Docker Compose 找不到 pip 安装 package

Question

Docker Compose 给出ModuleNotFoundError: No module named 'django'错误。 Docker Compose has not installed my pip installed packages pip install -r requirements.txt but running the image any other way shows they are installed and this issue is only with docker-compose, why?

撰写

version: '3.8'

services:
  web:
    build: ./
    user: python
    volumes:
      - ./:/app
    ports:
      - 8000:8000
    env_file:
      - ./.env.dev

Dockerfile

# Base image  
FROM python:3.9.6

ENV HOME=/app

# create directory for the app user
RUN mkdir -p $HOME

# set work directory
WORKDIR $HOME
 
# install psycopg2 dependencies
RUN apt-get update \
    && apt-get -y install libpq-dev gcc \
    && pip install psycopg2 \
    && apt-get -y install gunicorn3

RUN pip install --upgrade pip
ADD requirements*.txt .
RUN pip install -r requirements.txt
COPY python . .

ENTRYPOINT ["/app/entrypoint.sh"]

EXPOSE 8000

问题：

我创建了以下 Dockerfile 它在生产中运行，甚至在 docker-compose 之外本地运行，没有任何问题，即以下工作没有任何错误docker run -p 8000:8000 web/lastest

但是，当我通过 docker-compose 运行它时，它找不到我安装的 pip 包。

例如：

• docker-compose 构建（成功）
• docker-compose向上

错误

web_1  | ImportError: Couldn't import Django. Are you sure it's installed and available on your PYTHONPATH environment variable? Did you forget to activate a virtual environment?
web_1  | [2022-01-04 14:55:05 +0000] [1] [INFO] Starting gunicorn 20.1.0
web_1  | [2022-01-04 14:55:05 +0000] [1] [INFO] Listening at: http://0.0.0.0:8000 (1)
web_1  | [2022-01-04 14:55:05 +0000] [1] [INFO] Using worker: sync
web_1  | [2022-01-04 14:55:05 +0000] [8] [INFO] Booting worker with pid: 8
web_1  | [2022-01-04 14:55:05 +0000] [8] [ERROR] Exception in worker process
web_1  | Traceback (most recent call last):
web_1  |   File "/usr/lib/python3/dist-packages/gunicorn/arbiter.py", line 589, in spawn_worker
web_1  |     worker.init_process()
web_1  |   File "/usr/lib/python3/dist-packages/gunicorn/workers/base.py", line 134, in init_process
web_1  |     self.load_wsgi()
web_1  |   File "/usr/lib/python3/dist-packages/gunicorn/workers/base.py", line 146, in load_wsgi
web_1  |     self.wsgi = self.app.wsgi()
web_1  |   File "/usr/lib/python3/dist-packages/gunicorn/app/base.py", line 67, in wsgi
web_1  |     self.callable = self.load()
web_1  |   File "/usr/lib/python3/dist-packages/gunicorn/app/wsgiapp.py", line 58, in load
web_1  |     return self.load_wsgiapp()
web_1  |   File "/usr/lib/python3/dist-packages/gunicorn/app/wsgiapp.py", line 48, in load_wsgiapp
web_1  |     return util.import_app(self.app_uri)
web_1  |   File "/usr/lib/python3/dist-packages/gunicorn/util.py", line 384, in import_app
web_1  |     mod = importlib.import_module(module)
web_1  |   File "/usr/lib/python3.9/importlib/__init__.py", line 127, in import_module
web_1  |     return _bootstrap._gcd_import(name[level:], package, level)
web_1  |   File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
web_1  |   File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
web_1  |   File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
web_1  |   File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
web_1  |   File "<frozen importlib._bootstrap_external>", line 790, in exec_module
web_1  |   File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
web_1  |   File "/app/app/wsgi.py", line 12, in <module>
web_1  |     from django.core.wsgi import get_wsgi_application
web_1  | ModuleNotFoundError: No module named 'django' 

在直接运行映像和使用 docker-compose 时运行which python输出/usr/local/bin/python 。

运行docker run -it 43d991d65c02 /bin/bash我可以看到并运行 Django。 只有在运行 docker-compose 时才没有安装 Django，为什么？

Answer 1

在提供的容器文件中，我们在容器目录/app中工作。 但是在运行时，我们将一个卷挂载到/app 。 因此，存储在/app中的映像构建期间生成的所有内容都会被卷安装覆盖。 如果运行时的依赖项安装在/app中，那么它们会被卷安装覆盖。

为了解决这个问题，我想到了两种可能性：

1. 我们可以删除卷挂载。 然而，这将使我们失去“热重载”的能力。

2. 我们可以在容器启动时重新运行pip install -r requirements.txt ，然后再启动应用程序。 这意味着将行pip install -r requirements.txt添加到entrypoint.sh -script。

Answer 2

当 docker-compose 将卷挂载到 /app 文件夹时，其先前的结构将被隐藏，新结构将覆盖先前的结构。