Updates your domain via hetzner dns api; like dyndns but without any limitations

update_hetzner_home_dns.rb

require 'json'
require 'httparty'

class HetznerDNS
  include HTTParty
  base_uri 'https://dns.hetzner.com'

  def initialize
    @options = {
      headers: {
        'Auth-API-Token' => ENV['HETZNER_DNS']
      }
    }
  end

  def zones
    self.class.get('/api/v1/zones', @options)
  end

  def zone_by_name(name)
    zones['zones'].filter { |r| r['name'] == name }.first
  end

  def records_by_zone_id(zone_id)
    self.class.get('/api/v1/records', @options.merge({ zone_id: zone_id }))
  end

  def create_record(zone_id:, name:, type:, value:, ttl: nil)
    body = {
      name: name,
      type: type,
      value: value,
      ttl: ttl,
      zone_id: zone_id
    }
    self.class.post('/api/v1/records', @options.merge({ body: body.to_json }))
  end

  def update_record(record_id:, zone_id:, name:, type:, value:, ttl: nil)
    body = {
      name: name,
      type: type,
      value: value,
      ttl: ttl,
      zone_id: zone_id
    }
    self.class.put("/api/v1/records/#{record_id}", @options.merge({ body: body.to_json }))
  end
end

current_ip = HTTParty.get('https://api.ipify.org?format=json')['ip']
subdomain = 'myhome'

client = HetznerDNS.new
zone_id = client.zone_by_name('mydomain.com')['id']
record = client.records_by_zone_id(zone_id)['records'].filter { |r| r['name'] == subdomain && r['type'] == 'A' }.first

if record
  puts "Updating dns record with ip #{current_ip}"
  pp client.update_record(
      record_id: record['id'],
      zone_id: zone_id,
      name: subdomain,
      type: 'A',
      value: current_ip
  )
else
  puts "Creating dns record with ip #{current_ip}"
  pp client.create_record(zone_id: zone_id, name: subdomain, type: 'A', value: current_ip)
end