Docker django.db.utils.OperationalError：无法将主机名"db"转换为地址：名称解析暂时失败

Question

这似乎是一个常见错误。我遵循了关于Stackoverflow的每一个可能的建议(添加链接、网络等)，但在我的情况下没有什么不同。我在Windows上运行。

我的Dockerfile:

#Pull base image.
FROM python:3.9.5-slim
#Usefull to get logs
ENV PYTHONUNBUFFERED 1
#Make local dir
RUN mkdir -p /app
#set as the working directory
WORKDIR /app
#https://luis-sena.medium.com/creating-the-perfect-python-dockerfile-51bdec41f1c8
COPY requirements.txt .
#now copy all the files in this directory to code
ADD . .
#https://testdriven.io/blog/dockerizing-django-with-postgres-gunicorn-and-nginx/
RUN apt-get update && 
apt-get install -y postgresql-server-dev-all gcc python3-dev musl-dev && 
pip install -r requirements.txt && 
adduser --disabled-password --no-create-home app
USER app
#CMD python manage.py runserver
CMD gunicorn --bind 0.0.0.0:8000 app.wsgi:application -k eventlet

接下来，我的docker-compose.yml:

services:
web:
build: .
ports:
- "8000:8000"
volumes:
- .:/app
links:
- db:db
container_name: heritageapi_web_1
depends_on:
- db
networks:
- heritage-network
db:
image: postgres:13.3
container_name: db
restart: always
networks:
- heritage-network
environment:
POSTGRES_DATABASE: admin
POSTGRES_USER: root
POSTGRES_PASSWORD: root
POSTGRES_ROOT_PASSWORD: root
volumes:
- .dbdata:/var/lib/postgres
ports:
- "32768:5432"
networks:
heritage-network:
driver: bridge

我的.env:

DB_NAME=admin 
DB_USER=root 
DB_PASSWORD=root 
DB_HOST=db 
DB_PORT=5432

最后我的设置.py:

DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql',
'NAME': os.getenv('DB_NAME'),
'USER': os.getenv('DB_USER'),
'PASSWORD': os.getenv('DB_PASSWORD'),
'HOST': os.getenv('DB_HOST'),
'PORT': os.getenv('DB_PORT'),
}
}

Answer 1

我在web容器中没有看到.env文件。应该是这样的：

services:
web:
depends_on:
- db
env_file:
- .env.dev

如果一切正常，则使用docker-compose exec进入正在运行的docker容器并打印

python manage.py shell
>> from django.conf import settings
>> settings.DB_HOST