Docker [Errno 111] 连接调用失败 ('127.0.0.1', 6379)

Question

我正在尝试按照这里的教程 https://channels.readthedocs.io/en/latest/tutorial/part_2.html并检查通道层是否可以与 Redis 通信。我正在做的唯一不同的事情是我正在使用 docker-compose 并在 docker 容器上运行整个事情，这似乎把一切都搞砸了。这是我尝试时收到的错误消息

run async_to_sync(channel_layer.send)('test_channel', {'type': 'hello'})

Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/usr/local/lib/python3.7/site-packages/asgiref/sync.py", line 116, in __call__
    return call_result.result()
  File "/usr/local/lib/python3.7/concurrent/futures/_base.py", line 428, in result
    return self.__get_result()
  File "/usr/local/lib/python3.7/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
  File "/usr/local/lib/python3.7/site-packages/asgiref/sync.py", line 156, in main_wrap
    result = await self.awaitable(*args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/channels_redis/core.py", line 293, in send
    async with self.connection(index) as connection:
  File "/usr/local/lib/python3.7/site-packages/channels_redis/core.py", line 820, in __aenter__
    self.conn = await self.pool.pop()
  File "/usr/local/lib/python3.7/site-packages/channels_redis/core.py", line 70, in pop
    conns.append(await aioredis.create_redis(**self.host, loop=loop))
  File "/usr/local/lib/python3.7/site-packages/aioredis/commands/__init__.py", line 175, in create_redis
    loop=loop)
  File "/usr/local/lib/python3.7/site-packages/aioredis/connection.py", line 113, in create_connection
    timeout)
  File "/usr/local/lib/python3.7/asyncio/tasks.py", line 414, in wait_for
    return await fut
  File "/usr/local/lib/python3.7/site-packages/aioredis/stream.py", line 24, in open_connection
    lambda: protocol, host, port, **kwds)
  File "/usr/local/lib/python3.7/asyncio/base_events.py", line 958, in create_connection
    raise exceptions[0]
  File "/usr/local/lib/python3.7/asyncio/base_events.py", line 945, in create_connection
    await self.sock_connect(sock, address)
  File "/usr/local/lib/python3.7/asyncio/selector_events.py", line 473, in sock_connect
    return await fut
  File "/usr/local/lib/python3.7/asyncio/selector_events.py", line 503, in _sock_connect_cb
    raise OSError(err, f'Connect call failed {address}')
ConnectionRefusedError: [Errno 111] Connect call failed ('127.0.0.1', 6379)

我检查了一些帖子，看到很多人认为这是因为 Redis 没有运行。我知道 Redis 存在，因为 docker ps 显示

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
2ccab2cfc570        test_web            "python manage.py ru…"   7 minutes ago       Up 7 minutes        0.0.0.0:8000->8000/tcp   test_web_1
6da398f093fc        redis:2.8           "docker-entrypoint.s…"   10 minutes ago      Up 10 minutes       0.0.0.0:6379->6379/tcp   relaxed_aryabhata

知道我现在可以做什么吗？我对这些真的很陌生

Answer 1

尝试更改127.0.0.1:6379为redis:6379.

尽管 Redis 正在运行，但您的python容器无法与其通信；这是因为它正在尝试连接到127.0.0.1:6379，但从容器的角度来看，那里没有任何东西在运行。这对调试来说可能有点令人沮丧，但如果您记住容器有自己的网络命名空间，那就更容易了。结果，python's localhost != redis's localhost != 你主机的localhost.

幸运的是，连接共享同一网桥的容器很容易，默认情况下，docker-compose创建一个网桥网络并将所有容器连接到它们，提供必要的 DNS 以允许它们发现彼此。因此，容器到容器的通信只需使用服务名称即可。

需要注意的是，可以通过--net=container:<container-id>or--net=host标志在相同的命名空间中运行容器，并在主机的命名空间中运行容器。这是在一个容器中运行的调试工具，并将它们连接至其他容器或主机的网络命名空间，例如使用特别有用netshoot来看看有什么端口监听容器（便于暴露或不能）内docker run --rm -it --net container:test_web_1 nicolaka/netshoot netstat -tulpn。

Answer 2

尝试将 127.0.0.1:6379 更改为 redis:6379。

这个对我有用。只是一些细节

docker-compose.yml

...
  redis:
    image: redis:latest
    ports:
      - "6379:6379"
    volumes:
      - 'redisdata:/data'
....    

CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'channels_redis.core.RedisChannelLayer',
        'CONFIG': {
            "hosts": [('redis', 6379)],
        },
    },
}