Run coverage test in a docker container - django

Question

I am trying to use the coverage tool to measure the code coverage of my Django app, when i test it work fine, but when i pushed to github, i got some errors in travis-ci:
Traceback (most recent call last):
File "/usr/local/bin/coverage", line 10, in <module>
sys.exit(main())
File "/usr/local/lib/python3.6/site-packages/coverage/cmdline.py", line 756, in main
status = CoverageScript().command_line(argv)
File "/usr/local/lib/python3.6/site-packages/coverage/cmdline.py", line 491, in command_line
return self.do_run(options, args)
File "/usr/local/lib/python3.6/site-packages/coverage/cmdline.py", line 641, in do_run
self.coverage.save()
File "/usr/local/lib/python3.6/site-packages/coverage/control.py", line 782, in save
self.data_files.write(self.data, suffix=self.data_suffix)
File "/usr/local/lib/python3.6/site-packages/coverage/data.py", line 680, in write
data.write_file(filename)
File "/usr/local/lib/python3.6/site-packages/coverage/data.py", line 467, in write_file
with open(filename, 'w') as fdata:
PermissionError: [Errno 13] Permission denied: '/backend/.coverage'
The command "docker-compose run backend sh -c "coverage run manage.py test"" exited with 1.
my travis.yml:
language: python
python:
- "3.6"
services:
- docker
before_script: pip install docker-compose
script:
- docker-compose run backend sh -c "python manage.py test && flake8"
- docker-compose run backend sh -c "coverage run manage.py test"
after_success:
- coveralls
and my dockerfile
FROM python:3.6-alpine
ENV PYTHONUNBUFFERED 1
# Install dependencies
COPY ./requirements.txt /requirements.txt
RUN apk add --update --no-cache postgresql-client jpeg-dev
RUN apk add --update --no-cache --virtual .tmp-build-deps \
gcc libc-dev linux-headers postgresql-dev musl-dev zlib zlib-dev
RUN pip install -r /requirements.txt
RUN apk del .tmp-build-deps
# Setup directory structure
RUN mkdir /backend
WORKDIR /backend
COPY scripts/start_dev.sh /
RUN dos2unix /start_dev.sh
COPY . /backend
RUN mkdir -p /vol/web/media
RUN mkdir -p /vol/web/static
RUN adduser -D user
RUN chown -R user:user /vol/
RUN chmod -R 755 /vol/web
USER user
docker-compose:
backend:
container_name: backend_dev_blog
build: ./backend
command: "sh -c /start_dev.sh"
volumes:
- ./backend:/backend
ports:
- "8000:8000"
networks:
- main
environment:
- DB_HOST=db
- DB_NAME=blog
- DB_USER=postgres
- DB_PASS=supersecretpassword
depends_on:
- db
So after seeing the lack of permissions on /.coverage, I simply added chmod +x .coverage, however, this made no difference and I yet received the exact same error.

Answer 1

Your permission issue is most likely due to the fact you have a volume (./backend:/backend) and that you are using a user in your container which does not have the right permission to write on this volume (USER user)
Since you probably cannot change the permissions on the Travis CI directory ./backend, you could try to change the user which is used to write files to that location. This is easy to do with docker-compose:
backend:
container_name: backend_dev_blog
build: ./backend
command: "sh -c /start_dev.sh"
user: root
volumes:
- ./backend:/backend
ports:
- "8000:8000"
networks:
- main
environment:
- DB_HOST=db
- DB_NAME=blog
- DB_USER=postgres
- DB_PASS=supersecretpassword
depends_on:
- db