git post-receive hook for pivotal tracker

pivotal-post-receive.rb

#!/usr/bin/env ruby

# git post-receive hook that posts the log messages to pivotal tracker
# for automatic updates of stories.
# See http://www.pivotaltracker.com/help/api?version=v3#scm_post_commit
# for more information

require "cgi"

begin
  require "patron"
rescue LoadError
  begin
    require "rubygems"
    require "patron"
  rescue LoadError
    puts "pivotal tracker notification requires the patron gem"
    exit 0
  end
end

ZERO = "0" * 40

if ENV["PIVOTAL_TRACKER_TOKEN"]
  api_token = ENV["PIVOTAL_TRACKER_TOKEN"]
else
  puts "set PIVOTAL_TRACKER_TOKEN in the environment to enable notification"
  exit 0
end

STDIN.readlines.each do |line|
  oldrev, newrev, refname = line.strip.split(" ")
  next if newrev == ZERO # deleting something

  # brand new branch
  range = oldrev == ZERO ? newrev : "#{oldrev}..#{newrev}"

  revisions = %x(git rev-list --pretty="%h%n%an%n%s%n%b%n" #{range}).split("\n\n\n")

  puts "notifying pivotal tracker of changes..."

  patron = Patron::Session.new
  patron.base_url = "http://www.pivotaltracker.com"
  patron.headers["X-TrackerToken"] = api_token
  patron.headers["Content-type"] = "application/xml"

  revisions.each do |revision|
    revision = revision.split("\n", 4)
    revision[0]           # "commit HASH"
    sha1 = revision[1]    # abbreviated sha1
    author = revision[2]  # author name
    message = revision[3] # commit message subject and body, newline-separated

    xml = "<source_commit>"
    xml << "<commit_id>" << sha1 << "</commit_id>"
    xml << "<author>" << CGI::escapeHTML(author) << "</author>"
    xml << "<message>" << CGI::escapeHTML(message) << "</message>"
    # xml << "<url>" << ... << "</url>"
    xml << "</source_commit>"

    r = patron.post("/services/v3/source_commits", xml)
    puts r.status_line unless r.status < 400
  end

end

exit 0