Create resource_record type

Abstract out the nsupdate provider logic and implement a new resource_record
type around it which applies no semantic value to its title.

Also: support SPF and TXT records, include isrequired on required parameters
(though it doesn't seem to work as advertised)

lib/puppet_bind/provider/nsupdate.rb

@@ -0,0 +1,125 @@
+require 'tempfile'
+
+module PuppetBind
+  module Provider
+
+    def self.nsupdate_provider(type)
+    end
+
+    module NsUpdate
+
+      def exists?
+        !(query.empty?)
+      end
+
+      def create
+        update do |file|
+          accio(file)
+        end
+      end
+
+      def destroy
+        update do |file|
+          destructo(file)
+        end
+      end
+
+      def flush
+        return if @properties.empty?
+        update do |file|
+          destructo(file)
+          accio(file)
+        end
+      end
+
+      def ttl
+        query.first[:ttl]
+      end
+
+      def ttl=(ttl)
+        @properties[:ttl] = ttl
+      end
+
+    private
+
+      def update(&block)
+        file = Tempfile.new('dns_rr-nsupdate-')
+        file.write "server #{server}\n"
+        file.write "zone #{zone}\n" unless zone.nil?
+        yield file
+        file.write "send\n"
+        file.close
+        if keyed?
+          nsupdate('-y', tsig_param, file.path)
+        else
+          nsupdate(file.path)
+        end
+        file.unlink
+      end
+
+      def accio(file)
+        newdata.each do |datum|
+          file.write "update add #{name}. #{resource[:ttl]} #{rrclass} #{type} #{datum}\n"
+        end
+      end
+
+      def destructo(file)
+        rrdata.each do |datum|
+          file.write "update delete #{name}. #{ttl} #{rrclass} #{type} #{datum}\n"
+        end
+      end
+
+      def server
+        resource[:server]
+      end
+
+      def zone
+        resource[:zone]
+      end
+
+      def keyname
+        resource[:keyname]
+      end
+
+      def hmac
+        resource[:hmac]
+      end
+
+      def secret
+        resource[:secret]
+      end
+
+      def keyed?
+        !secret.nil?
+      end
+
+      def tsig_param
+        "#{hmac}:#{keyname}:#{secret}"
+      end
+
+      def query
+        unless @query
+          if keyed?
+            dig_text = dig("@#{server}", '+noall', '+answer', name, type, '-c', rrclass, '-y', tsig_param)
+          else
+            dig_text = dig("@#{server}", '+noall', '+answer', name, type, '-c', rrclass)
+          end
+          @query = dig_text.lines.map do |line|
+            linearray = line.chomp.split(/\s+/, 5)
+            {
+              :name    => linearray[0],
+              :ttl     => linearray[1],
+              :rrclass => linearray[2],
+              :type    => linearray[3],
+              :rrdata  => linearray[4]
+            }
+          end.select do |record|
+            record[:name] == "#{name}."
+          end
+        end
+        @query
+      end
+
+    end
+  end
+end