Returns worker node IPs for given configuration file.

def get_worker_node_ips(config_file, override_cluster_name):
    """Returns worker node IPs for given configuration file."""

    config = yaml.load(open(config_file).read())
    if override_cluster_name is not None:
        config["cluster_name"] = override_cluster_name

    provider = get_node_provider(config["provider"], config["cluster_name"])
    try:
        nodes = provider.non_terminated_nodes({TAG_RAY_NODE_TYPE: "worker"})

        if config.get("provider", {}).get("use_internal_ips", False) is True:
            return [provider.internal_ip(node) for node in nodes]
        else:
            return [provider.external_ip(node) for node in nodes]
    finally:
        provider.cleanup()