Ruby script interacting with the Amazon AWS CloudFront Custom Origin API

gistfile1.rb

#!/usr/bin/env ruby -w

require 'rubygems'
require 'hmac-sha1'
require 'net/https'
require 'base64'

AWS_KEY = '...'
AWS_SECRET = '...'

date = Time.now.utc
date = date.strftime("%a, %d %b %Y %H:%M:%S %Z")
digest = HMAC::SHA1.new(AWS_SECRET)
digest << date

uri = URI.parse("https://cloudfront.amazonaws.com/2010-11-01/distribution")

req = Net::HTTP::Post.new(uri.path)
req.initialize_http_header({
  'x-amz-date' => date,
  'Content-Type' => 'text/xml',
  'Authorization' => "AWS %s:%s" % [AWS_KEY, Base64.encode64(digest.digest)]
})
req.body = <<XML
<?xml version="1.0" encoding="UTF-8"?>
<DistributionConfig xmlns="http://cloudfront.amazonaws.com/doc/2010-11-01/">
  <CustomOrigin>
    <DNSName>%{origin_domain}</DNSName>
    <HTTPPort>80</HTTPPort>
    <HTTPSPort>443</HTTPSPort>
    <OriginProtocolPolicy>match-viewer</OriginProtocolPolicy>
  </CustomOrigin>
  <CallerReference>%{reference}</CallerReference>
  <Comment>%{comment}</Comment>
  <Enabled>true</Enabled>
</DistributionConfig>
XML
req.body = req.body % {
  origin_domain: '...',
  reference: "CF#{Time.now.utc.to_f.to_s.gsub('.', '')}",
  comment: '...'
}

puts req.body

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true
http.verify_mode = OpenSSL::SSL::VERIFY_NONE
res = http.request(req)

puts res.inspect
puts res.body
puts res.code