两个独立的Flask应用程序在docker容器中通信

Question

编辑：

我设法使它工作，使用network_mode: "host"为两个容器，如下所示。现在还可以。然而，我觉得这是一个糟糕的黑客攻击，我想了解更多关于我的容器做错了什么，而不是黑客攻击。

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我的两个Flask应用程序在两个独立的Docker容器中通信时遇到问题。我已经在docker容器之外从m1运行了app.py，它是有效的，但显然需要做一些不同的事情来在docker集装箱之外进行通信。

我得到这个回溯：

Traceback (most recent call last):
m1_1  |   File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 2309, in __call__
m1_1  |     return self.wsgi_app(environ, start_response)
m1_1  |   File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 2295, in wsgi_app
m1_1  |     response = self.handle_exception(e)
m1_1  |   File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1741, in handle_exception
m1_1  |     reraise(exc_type, exc_value, tb)
m1_1  |   File "/usr/local/lib/python3.6/site-packages/flask/_compat.py", line 35, in reraise
m1_1  |     raise value
m1_1  |   File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 2292, in wsgi_app
m1_1  |     response = self.full_dispatch_request()
m1_1  |   File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1815, in full_dispatch_request
m1_1  |     rv = self.handle_user_exception(e)
m1_1  |   File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1718, in handle_user_exception
m1_1  |     reraise(exc_type, exc_value, tb)
m1_1  |   File "/usr/local/lib/python3.6/site-packages/flask/_compat.py", line 35, in reraise
m1_1  |     raise value
m1_1  |   File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1813, in full_dispatch_request
m1_1  |     rv = self.dispatch_request()
m1_1  |   File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1799, in dispatch_request
m1_1  |     return self.view_functions[rule.endpoint](**req.view_args)
m1_1  |   File "/app/app.py", line 11, in home
m1_1  |     res = requests.get(url)
m1_1  |   File "/usr/local/lib/python3.6/site-packages/requests/api.py", line 75, in get
m1_1  |     return request('get', url, params=params, **kwargs)
m1_1  |   File "/usr/local/lib/python3.6/site-packages/requests/api.py", line 60, in request
m1_1  |     return session.request(method=method, url=url, **kwargs)
m1_1  |   File "/usr/local/lib/python3.6/site-packages/requests/sessions.py", line 533, in request
m1_1  |     resp = self.send(prep, **send_kwargs)
m1_1  |   File "/usr/local/lib/python3.6/site-packages/requests/sessions.py", line 646, in send
m1_1  |     r = adapter.send(request, **kwargs)
m1_1  |   File "/usr/local/lib/python3.6/site-packages/requests/adapters.py", line 516, in send
m1_1  |     raise ConnectionError(e, request=request)
m1_1  | requests.exceptions.ConnectionError: HTTPConnectionPool(host='127.0.0.1', port=8002): Max retries exceeded with url: / (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7ff58dd1bd30>: Failed to establish a new connection: [Errno 111] Connection refused',))

m1 的app.py

from flask import Flask, jsonify
import requests
import json
app = Flask(__name__)

@app.route("/")
def home():
url = "http://127.0.0.1:8002/"
res = requests.get(url)
dictFromServer = res.json()
return dictFromServer['message']

if __name__=='__main__':
app.run(debug=True, host='0.0.0.0')

m2 的app.py

from flask import Flask, jsonify
app = Flask(__name__)

@app.route('/')
def hello_world():
return jsonify({ 'message': 'Hello From M2'})

if __name__=='__main__':
app.run(debug=True, host='0.0.0.0')

码头文件

FROM python:3.6-alpine
WORKDIR /app
COPY requirements.txt /app
COPY app.py /app
RUN pip install -r requirements.txt
EXPOSE 5000
ENTRYPOINT ["python"]
CMD ["app.py"]

码头工人组成

version: '3'
services:
m1:
build: m1
ports:
- "8001:5000"
m2:
build: m2
ports:
- "8002:5000"

Answer 1

Docker容器不使用相同的IP地址运行，因此m1中的127.0.0.1只解析为m1容器。

两个修复：

1. 两个容器的"network:host"将使用主机网络堆栈，因此m1和m2将具有相同的IP地址。"127.0.0.1"会起作用。

2. 将"127.0.0.1"替换为"m2"。这将使用内置的DNS服务器并解析m2容器的正确IP地址。这种方法还有一个额外的好处，即两个容器可以使用同一个端口，因为它们有不同的地址。