How to run OpenAI Gym .render() over a server

Question

I am running a python 2.7 script on a p2.xlarge AWS server through Jupyter (Ubuntu 14.04). I would like to be able to render my simulations.

Minimal working example<

Answer 1

I was looking for a solution that works in Colaboratory and ended up with this

from IPython import display
import numpy as np
import time

import gym
env = gym.make('SpaceInvaders-v0')
env.reset()

import PIL.Image
import io


def showarray(a, fmt='png'):
    a = np.uint8(a)
    f = io.BytesIO()
    ima = PIL.Image.fromarray(a).save(f, fmt)
    return f.getvalue()

imagehandle = display.display(display.Image(data=showarray(env.render(mode='rgb_array')), width=450), display_id='gymscr')

while True:
    time.sleep(0.01)
    env.step(env.action_space.sample()) # take a random action
    display.update_display(display.Image(data=showarray(env.render(mode='rgb_array')), width=450), display_id='gymscr')

EDIT 1:

You could use xvfbwrapper for the Cartpole environment.

from IPython import display
from xvfbwrapper import Xvfb
import numpy as np
import time
import pyglet
import gym
import PIL.Image
import io    

vdisplay = Xvfb(width=1280, height=740)
vdisplay.start()

env = gym.make('CartPole-v0')
env.reset()

def showarray(a, fmt='png'):
    a = np.uint8(a)
    f = io.BytesIO()
    ima = PIL.Image.fromarray(a).save(f, fmt)
    return f.getvalue()

imagehandle = display.display(display.Image(data=showarray(env.render(mode='rgb_array')), width=450), display_id='gymscr')


for _ in range(1000):
  time.sleep(0.01)
  observation, reward, done, info = env.step(env.action_space.sample()) # take a random action
  display.update_display(display.Image(data=showarray(env.render(mode='rgb_array')), width=450), display_id='gymscr')


vdisplay.stop()

If you're working with standard Jupyter, there's a better solution though. You can use the CommManager to send messages with updated Data URLs to your HTML output.

IPython Inline Screen Example

In Colab the CommManager is not available. The more restrictive output module has a method called eval_js() which seems to be kind of slow.