code: def start_monitor(config_file: str):
      cluster_config = _read_yaml(config_file)
  
      provider_config = cluster_config["provider"]
      assert provider_config["type"] == "fake_multinode_docker", (
          f"The docker monitor only works with providers of type "
          f"`fake_multinode_docker`, got `{provider_config['type']}`"
      )
  
      project_name = provider_config["project_name"]
  
      volume_dir = provider_config["shared_volume_dir"]
      os.makedirs(volume_dir, mode=0o755, exist_ok=True)
  
      # Create bootstrap config
      bootstrap_config_path = os.path.join(
          volume_dir, "bootstrap_config.yaml"
      )
      shutil.copy(config_file, bootstrap_config_path)
  
      # These two files usually don't exist, yet
      docker_compose_config_path = os.path.join(
          volume_dir, "docker-compose.yaml"
      )
  
      docker_status_path = os.path.join(volume_dir, "status.json")
  
      if os.path.exists(docker_compose_config_path):
          # We wait until this file exists, so remove it if it exists
          # from a previous run.
          os.remove(docker_compose_config_path)
  
      if os.path.exists(docker_status_path):
          os.remove(docker_status_path)
          # Create empty file so it can be mounted
          with open(docker_status_path, "wt") as f:
              f.write("{}")
  
      print(
          f"Starting monitor process. Please start Ray cluster with:\n"
          f"   RAY_FAKE_CLUSTER=1 ray up {config_file}"
      )
      monitor_docker(
          docker_compose_config_path, docker_status_path, project_name
      )
  
file_path: ray/python/ray/autoscaler/_private/fake_multi_node/docker_monitor.py
imports: import argparse
  import json
  import os
  import shutil
  import subprocess
  import time
  from typing import Any, Dict, List, Optional
  import yaml
label_desc: Use image node_id 6 for calling a global function with example usage: start_monitor(config_file) without return types