Use JQ to parse environment variables from docker container and then transform them into arguments to be passing into the docker run command.

docker-vars.py

#!/usr/bin/env python

import argparse
import json
from subprocess import check_output

def inspect(container):
  return json.loads(check_output(["docker", "inspect", container]))

def prep_arg(string):
  return string.replace(' ', '\\ ').replace('\t', '').replace('\'', '\\\'');

def transform_to_args(env):
  filtered_env = filter((lambda x: not x.startswith('affinity:container')), env)
  return reduce((lambda acc, string: acc + (" -e %s" % prep_arg(string))), filtered_env, "");

def main():
  parser = argparse.ArgumentParser(description='Process some integers.')
  parser.add_argument('docker-id', type=str, help='Docker container id')

  args = vars(parser.parse_args())

  data = inspect(args['docker-id'])
  print transform_to_args(data[0]['Config']['Env'])

if __name__ == "__main__":
  main()