def containerIsRunning(container_name):
    """
    Checks whether the container is running or not.
    :param container_name: Name of the container being checked.
    :returns: True if status is 'running', False if status is anything else,
    and None if the container does not exist.
    """
    client = docker.from_env(version='auto')
    try:
        this_container = client.containers.get(container_name)
        if this_container.status == 'running':
            return True
        else:
            # this_container.status == 'exited', 'restarting', or 'paused'
            return False
    except NotFound:
        return None
    except requests.exceptions.HTTPError as e:
        logger.debug("Server error attempting to call container: ",
                      container_name)
        raise create_api_error_from_http_exception(e)
Checks whether the container is running or not.
    :param container_name: Name of the container being checked.
    :returns: True if status is 'running', False if status is anything else,
    and None if the container does not exist.