from flask import Flask, make_response, jsonify
from flask.ext.principal import Principal

app = Flask(__name__)

Principal(app, use_sessions=False)

@app.route('/_ping')
@app.route('/v1/_ping')
def ping():
  response = make_response('true', 200)
  response.headers['X-Docker-Registry-Version'] = '0.6.0'
  return response