获取 python docker 容器与 redis docker 容器交互
问题描述
我是 docker、redis 和任何类型的网络的新手，(我至少知道 python！).首先，我想出了如何获取 redis docker 映像并在 docker 容器中运行它:
I'm new to docker, redis and any kind of networking, (I know python at least!). Firstly I have figured out how to get a redis docker image and run it in a docker container:
docker run --name some-redis -d redis
据我了解，此 redis 实例具有可用于连接其他容器的端口 6379.
As I understand this redis instance has port 6379 available to connect to other containers.
docker network inspect bridge
"Containers": {
"2ecceba2756abf20d5396078fd9b2ecf0d60ab04ca6b8df5e1b631b6fb5e9a85": {
"Name": "some-redis",
"EndpointID": "09f0069dae3632a2456cb4d82ad5e7c9782a2b58cb7a4ee655f57b5c410c3e87",
"MacAddress": "02:42:ac:11:00:02",
"IPv4Address": "172.17.0.2/16",
"IPv6Address": ""
}
如果我运行以下命令，我可以与 redis 实例交互并生成键:值对:
If I run the following command I can interact with the redis instance and generate key:value pairs:
docker run -it --link some-redis:redis --rm redis redis-cli -h redis -p 6379
set 'a' 'abc'
>OK
get 'a'
>"abc"
quit
我已经知道如何制作和运行安装了 redis 库的 docker 容器，该容器将运行以下 python 脚本:
I have figured out how to make and run a docker container with the redis library installed that will run a python script as follows:
这是我的 Dockerfile:
Here is my Dockerfile:
FROM python:3
ADD redis_test_script.py /
RUN pip install redis
CMD [ "python", "./redis_test_script.py" ]
这里是redis_test_script.py:
Here is redis_test_script.py:
import redis
print("hello redis-py")
构建 docker 镜像:
Build the docker image:
docker build -t python-redis-py .
如果我运行以下命令，脚本将在其容器中运行:
If I run the following command the script runs in its container:
docker run -it --rm --name pyRed python-redis-py
并返回预期的:
>hello redis-py
看起来两个容器都工作正常，问题是将它们连接在一起，我想最终使用python对redis容器执行操作.如果我按如下方式修改脚本并为 python 容器重建图像，它将失败:
It seems like both containers are working ok, the problem is connecting them both together, I would like to ultimately use python to perform operation on the redis container. If I modify the script as follows and rebuild the image for the python container it fails:
import redis
print("hello redis-py")
r = redis.Redis(host="localhost", port=6379, db=0)
r.set('z', 'xyz')
r.get('z')
我收到几个错误:
...
OSError: [Errno 99] Cannot assign requested address
...
redis.exceptions.ConnectionError: Error 99 connecting to localhost:6379. Cannot assign requested address.
.....
看起来他们没有连接，我再次尝试在 python 脚本中使用网桥 IP:
It looks like they're not connecting, I tried again using the bridge IP in the python script:
r = redis.Redis(host="172.17.0.0/16", port=6379, db=0)
并得到这个错误:
redis.exceptions.ConnectionError: Error -2 connecting to 172.17.0.0/16:6379. Name or service not known.
我尝试了redis子IP:
and I tried the redis sub IP:
r = redis.Redis(host="172.17.0.2/16", port=6379, db=0)
我得到这个错误:
redis.exceptions.ConnectionError: Error -2 connecting to 172.17.0.2/16:6379. Name or service not known.
感觉好像我从根本上误解了如何让容器相互通信的一些东西.我已经阅读了很多文档和教程，但正如我所说，没有网络经验并且以前没有使用过 docker，所以任何有用的解释和/或解决方案都会非常棒.
It feels like I'm fundamentally misunderstanding something about how to get the containers to talk to each other. I've read quite a lot of documentation and tutorials but as I say have no networking experience and have not previously used docker so any helpful explanations and/or solutions would be really great.
非常感谢
解决方案
这就是 Docker 网络的全部内容.快速解决方案 - 对两个容器使用 host 网络模式.缺点是隔离度低，但你会得到它的快速工作:
That's all about Docker networking. Fast solution - use host network mode for both containers. Drawback is low isolation, but you will get it working fast:
docker run -d --network=host redis ...
docker run --network=host python-redis-py ...
然后从 python 连接到 redis 只需使用 localhost 作为主机名.
Then to connect from python to redis just use localhost as a hostname.
更好的解决方案是使用docker用户定义的桥接网络
Better solution is to use docker user-defined bridge network
# create network
docker network create foo
docker run -d --network=foo --name my-db redis ...
docker run --network=foo python-redis-py ...
请注意，在这种情况下，您不能使用 localhost 而是使用 my-db 作为主机名.这就是我在启动第一个容器时使用 --name my-db 参数的原因.在用户定义的桥接网络中，容器通过名称相互连接.
Note that in this case you cannot use localhost but instead use my-db as a hostname. That's why I've used --name my-db parameter when starting first container. In user-defined bridge networks containers reach each other by theirs names.
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