从 Dockerfile 运行 gunicorn 不起作用，但可以手动启动答案

【问题标题】：Running gunicorn from Dockerfile not working, but works with manual start从 Dockerfile 运行 gunicorn 不起作用，但可以手动启动
【发布时间】：2019-04-03 06:35:09
【问题描述】：

这是我的项目结构-

/app
  /config
  /controllers
  /lib
  /schemas
  /static
  /templates
  /tests
  __init__.py
Dockerfile
wsgi.py

这就是我的 Dockerfile 的样子

FROM python:3.6

WORKDIR /app

COPY ./requirements.txt /.requirements.txt

COPY . /app

# Install any needed packages specified in requirements.txt
RUN pip install -r requirements.txt

EXPOSE 8000

ENV FLASK_APP=iterative.py
ENV FLASK_ENV=development


CMD gunicorn -b 0.0.0.0:8000 -w 4 wsgi:app

这就是我的wsgi.py 的样子

from app import app

print("IS WSGI BEING RUN")
if __name__ == '__main__':
    print("IS THIS RUNNING")
    app.run(host="0.0.0.0", debug=True, threaded=True)

这就是我的__init.py 的样子

from flask import Flask
import sys
app = Flask(__name__)
from app import routes
print("IS INIT.PY RUNNING")

这就是我的工作

我运行 `docker build -t 。
然后我运行docker run 80:8000 <app_name>

这是我得到的输出

[2019-04-03 09:52:09 +0530] [8547] [INFO] Starting gunicorn 19.9.0
[2019-04-03 09:52:09 +0530] [8547] [INFO] Listening at: http://0.0.0.0:8000 (8547)
[2019-04-03 09:52:09 +0530] [8547] [INFO] Using worker: sync
[2019-04-03 09:52:09 +0530] [8550] [INFO] Booting worker with pid: 8550
[2019-04-03 09:52:09 +0530] [8551] [INFO] Booting worker with pid: 8551
[2019-04-03 09:52:09 +0530] [8552] [INFO] Booting worker with pid: 8552
[2019-04-03 09:52:09 +0530] [8553] [INFO] Booting worker with pid: 8553

请注意，没有打印语句出来。

然后我通过 ssh 进入 docker 容器

docker exec -it <container_id> /bin/bash

然后我运行（我在任意端口运行它只是为了证明它有效）

gunicorn -b 9000 -w 4 wsgi:app

现在这是我得到的输出

[2019-04-03 06:25:44 +0000] [30] [INFO] Starting gunicorn 19.9.0
[2019-04-03 06:25:44 +0000] [30] [INFO] Listening at: http://0.0.35.40:8000 (30)
[2019-04-03 06:25:44 +0000] [30] [INFO] Using worker: sync
[2019-04-03 06:25:44 +0000] [33] [INFO] Booting worker with pid: 33
[2019-04-03 06:25:44 +0000] [35] [INFO] Booting worker with pid: 35
/usr/local/lib/python3.6/site-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
  """)
[2019-04-03 06:25:44 +0000] [36] [INFO] Booting worker with pid: 36
/usr/local/lib/python3.6/site-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
  """)
[2019-04-03 06:25:44 +0000] [38] [INFO] Booting worker with pid: 38
/usr/local/lib/python3.6/site-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
  """)
FLASK ENVIRONMENT: development
IS INIT.PY RUNNING
IS WSGI BEING RUN
IS WSGI BEING RUN
/usr/local/lib/python3.6/site-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
  """)
FLASK ENVIRONMENT: development
IS INIT.PY RUNNING
IS WSGI BEING RUN
IS WSGI BEING RUN
FLASK ENVIRONMENT: development
IS INIT.PY RUNNING
IS WSGI BEING RUN
IS WSGI BEING RUN
FLASK ENVIRONMENT: development
IS INIT.PY RUNNING
IS WSGI BEING RUN
IS WSGI BEING RUN

我检查 docker 日志以确保容器的输出不只是写入日志。它不是。

为什么这两种情况的行为不同？

【问题讨论】：

标签： python docker gunicorn

【解决方案1】：

好的，这真的很令人沮丧，我希望这对其他人有所帮助。

那里的每个教程都没有强调运行 Docker 的操作系统。 Docker 并非在所有操作系统中都以相同的方式运行。

其实Mac OS，你只能通过localhost打你的容器。

https://docs.docker.com/docker-for-mac/networking/#known-limitations-use-cases-and-workarounds

【讨论】：