Namecheap Dynamic DNS Updater

Just a simple bash + cURL + dig based updater for the Namecheap Dynamic DNS service.

This client stores the last successful IP address sent to Namecheap in a local file cache. The current public IP is sent to Namecheap only if this IP differs from the cached IP. The cached IP is invalidated using -f flag, or when it differs from the dynamic hostname resolved IP.

Configuration

Provide a configuration via a set of environment variables, or using a configuration file (with the same variables defined).

E.g., if your DDNS domain name is ddns.example.com, the content of the env variables or of the configuration files should be:

NC_DDNS_HOST=myhost
NC_DDNS_DOMAIN=example.com
NC_DDNS_PASSWORD=namecheap-ddns-password

The NC_DDNS_PASSWORD shall be retrieved from the Namecheap web control panel.

Usage

Usage: nc-ddns [-c config-file] [-d] [−n] [-h] [−f]

Options:
 -c :  Configuration file path (default: get config via env variables)
 -d :  print debug info (default: false)
 -f :  Force update (invalidate the cached IP)
 -h :  help
 -n :  Dry-run

Pass the -f flag to force IP to Host update, no matter the cache content.

With cron

This is supposed to be used with something like cron with for periodically refreshing the DNS domain name, e.g. add to crontab -e:

# update DDNS
*/5 * * * *    cd ~/nc-ddns && chronic ./nc-ddns.sh | logger -t nc-ddns

Limitations

• Right now only a single host per machine is supported.
• Cache file path is hard-coded.

Notes