ModuleNotFoundError When Copying a Host Directory to Container in DockerFile - docker

Question

I'm going crazy trying to ADD a directory from my host machine to my docker container. When building the container with docker-compose up --build, it seems to ADD just fine, but when I try to access module in my app.py file, I get the ModuleNotFoundError
My DockerFile contains the following:
FROM python:3.7-alpine
RUN apk update && \
apk add --virtual build-deps gcc musl-dev && \
apk add --no-cache postgresql-dev && \
apk add alsa-lib-dev && \
apk add pulseaudio-dev && \
apk add postgresql-dev && \
apk add ffmpeg-dev && \
apk add ffmpeg && \
rm -rf /var/cache/apk/*
COPY /scraper/requirements.txt requirements.txt
RUN pip install -r requirements.txt
ADD /common/testmodel /scraper/testmodel
WORKDIR home/scraper/
ENTRYPOINT ["python3", "-u", "app.py"]
CMD gunicorn -b 0.0.0.0:5000 --access-logfile - "app:app"
Then when building the image, the log shows:
Step 6/9 : ADD /common/testmodel home/scraper/testmodel
---> a7b27854d751
My project structure looks like the following:
-common
-testmodel
-test.py
-scraper
-DockerFile
-requirements
-docker-compose.yml
But in my app.py file, when I run from testmodel.test import TestClass I get ModuleNotFoundError: No module named 'testmodel'
Any help with this problem is greatly appreciated as this how now taken up a much larger chunk of my day that I ever thought it would. Thank you very much.

Answer 1

I may be missing some context but I think you've several issues:
You COPY /scraper... and ADD /common... -- are these directories hanging from root on your local machine?
You set WORKDIR after COPY and ADD but generally (although not required), you'd set this first as a default destination and then you could COPY something . and ADD something . and these destinations (.) would refer to your WORKDIR
You use /home/scraper as your WORKDIR but you don't copy and add your files into it. It will be empty at this point.
Your ENTRYPOINT references app.py but your file is called test.py
One useful debugging tool is to shell into containers to e.g. examine the directory structure to confirm it's as expected. Assuming your image is called scraper, you could:
docker build \
--tag=scraper \
--file=scraper/Dockerfile \
. # Don't forget the period ;-)
Then Alpine's shell is called ash:
docker run \
--interactive \
--tty \
scraper:latest ash
Or, if your Dockerfile has an ENTRYPOINT, then override it using:
docker run \
--interactive \
--tty \
--entrypoint=ash \
scraper:latest
and then you could browse the container's directory structure:
You'll default to /home/scraper (WORKDIR):
/home/scraper # ls -l
total 0
You may examine /scraper using:
/home/scraper # apk install tree
/home/scraper # tree /scraper
/scraper
└── testmodel
└── test.py
1 directory, 1 file
I'm not entirely clear as to what would be the correct solution for you but I hope this helps get you progressed:
FROM python:3.7-alpine
RUN apk update && \
apk add --virtual build-deps gcc musl-dev && \
apk add --no-cache postgresql-dev && \
apk add alsa-lib-dev && \
apk add pulseaudio-dev && \
apk add postgresql-dev && \
apk add ffmpeg-dev && \
apk add ffmpeg && \
rm -rf /var/cache/apk/*
WORKDIR home/scraper/
COPY scraper/requirements.txt .
RUN pip install -r requirements.txt
ADD common/testmodel .
ENTRYPOINT ["python3", "-u", "test.py"]
CMD gunicorn -b 0.0.0.0:5000 --access-logfile - "test:app"