title: run openai gym with google compute engine
body: <p>I was trying to run the CartPole-v0 example on a Google Compute Engine VM.
  <a href="https://gym.openai.com/docs" rel="nofollow">https://gym.openai.com/docs</a></p>
  
  <pre><code>import gym
  env = gym.make('CartPole-v0')
  env.reset()
  for _ in range(1000):
      env.render()
      env.step(env.action_space.sample()) # take a random action
  </code></pre>
  
  <p>I have XQuartz installed, and ssh with -X.</p>
  
  <p>First, I was getting 
  pyglet.canvas.xlib.NoSuchDisplayException: Cannot connect to "None"</p>
  
  <p>Then according to <a href="http://www.gitterforum.com/discussion/openai-gym?page=28" rel="nofollow">http://www.gitterforum.com/discussion/openai-gym?page=28</a>, I use "xvfb-run -s "-screen 0 1400x900x24" /bin/bash"</p>
  
  <p>Then it ran fine with the result:</p>
  
  <pre><code>Making new env: CartPole-v0
  You are calling 'step()' even though this environment has already returned done = True. You should always call 'reset()' once you receive 'done = True' -- any further steps are undefined behavior
  </code></pre>
  
  <p>But there is nothing rendered...</p>