code: def replicate(ctx, args):
      
      slave = ClusterNode.from_uri(args.node)
      master = ClusterNode.from_uri(args.master)
      if not master.is_master():
          ctx.abort("Node {!r} is not a master.".format(args.master))
  
      try:
          slave.replicate(master.name)
      except redis.ResponseError as e:
          ctx.abort(str(e))
  
      Cluster.from_node(master).wait()
docs: Make node to be the slave of a master.