Ruby Git post-receive hook to update Pivotal Tracker

post-receive-pivotal.rb

#!/usr/bin/env ruby
# encoding: UTF-8
# file: hooks/post-receive-pivotal

require 'net/http'
require 'nokogiri'

# Ruby 1.8.7
class String
  def force_encoding(enc)
    self
  end
end

class GitLogs
  attr_accessor :raw_log, :logs
  def initialize old_ref, new_ref
    self.raw_log = `git log --no-color --format=short #{old_ref}..#{new_ref}`.force_encoding('utf-8')
    self.logs = []
    parse!
    self
  end

  def parse!
    regexp = /commit\ (.*)\nAuthor:\ (.*)\n\n\s*(.*)/i
    raw_log.scan(regexp).to_a.each do |match|
      self.logs << GitLog.new(match[0], match[1], match[2])
    end
  end

  def pivotal_sync!
    Pivotal.new(logs.reverse).send!
  end
end

class GitLog
  attr_accessor :raw_log, :hash, :author, :message
  def initialize hash, author, message
    self.hash = hash
    self.author = author
    self.message = message
  end

  def to_xml
    Nokogiri::XML::Builder.new do |xml|
      xml.source_commit {
        xml.commit_id self.hash
        xml.author self.author
        xml.message self.message
      } 
    end.to_xml
  end
end

class Pivotal
  attr_accessor :git_logs, :tracker_token
  BASE_URI = URI('http://www.pivotaltracker.com/')
  def initialize git_logs
    self.git_logs = git_logs
    self.tracker_token = get_token
  end

  def get_token
    `git config --get pivotal.token`.strip
  end

  def send!
    Net::HTTP.start(BASE_URI.host) do |http|
      git_logs.each do |git_log|
        request = Net::HTTP::Post.new('/services/v3/source_commits')
        request['X-TrackerToken'] = tracker_token
        request['Content-type'] = 'application/xml'
        request.body = git_log.to_xml
        response = http.request(request)
      end
    end
  end
end

out = STDIN.read
old_ref, new_ref, ref_name = out.split
GitLogs.new(old_ref, new_ref).pivotal_sync!

post-receive.sh

#!/bin/bash
# file: hooks/post-receive

while read oldrev newrev ref
do
  branch=`echo $ref | cut -d/ -f3`
  echo "Detected branch: $branch"

  #
  # Update Pivotal Tracker
  if [ "develop" == "$branch" ]; then
    echo "Updating Pivotal Tracker..."
    echo "$oldrev $newrev $ref" | ./post-receive-pivotal
  fi
done