用Python连接到Redis集群(在Docker中)

Question

我正在设置一个高度可用的Redis集群(带有哨兵)，并且需要用Python向其写入数据。但是，我不知道在从Python连接时使用哪个主机名，而且我也收到了“连接拒绝”。

我的Dockerfile：

FROM redis:latest
ADD sentinel.conf /etc/redis/sentinel.conf
RUN chown redis:redis /etc/redis/sentinel.conf
ENV SENTINEL_QUORUM 2
RUN mkdir app
WORKDIR /app
ENV SENTINEL_DOWN_AFTER 5000
ENV SENTINEL_FAILOVER 10000
ENV SENTINEL_PORT 26000
ADD entrypoint.sh /usr/local/bin/
RUN chmod +x /usr/local/bin/entrypoint.sh
ENTRYPOINT ["entrypoint.sh"]
EXPOSE 26379 6379

FROM python:2.7-slim
WORKDIR /app
COPY . /app
RUN pip install --trusted-host pypi.python.org -r requirements.txt
CMD ["python", "app.py"]

docker-compose.yml

ervices:

  redis-master:
    container_name: redis-master
    image: redis:latest
    command: redis-server --port 6379
    ports:
      - "6379:6379"
    volumes:
      - .:/app

  redis-slave:
    container_name: redis-slave
    image: redis:latest
    command: redis-server --slaveof redis-master 6379 --protected-mode no
    volumes:
       - .:/app

  sentinel-1:
    container_name: sentinel-1
    build: sentinel
    environment:
      - SENTINEL_DOWN_AFTER=5000
      - SENTINEL_FAILOVER=5000

  sentinel-2:
    container_name: sentinel-2
    build: sentinel
    environment:
      - SENTINEL_DOWN_AFTER=5000
      - SENTINEL_FAILOVER=5000

  sentinel-3:
    container_name: sentinel-3
    build: sentinel
    environment:
      - SENTINEL_DOWN_AFTER=5000
      - SENTINEL_FAILOVER=5000

我试图运行的Python代码：

r = redis.StrictRedis(host='0.0.0.0', port=6379, db=0)
print ("set key1 123")
print (r.set('key1', '123'))
print ("get key1")
print(r.get('key1'))

错误：

Traceback (most recent call last):
  File "app.py", line 7, in <module>
    print (r.set('key1', '123'))
  File "/usr/local/lib/python2.7/site-packages/redis/client.py", line 1519, in set
    return self.execute_command('SET', *pieces)
  File "/usr/local/lib/python2.7/site-packages/redis/client.py", line 836, in execute_command
    conn = self.connection or pool.get_connection(command_name, **options)
  File "/usr/local/lib/python2.7/site-packages/redis/connection.py", line 1071, in get_connection
    connection.connect()
  File "/usr/local/lib/python2.7/site-packages/redis/connection.py", line 543, in connect
    raise ConnectionError(self._error_message(e))
redis.exceptions.ConnectionError: Error 111 connecting to 0.0.0.0:6379. Connection refused.

我试着把主机改为redis，redis-master，实际的码头IP，一些找不到，还有一些连接被拒绝。

我已经建立了一个网络，但是哨兵无法彼此沟通。

我也尝试用配置文件启动Redis，但错误是找不到它。为此，我添加了WORKDIR并将其复制到Dockerfile中。

如何从Python (也在Docker内部)连接Redis？

谢谢您的时间，任何建议都将不胜感激。

Answer 1

要从python连接，从同一个compose文件连接到container中：

r = redis.StrictRedis(host='redis-master', port=6379, db=0)

所以您需要使用service名称

如果Python Container不是来自同一个compose file，则可以使用redis compose中的network连接它，并在python撰写文件中将其声明为external。

使用docker run的示例

docker run -itd --network=MyNetworkFromTheOtherCompose busybox

使用compose的示例

networks:
  default:
    external:
      name: my-pre-existing-network-FromTheOtherCompose