我正在尝试使用 Docker 构建 django 应用程序，但是当 docker 尝试 pip install -r 要求时，我收到以下消息：
Collecting Django==2.2.5 (from -r requirements.txt (line 1) WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x7ff789506828>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /simple/django/
这是我的 Dockerfile：
FROM python:3.6
ENV PYTHONUNBUFFERED 1
WORKDIR /app
COPY . /app
RUN pip install -r requirements.txt
我的 Linux 发行版：
Linux version 4.15.0-30deepin-generic (pbuilder@zs-PC) (gcc version 6.3.0 20170516 (Debian 6.3.0-18+deb9u1)) #31 SMP Fri …