Integrity post-receive hook, safe for git 1.5.x and won't yak on merge commits

push-to-integrity-post-receive

#!/usr/bin/env ruby19

require 'net/http'
require 'uri'
require 'json'

# EDIT POST_RECEIVE_URL
POST_RECEIVE_URL = 'http://hostname:8910/repository-name/push'

old_head, new_head, ref = STDIN.gets.split
revision_text = `git rev-list --no-merges --pretty #{new_head} ^#{old_head}`
revisions = []
revision_text.split( /\n/ ).each_slice( 6 ) { |s|
  sha1 = s[0][ /commit (\w+)/, 1 ]
  s[1] =~ /Author: (\w+) <(.+?)>/
  author_name, author_email = $1, $2
  timestamp =  s[2][ /Date: +(.+?) -0/, 1 ]
  message = s[4..-1].join.strip

  revisions << {
    'id' => sha1,
    'author' => {
      'email' => author_email,
      'name' => author_name,
    },
    'message' => message,
    'timestamp' => timestamp,
  }

}

if revisions.empty?
  exit 0
end

payload = {
  'payload' => {
    "ref" => ref,
    "commits" => revisions,
  }.to_json
}


if pid = fork
  Process.detach pid
else
  Net::HTTP.post_form( URI.parse( POST_RECEIVE_URL ), payload )
end