Unable to find ssl cert or key file in docker build

Question

I have a docker file that generates a flask app using gunicorn. For my purposes I need to use https so I'm setting up ssl using openssl. However I keep running into this error:

[2020-02-24 17:01:18 +0000] [1] [INFO] Starting gunicorn 20.0.4
Traceback (most recent call last):
  File "/usr/local/bin/gunicorn", line 11, in <module>
    sys.exit(run())
  File "/usr/local/lib/python3.6/dist-packages/gunicorn/app/wsgiapp.py", line 58, in run
    WSGIApplication("%(prog)s [OPTIONS] [APP_MODULE]").run()
  File "/usr/local/lib/python3.6/dist-packages/gunicorn/app/base.py", line 228, in run
    super().run()
  File "/usr/local/lib/python3.6/dist-packages/gunicorn/app/base.py", line 72, in run
    Arbiter(self).run()
  File "/usr/local/lib/python3.6/dist-packages/gunicorn/arbiter.py", line 198, in run
    self.start()
  File "/usr/local/lib/python3.6/dist-packages/gunicorn/arbiter.py", line 155, in start
    self.LISTENERS = sock.create_sockets(self.cfg, self.log, fds)
  File "/usr/local/lib/python3.6/dist-packages/gunicorn/sock.py", line 162, in create_sockets
    raise ValueError('certfile "%s" does not exist' % conf.certfile)
ValueError: certfile "server.crt" does not exist

Here is my Dockerfile:

FROM ubuntu:latest

RUN apt-get update && apt-get install python3-pip -y && \
    apt-get install python3-dev openssl


RUN openssl req -nodes -new -x509 -keyout server.key -out server.cert -subj "/C=US/ST=MD/L=Columbia/O=Example/OU=ExampleOU/CN=example.com/emailAddress=seanbrhn3@gmail.com"

COPY ./requirements.txt /app/requirements.txt

WORKDIR /app

RUN pip3 install -r requirements.txt

COPY . /app

ENV PORT 8080

CMD ["gunicorn", "--certfile=server.crt","--keyfile=server.key","app:app", "--config=config.py"]

All help is most appreciated!

Answer 1

I solved the problem instead of creating the cert and key in the dockerfile I used the copy command to take my cert and keys from my local directory and put it in the dockerfile. My problem was just my lack of knowledge of docker

Answer 2

This probably won't be the case for most people, but I wanted to put this out there just in case. I had this issue and realized that I had forgotten that I was mounting a volume in my docker run command.

So even though I was downloading files in my Dockerfile (during docker build ), as soon as I did docker run with the volume getting mounted (the volume did not contain those downloaded files) all the downloaded files would get deleted.