Automatically keep a DNS record set to your current IP address using dnscontrol.

See development, no package has been published yet.

Run dyndnsctrl in the same directory that you would run dnscontrol.

Clone the repo and install dependencies into a local virtual environment:

python -m venv .venv
source .venv/bin/activate.fish
pip install --upgrade pip
pip install --editable .
dyndnsctrl

Optional environmental variables:

DNSCONFIG_PATH=./dnsconfig.js
SUBDOMAIN=homelab # e.g. homelab.example.com
DOMAIN=example.com
UNATTENDED=1
LOG_LEVEL=info # or debug

These environmental variables make the script flexible and adaptable for different operational environments and use cases, such as automating DNS updates in response to IP address changes for a specific subdomain.

The optional DOMAIN variable will use dnscontrol --domains option to limit the update to a specific domain, which is useful if you have more than one domain. It will reduce the amount of api calls that dnscontrol does.

In order to automate the process of updating DNS records with dnscontrol whenever your public IP changes, you can utilize systemd to schedule and run a Python script periodically. Here’s how to configure systemd with user services and timers to manage this task:

The following steps will guide you through setting up a user service and a timer using systemd. This will ensure that your DNS records are automatically updated on a regular schedule.

Create a systemd service file to define how the script should run. This file will specify the script to execute, the type of service, and its working directory.

1. Create the service file at ~/.config/systemd/user/dyndnsctrl.service with the following content:

   [Unit]
   Description=Run dyndnsctrl
   
   [Service]
   Type=oneshot
   ExecStart=dyndnsctrl
   EnvironmentFile=/path/to/.env
   WorkingDirectory=/home/me/dnscontrol
   
   [Install]
   WantedBy=multi-user.target

   • Type=oneshot indicates that the service runs the script once and then exits.
   • ExecStart should point to the Python executable followed by the path to your script. Modify the path to match where your Python script is located.
   • WorkingDirectory is set to the directory containing your DNS control files.

Create a systemd timer file to schedule when the service runs. This timer will activate the service according to a set interval.

1. Create the timer file at ~/.config/systemd/user/dyndnsctrl.timer with the following content:

   [Unit]
   Description=Check our IP address every 15 minutes
   
   [Timer]
   OnBootSec=15min
   OnUnitActiveSec=15min
   
   [Install]
   WantedBy=timers.target

   • OnBootSec specifies how long after booting the system the timer should first activate.
   • OnUnitActiveSec sets the interval between each activation of the timer.

After creating the service and timer files, you need to tell systemd to start using these new configurations.

1. Reload systemd to recognize new or changed units:

   systemctl --user daemon-reload

2. Enable and start the timer to begin scheduling your script:

   systemctl --user enable --now dyndnsctrl.timer

   • enable configures the timer to start automatically at boot.
   • --now starts the timer immediately without needing to reboot.

With these configurations in place, your Python script will automatically run every 15 minutes, ensuring that any changes to your public IP address are quickly reflected in your DNS settings. This setup is particularly useful for dynamic IP environments, such as home networks or small offices without static IP addresses. Be sure to replace paths and other details with those specific to your environment.