Digital Ocean Dynamic DNS Updater

Tool to implement dynamic DNS using Digital Ocean's DNS API.

Prerequisites

• You must have Go programming installed to build the software locally
• You must have Docker installed to build a Docker image of the software
• You must have an account at Digital Ocean and a domain setup there. The domain must contain the DNS (A) record you want this tool to update.

Build

To download the repository and build the project using locally installed Go tools:

git clone <repo-url>
cd go-do-dyndns
go mod download
CGO_ENABLED=0 go build -ldflags="-w -s" -o build/do-dyndns

Note: Adjust the <repo-url> to where you fetched this repository from. It is published to multiple code hosting services.

Build Docker image

To download the repository and build a Docker image:

git clone <repo-url>
cd go-dyn-dns
docker build -t do-dyndns .

Note: Adjust the <repo-url> to where you fetched this repository from. It is published to multiple code hosting services.

Install

sudo cp build/do-dyndns /usr/local/bin

Configure

This tool is configured using environment variables.

Name	Required	Description
DO_DYN_EXT_IP_URL	Yes	A URL to use for checking the external IP-address. For example: https://ipinfo.io.
DO_DYN_DO_DOMAIN	Yes	The domain in Digital Ocean DNS to update the record for. Must exist before running this tool.
DO_DYN_RECORD_NAME	Yes	The DNS record in the Digital Ocean DNS domain to update. Must be an exiting A DNS record before running this tool.
DO_DYN_API_TOKEN	Yes	An API token for the Digital Ocean API to use for updating the DNS record.
DO_DYN_IP_REGEX	No	A regular expression for finding the IP-address in the data from DO_DYN_EXT_IP_URL. Default is \\b(\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})\\b.
DO_DYN_DNS_TTL	No	Set the TTL (time to live) for the DNS record to update. Default is 60.
DO_DYN_DRY_RUN	No	Set to 1 to enable dry-run mode. In this mode the DNS record will not be updated. Tool will output what it would do. Default is 0.

Run

DO_DYN_EXT_IP_URL=https://ipinfo.io DO_DYN_API_TOKEN=__insert_digitalocean_api_token_here__ DO_DYN_DO_DOMAIN=example.com DO_DYN_RECORD_NAME=dynamic do-dyndns

Run with Docker

docker run --rm --name do-dyndns --env DO_DYN_EXT_IP_URL=https://ipinfo.io --env DO_DYN_API_TOKEN=__insert_digitalocean_api_token_here__ --env DO_DYN_DO_DOMAIN=example.com --env DO_DYN_RECORD_NAME=dynamic do-dyndns

Run as systemd service

Install the systemd unit files:

sudo cp systemd/do-dyndns.{timer,service} /etc/systemd/system/

Configure the service by editing the /etc/systemd/system/do-dyndns.service file to set the environment variables:

sudo nano /etc/systemd/system/do-dyndns.service

After editing the file you must reload the systemd daemon with:

sudo systemctl daemon-reload

Finally enable the systemd units and start the timer unit:

sudo systemctl enable do-dyndns.service
sudo systemctl enable do-dyndns.timer
sudo systemctl start do-dyndns.timer

You can check the service's logs with:

sudo journalctl -u do-dyndns.service

License

This software is licensed under the MIT License - see the LICENSE file for details.