redis.exceptions.ConnectionError：连接到容器中的 redis 服务器时出错

问：

我创建了一个包含以下内容的 Dockerfile

FROM alpine

# Run commands to install additional software
RUN apk add --update redis

# Specify command to run when the container starts up
CMD ["redis-server"]

然后运行 docker build 并运行命令

docker build -t dkr/redis:latest .
docker run -p 6379:6379  dkr/redis

然后，当我尝试从主机连接到容器中运行的redis服务器时，出现以下错误。从主机连接到 Redis 的正确方法是什么？

import redis
r = redis.Redis(host='127.0.0.1', port=6379, decode_responses=True)
>>> r.set("visits", "1")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/staging/venv/lib/python3.7/site-packages/redis/commands/core.py", line 2341, in set
    return self.execute_command("SET", *pieces, **options)
  File "/staging/venv/lib/python3.7/site-packages/redis/client.py", line 533, in execute_command
    conn = self.connection or pool.get_connection(command_name, **options)
  File "/staging/venv/lib/python3.7/site-packages/redis/connection.py", line 1086, in get_connection
    connection.connect()
  File "/staging/venv/lib/python3.7/site-packages/redis/connection.py", line 276, in connect
    self.on_connect()
  File "/staging/venv/lib/python3.7/site-packages/redis/connection.py", line 386, in on_connect
    self.read_response()
  File "/staging/venv/lib/python3.7/site-packages/redis/connection.py", line 500, in read_response
    response = self._parser.read_response(disable_decoding=disable_decoding)
  File "/staging/venv/lib/python3.7/site-packages/redis/_parsers/resp2.py", line 15, in read_response
    result = self._read_response(disable_decoding=disable_decoding)
  File "/staging/venv/lib/python3.7/site-packages/redis/_parsers/resp2.py", line 25, in _read_response
    raw = self._buffer.readline()
  File "/staging/venv/lib/python3.7/site-packages/redis/_parsers/socket.py", line 115, in readline
    self._read_from_socket()
  File "/staging/venv/lib/python3.7/site-packages/redis/_parsers/socket.py", line 68, in _read_from_socket
    raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
redis.exceptions.ConnectionError: Connection closed by server.