Google Drive push notifications を hubot で受ける ref: http://qiita.com/hotakasaito/items/824b7612667e32328345

file0.coffee

  robot.router.post "/google/drive/notifications", (req, res) ->
    robot.logger.debug req
    # 何かしらの処理
    res.status(200).send 'ok'

file1.txt

openssl pkcs12 -in xxx.p12 -nocerts -passin pass:notasecret -nodes -out xxx.pem

file2.coffee

googleapis = require('googleapis')
drive = googleapis.drive({version: 'v2'})

SERVICE_ACCOUNT_EMAIL = 'xxx@developer.gserviceaccount.com'
SERVICE_ACCOUNT_KEY = 'xxx.pem'
SCOPE = [
  "https://www.googleapis.com/auth/drive",
  "https://www.googleapis.com/auth/drive.file",
  "https://www.googleapis.com/auth/drive.readonly",
  "https://www.googleapis.com/auth/drive.metadata.readonly",
  "https://www.googleapis.com/auth/drive.appdata",
  "https://www.googleapis.com/auth/drive.apps.readonly",
  "https://www.googleapis.com/auth/drive.metadata",
]

jwt = new googleapis.auth.JWT(SERVICE_ACCOUNT_EMAIL, SERVICE_ACCOUNT_KEY, null, SCOPE)
resource = {id: 'watch-001', type: 'web_hook', address: 'https://上記でプッシュ設定したドメイン/google/drive/notifications'}
jwt.authorize (err, tokens) ->
  if err
    console.log err
  else
    jwt.credentials = tokens
    drive.changes.watch {auth: jwt, resource: resource}, (err, resp) ->
    if err
      console.log err
    else
      console.log resp

file3.txt

2015-06-11T03:15:35.450146+00:00 heroku[router]: at=info method=POST path="/google/drive/notifications" host=xxx.herokuapp.com request_id=4660b262-e65b-42bc-bfad-06a9a290c292 fwd="xx.xx.xx.xx" dyno=web.1 connect=0ms service=6ms status=200 bytes=164