a dsl for managing domain names, concrete implementation tied to linode's api

dns.rb

require 'linode'
require 'json'

EMAIL = "matt@flowerpowered.com"
L = Linode.new(api_key:"...")

class Domain
  def initialize(name)
    @hostname = name
    @id = 0
    @a = {}
    @cname = {}
    @txt = []
    @srv = []
    @mx = {}
    r = L.domain.create(domain: @hostname, type:'master', soa_email: EMAIL)
    @id = r.domainid
  end
  
  def ip(val=nil)
    if val
      @ip = val
    else
      @ip
    end
  end
  
  def a(hosts, value=nil)
    hosts = [hosts].flatten
    hosts.each do |host|
      @a[host] = value || ip
    end
  end
  
  def google
    {'aspmx' => 1, 'alt1.aspmx' => 5, 'alt2.aspmx' => 5}.each do |h,v|
      mx("#{h}.l.google.com", v)
    end
    {'aspmx2' => 10, 'aspmx3' => 10, 'aspmx4' => 10, 'aspmx5' => 10}.each do |h,v|
      mx("#{h}.googlemail.com", v)
    end
    {'' => 5, '1' => 20, '2' => 20, '3' => 20, '4' => 20}.each do |serv, v|
      srv(0, 5269, 'xmpp-sever', 'tcp', "xmpp-server#{serv}.l.google.com", v)
      srv(0, 5269, 'jabber', 'tcp', "xmpp-server#{serv}.l.google.com", v)
      if v.to_i < 3
        srv(0, 5222, 'xmpp-client', 'tcp', "talk#{srv}.l.google.com", v)
      end
    end
    txt("v=spf1 a mx include:aspmx.googlemail.com ~all")
  end
  
  def mx(host, value)
    @mx[host] = value
  end
  
  def srv(weight, port, service, protocol, target, value)
    @srv << {weight:weight, port:port, protocol:protocol, target:target, value:value, name:service}
  end
  
  def txt(data)
    @txt << data
  end
  
  def cname(host, target)
    @cname[host] = target
  end
  
  def to_records
    @a[''] = ip if @a[''].nil? && @cname[''].nil?
    @a['*'] = ip if @a['*'].nil? && @cname['*'].nil?
    records = @a.map {|k,v| {type: "A", name: k, target: v} }
    records += @txt.map {|r| {type: "TXT", name: @hostname, target: r}}
    records += @mx.map {|k,v| {type: "MX", target:k, priority: v} }
    records += @cname.map {|k,v| {type: "CNAME", name:k, target: v} }
    records += @srv.map {|r| {type: "SRV"}.update(r) }
    records.each {|r| r.update(domainid: @id)}
    records
  end
  
end

def domain(name, &block)
  d = Domain.new(name)
  d.instance_exec &block
  d.to_records.each do |r|
    puts "creating: #{r}"
    L.domain.resource.create(r)
  end
end

records.rb

require "dns"

domain("example.com") do
  ip "192.168.1.1"
  a "*"
  a "staging", "192.168.1.2"
  cname "foo", "foobar.com"
  
  mx "mail.example.com", 10
  
  txt "fuck yeah text records!"
end