deno-no-ipv4-here

Inspired by ungleich

A simple microservice that responds the following text to all requests

Sorry, (this part of) domain $domain is not reachable by IPv4. Please upgrade to IPv6 and try to reach $domain again.

Written for Deno.

Configuration

The application uses the following environment variables:

• SERVICE_DOMAIN: The domain where this service is hosted (default: "localhost")
  • Example: SERVICE_DOMAIN=my-ipv6-service.example.com

When making requests to this service, the domain you provide in the back_to parameter will be compared against this value to determine if it should be treated as an external domain.

Running with Deno

1. Install Deno: https://deno.land/manual/getting_started/installation
2. Clone this repository:

   git clone https://git.kyun.li/gunter/ungleich-no-ipv4-here
   cd ungleich-no-ipv4-here
   

3. Start the service:

   deno run --allow-net --allow-read app.ts
   

4. Set the SERVICE_DOMAIN environment variable for your domain:

   SERVICE_DOMAIN=your-domain.example.com deno run --allow-net --allow-read app.ts
   

Running with Docker

1. Build the Docker image:

   docker build -t deno-no-ipv4-here .
   

2. Run the container with your domain configuration:

   docker run -e SERVICE_DOMAIN=your-domain.example.com -p 8080:8080 deno-no-ipv4-here
   

Example Caddy Configuration

Here's a Caddyfile configuration that redirects all non-configured domains to this service:

# Caddyfile
(your_domain) {
    # Your existing configuration for your domain
    reverse_proxy localhost:8080
}

# Catch-all for all other domains
:80, :443 {
    # Redirect to the no-ipv4-here service
    redir https://no-ipv4-here.your-domain.example.com?back_to={host} permanent
}

This configuration:

1. Handles requests for your configured domain normally
2. Redirects all other domains to the no-ipv4-here service
3. Passes the original host as the back_to parameter
4. Uses a permanent redirect (HTTP 301)

Replace no-ipv4-here.your-domain.example.com with the domain where you're running this service.