gcp-subscription-auto-ip-update

Use a systemd oneshot service triggered at boot that runs an IP check script comparing the current public IP to the last recorded one. On change, call a Cloudflare API script with the new IP passed explicitly as an argument to update the DNS A record.

Run a lightweight Python http.server that maps URL paths to local YAML subscription files and requires a key query parameter, returning 401 without it. Manage it with a systemd unit using Restart=always so it survives crashes and reboots.

The most common cause is calling the update script without passing the new IP as an argument, which makes it fail silently. Also verify the script has execute permission with chmod +x and add curl timeouts since networking may not be fully ready at boot.

Yes, use the GitHub Contents API with a PUT request authenticated by a personal access token that has Contents read and write permission. Classic tokens with repo scope tend to be more reliable than fine-grained tokens for this kind of automation.

Common causes are the token belonging to a different GitHub account, a fine-grained token missing Contents read and write permission, or missing SSO authorization. Test with curl -u username:token against the API user endpoint to isolate authentication from permission issues.