add scirpt to return the default dkim record

bin/postal

@@ -62,6 +62,11 @@ case "$1" in
         run "bundle exec ruby script/generate_initial_config.rb"
         ;;
 
+    default-dkim-record)
+        run "bundle exec ruby script/default_dkim_record.rb"
+        ;;
+
+
     bundle)
         if [ -n "$2" ]; then
           run "bundle install --path=$2 --without=development --jobs=4 --clean"

lib/postal/config.rb

@@ -1,6 +1,7 @@
 require 'yaml'
 require 'pathname'
 require 'cgi'
+require 'openssl'
 require_relative 'error'
 require_relative 'version'
 
@@ -130,7 +131,7 @@ module Postal
     @signing_key ||= OpenSSL::PKey::RSA.new(File.read(signing_key_path))
   end
 
-  def self.amrp_dkim_dns_record
+  def self.rp_dkim_dns_record
     public_key = signing_key.public_key.to_s.gsub(/\-+[A-Z ]+\-+\n/, '').gsub(/\n/, '')
     "v=DKIM1; t=s; h=sha256; p=#{public_key};"
   end

script/default_dkim_record.rb

@@ -0,0 +1,2 @@
+require File.expand_path('../../lib/postal/config', __FILE__)
+puts Postal.rp_dkim_dns_record