英文:
docker compose Flask app returning empty response
问题
我试图使用docker-compose玩一个包含flask的docker容器。这个flask应用是一个hello world应用，在我在主机上测试时可以正常工作。
docker-compose文件如下：
version: '3'
services:
web:
image: ubuntu
build:
context: ./
dockerfile: Dockerfile
ports:
- "6000:5000"
我的Dockerfile如下：
FROM ubuntu
RUN apt-get update
RUN apt-get install -y python3 python3-pip
RUN pip3 install Flask
COPY app.py .
EXPOSE 5000
CMD ["python3", "app.py"]
这个hello world应用看起来是这样的：
from flask import Flask, request
app = Flask(__name__)
@app.route("/")
def index():
return "Hello, World!"
if __name__ == "__main__":
app.run(debug=True)
当我使用docker-compose up -d启动容器时，没有错误。当我在localhost:6000上使用curl时，我得到了这个：
curl -X PUT localhost:6000
curl: (52) Empty reply from server
看起来应用正在响应，但与我在主机上运行时的响应方式不同，而是在curl时返回一个空字符串而不是"hello world"。我做错了什么？
英文:
I am trying to play with a dockerized flask container using docker-compose. The flask app is a hello world app that works correctly when I test it on my host.
The docker-compose file looks like this:
version: '3'
services:
web:
image: ubuntu
build:
context: ./
dockerfile: Dockerfile
ports:
- "6000:5000"
My dockerfile looks like this:
FROM ubuntu
RUN apt-get update
RUN apt-get install -y python3 python3-pip
RUN pip3 install Flask
COPY app.py .
EXPOSE 5000
CMD ["python3", "app.py"]
The hello world app looks like this:
from flask import Flask, request
app = Flask(__name__)
@app.route("/")
def index():
return "Hello, World!"
if __name__ == "__main__":
app.run(debug=True)
When I bring up the containers using docker-compose up -d, there is no error. When I curl to localhost:6000, I get this :
curl -X PUT localhost:6000
curl: (52) Empty reply from server
It seems like the app is responding but not how it responds when I run it on a my host and just returns an empty string instead of "hello world" when I curl to it. What am I doing wrong?
答案1
得分: 1
- 你需要使你的 Flask 应用可以外部访问：
app.run(host="0.0.0.0", debug=True)。 - 你正在使用
curl发送 PUT 请求，但你的应用只允许 GET 请求（这是默认设置，你可以在路由中添加允许的方法，像这样：@app.route("/", methods=["GET", "PUT"])）。 - 这个不是一个实际的 bug，而是一个建议：如果你需要你的应用能够被 Web 浏览器访问，请不要使用 6000 端口。至少其中一些浏览器会显示 ERR_UNSAFE_PORT 错误并阻止请求。不过，它会通过 curl 工作。
英文:
There are several issues here:
- You need to make your flask app accessible externally:
app.run(host="0.0.0.0", debug=True). - You are sending a PUT request from
curlbut your app only allows GET (this is the default, you can add allowed methods to your route like this:@app.route("/", methods=["GET", "PUT"]). - This one is not actually a bug but rather a recommendation: don't use port 6000 if you need your app to be accessible via web browsers. At least some of them will display an ERR_UNSAFE_PORT error and will block the request. It will work via curl though.
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