Fetch It service

Using this, people can update Dynamic DNS names (Now, only Google DNS service) that are censored in Iran.

Status

Note: To use this service, As well as a VPS, you need to have a domain with Google Domain service You have to set the DNS servers to use Google DNS service (default DNS server settings).

How to build

This service is a Go pure code, so you just need to go to compile it.

1. Install Go 1.21.1+
2. run go get -v -u to install and update dependencies
3. run GOOS=linux GOARCH=amd64 go build -v -ldflags "-w -s" -o MY-SERVICE-NAME.app to compile it for Linux on amd64 platforms, check Go Documentation for more information to build for other platforms.
4. (optional) use UPX to reduce the size by running upx MY-SERVICE-NAME.app

Also, You can use the deploy.sh bash script to compile and deploy the service on your VPS using SSH and SCP tools.

How to Use

Step-by-step guide to deploy the service:

• on Google Domain:
  • Go to domains.Google.com and select your domain
  • Add a subdomain with DDNS record by following these steps: DNS → Advanced Settings → Manage Dynamic DNS.
  • Save the subdomain name
  • Copy the credentials by following these steps: DNS → Advanced Settings → Your domain has Dynamic DNS set up → View Credentials.
• On the VPS:
  • Update the credential data file. Use cred-sample.jsonc as template.
    • file format is jsonc. Format is so like the json but can comment lines using // at the beginning of line.
    • every domain needs one entry in the config file with a unique name. that will be used as username for auth request.
    • the password is the password you need to use it in your auth request.
    • the host is the subdomain name.
    • the dd-user and dd-pass are the Google DNS DDNS service credential.
  • Then upload the credential file to the VPS in /etc/websites/YOUR_DOMAIN_NAME folder
  • Update the configuration of service using config.ini as you need
  • Upload it to /etc/websites/YOUR_DOMAIN_NAME/config.ini
  • start the app to serve your requests (or set up a service using systemd or a daemon, see sample-service.service for a sample systemd service implementation)
• on the client:
  • you need to use curl, wget or any other get request to fetch the VPS service.
    • to set the IP address manually, add ?myip=192.168.1.1
    • if you do not set the IP address manually in the request, the service detects your public IP address.
    • the service checks the current IP address before requesting Google DDNS to update the IP of record.
      • to force update,
        • for all accounts: add the force=yes to the service config file
        • for only one of requests: add the force=yes to the request URL parameters (not implemented yet)
    • Using the TLS is strongly suggested for your safety

TODO

This functionality will be added in the future:

1. Don't try to update if the IP is already correct.
2. Support listen to secure port
3. Add test codes
4. Support generate and use certificate using Let's Encrypt services
5. add support for:
   • no-ip.com
   • dyndns.org
6. write a man file
7. add support force=yes parameter in the request url
8. render /about page from MarkDown to HTML

Author

• Sadeq N. Yazdi code[@]sadeq[dot]uk>

Copyright

see GPLv3 https://www.gnu.org/licenses/gpl-3.0.txt