new_contents: import sys
  from collections import defaultdict
  
  from paasta_tools.utils import get_docker_client
  
  
  def main():
      docker_client = get_docker_client()
      ip_to_containers = defaultdict(list)
  
      for container in docker_client.containers():
          networks = container['NetworkSettings']['Networks']
          if 'bridge' in networks:
              ip = networks['bridge']['IPAddress']
              if ip:
                  ip_to_containers[ip].append(container)
  
      output = []
      for ip, containers in ip_to_containers.items():
          if len(containers) > 1:
              output.append('{} shared by the following containers:'.format(ip))
              for container in containers:
                  output.append('    Image: {}'.format(container['Image']))
                  output.append('        ID: {}'.format(container['Id']))
                  output.append('        State: {}'.format(container['State']))
                  output.append('        Status: {}'.format(container['Status']))
              output.append('')
  
      if output:
          print('CRITICAL - There are multiple Docker containers assigned to the same IP.')
          print('There should only be one per IP. Choose one to keep and try stopping the others.')
          print('\n'.join(output))
          return 2
      else:
          print('OK - No Docker containers sharing an IP on this host.')
          return 0
  
  
  if __name__ == '__main__':
      sys.exit(main())
  
subject: Add script to monitor for containers sharing an IP