needed for HTTP Basic Auth and valid combinations are defined in your config.yaml * DOMAIN should match what you defined in your config.yaml as domain but may be anything else when using a webserver as proxy * PORT depends on your (webserver/proxy) settings * HOSTNAMES is a required list of comma separated FQDNs (they all have to end with your config.yaml domain) the user wants to update * MYIP is optional and the HTTP client's address will be used if missing ### SSL, multiple listen ports Use a webserver as a proxy to handle SSL and/or multiple listen addresses and ports. DynDNS.com provides HTTP on port 80 and 8245 and HTTPS on port 443. ### Init scripts The [Debian 6 init.d script](init.d/debian-6-dyndnsd) assumes that dyndnsd.rb is installed into the system ruby (no RVM support) and the config.yaml is at /opt/dyndnsd/config.yaml. ## License dyndnsd.rb is licensed under the Apache License, Version 2.0. See LICENSE for more information.