dnsip.io/dnsip.dev - A very simple xip.io clone

dnsip.sh

DIR=`pwd`
read -p 'Acme Account Thumbprint: ' ACME_THUMBPRINT

# Basics
sudo apt update
sudo apt upgrade -y

# Turn off systemd DNS resolver
sudo sed -ri 's/#?DNSStubListener=yes/DNSStubListener=no/g' /etc/systemd/resolved.conf
sudo sh -c 'rm /etc/resolv.conf && ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf'
sudo systemctl restart systemd-resolved

# Install Caddy
sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list
sudo apt update
sudo apt install -y caddy

cat <<CADDY | sudo tee /etc/caddy/Caddyfile
dnsip.io, www.dnsip.io, dnsip.dev, www.dnsip.dev {
	@achallenge {
		path_regexp ch ^/\.well-known/acme-challenge/([-_a-zA-Z0-9]+)$
	}
	respond @achallenge "{re.ch.1}.$ACME_THUMBPRINT"
	redir "https://gist.github.com/michaelkitson/6dea89e80124ab5b315592d9dbebd1dd"
}
CADDY

# Install Ruby DNS server
sudo apt install -y docker.io
cat <<RUBY > dns.rb
#!/usr/bin/env ruby

require "bundler/inline"

gemfile do
  source "https://rubygems.org"
  gem "rubydns", "~> 2.0.2"
end

IN = Resolv::DNS::Resource::IN
Name = Resolv::DNS::Name
a = %w[3.18.94.92 3.134.52.66]
aaaa = %w[2600:1f16:bb1:c300:1b51:ef4f:f14a:9e45 2600:1f16:bb1:c301:549:4e5b:7df6:7d6f]
bare_regex = /\Adnsip\.(io|dev)\z/
www_regex = /\A(www\.)?dnsip\.(io|dev)\z/
ip_regex = /(\d+([-.]\d+){3})\.dnsip\.io\z/
RubyDNS.run_server do
  match(ip_regex, IN::A) do |tx|
    tx.respond!(tx.name.match(ip_regex).captures.first.tr("-", "."))
  end

  match(bare_regex, IN::SOA) do |tx|
    tx.respond!(Name.create("ns1.#{tx.name}"), Name.create("dns.#{tx.name}"), 1, 86400, 7200, 604800, 3600)
  end

  match(bare_regex, IN::NS) do |tx|
    %w[ns1 ns2].each { tx.respond!(Name.create("#{_1}.#{tx.name}")) }
  end

  match(www_regex, IN::A)    { |tx| a.each    { tx.respond!(_1) } }
  match(www_regex, IN::AAAA) { |tx| aaaa.each { tx.respond!(_1) } }
  match(/dnsip\.(io|dev)\z/) { |tx| tx.fail!(:NXDomain) }
end
RUBY

chmod +x dns.rb
sudo docker run --name dns -d --restart=always -p53:53/udp -p53:53/tcp -v "$DIR/dns.rb:/dns.rb" ruby:3.3 /dns.rb

# Wrap up
sudo reboot