Cloudflare Dynamic DNS Updater

cloudflare_dyndns_update is a simple tool written in Ruby to update Dynamic DNS entries on Cloudflare. Following APIs are used in this tool:

https://developers.cloudflare.com/api/operations/dns-records-for-a-zone-list-dns-records https://developers.cloudflare.com/api/operations/dns-records-for-a-zone-patch-dns-record

Installation

The tool can be run by executing cloudflare_dyndns_update.rb script from a clone of this repository.

Configuration

This tool uses a configuration file, located by default in ~/.cfdyndns.yaml, to get information on hosts to update. An alternate configuration file can be specified with the -f|--config_file option. Configuration is specified in YAML format with a template as follows:

hosts:
- host: hostone.com
  zone_id: <cloudflare hostone zone_id>
- host: hosttwo.com
  zone_id: <cloudflare hosttwo zone_id>
- ...

Zone IDs for this file can be obtained from the Cloudflare dashboard as mentioned in the URL below.

https://developers.cloudflare.com/fundamentals/setup/find-account-and-zone-ids/

Caching

To avoid frequent queries to Cloudflare, tool stores the status of latest update to a cache file, located by default in ~/.cfdyndns.cache. Alternate location may be provided with -c|--cache_file option.

Cloudflare is updated only if public IP of the host has changed. An update can, however, be forced with the -u|--force_update option.

Usage

Following usage help is available with the --help option:

$ cloudflare_dyndns_update.rb --help
Usage: cloudflare_dyndns_update.rb [options]
    -d, --debug                      Enable debug messages
    -u, --force_update               Force DNS update
    -f, --config_file FILE           Location of configuration file
    -c, --cache_file FILE            Location of cache file
    -k, --api_key KEY                Cloudflare API authorization key
    -h, --help                       Display this help

Sample log

I, [2024-02-04T12:04:54.361716 #878203]  INFO -- /home/mahesh/tools/cloudflare_dyndns_update/cloudflare_dyndns_update.rb: Starting...
I, [2024-02-04T12:04:54.538701 #878203]  INFO -- : Public IP: <public IP>
I, [2024-02-04T12:04:54.995094 #878203]  INFO -- : Successfully updated DNS entry type A - <host one> - <public IP>
I, [2024-02-04T12:04:55.725365 #878203]  INFO -- : Successfully updated DNS entry type A - <host two> - <public IP>
I, [2024-02-04T12:04:56.009757 #878203]  INFO -- : Successfully updated DNS entry type A - <host three> - <public IP>
I, [2024-02-04T12:04:56.010129 #878203]  INFO -- : Writing updated cache file
I, [2024-02-04T12:04:56.011406 #878203]  INFO -- /home/mahesh/tools/cloudflare_dyndns_update/cloudflare_dyndns_update.rb: Done.
...
I, [2024-02-04T12:07:24.238077 #879022]  INFO -- /home/mahesh/tools/cloudflare_dyndns_update/cloudflare_dyndns_update.rb: Starting...
I, [2024-02-04T12:07:24.419129 #879022]  INFO -- : Public IP: <same public IP>
I, [2024-02-04T12:07:24.419249 #879022]  INFO -- : Skipping <host one> - Already pointing to <same public IP>
I, [2024-02-04T12:07:24.419295 #879022]  INFO -- : Skipping <host two> - Already pointing to <same public IP>
I, [2024-02-04T12:07:24.419331 #879022]  INFO -- : Skipping <host three> - Already pointing to <same public IP>
I, [2024-02-04T12:07:24.419365 #879022]  INFO -- /home/mahesh/tools/cloudflare_dyndns_update/cloudflare_dyndns_update.rb: Done.

License

This tool is licensed under the MIT License.