How to run periodic task using crontab inside docker container? - django

Question

I'm building Django+Angular web application which is deployed on server using docker-compose. And I need to periodically run one django management command. I was searching SO a bit and tried following:
docker-compose:
version: '3.7'
services:
db:
restart: always
image: postgres:12-alpine
environment:
POSTGRES_DB: ${DB_NAME}
POSTGRES_USER: ${DB_USER}
POSTGRES_PASSWORD: ${DB_PASSWORD}
ports:
- "5432:5432"
volumes:
- ./db:/var/lib/postgresql/data
api:
restart: always
image: registry.gitlab.com/*******/price_comparison_tool/backend:${CI_COMMIT_REF_NAME:-latest}
build: ./backend
ports:
- "8000:8000"
volumes:
- ./backend:/code
environment:
- SUPERUSER_PASSWORD=********
- DB_HOST=db
- DB_PORT=5432
- DB_NAME=price_tool
- DB_USER=price_tool
- DB_PASSWORD=*********
depends_on:
- db
web:
restart: always
image: registry.gitlab.com/**********/price_comparison_tool/frontend:${CI_COMMIT_REF_NAME:-latest}
build:
context: ./frontend
dockerfile: Dockerfile
volumes:
- .:/frontend
ports:
- "80:80"
depends_on:
- api
volumes:
backend:
db:
Dockerfile (backend):
FROM python:3.8.3-alpine
ENV PYTHONUNBUFFERED 1
RUN apk add postgresql-dev gcc python3-dev musl-dev && pip3 install psycopg2
RUN mkdir /code
WORKDIR /code
ADD requirements.txt /code/
ADD entrypoint.sh /entrypoint.sh
ADD crontab_task /crontab_task
ADD run_boto.sh /run_boto.sh
RUN chmod a+x /entrypoint.sh
RUN chmod a+x /run_boto.sh
RUN /usr/bin/crontab /crontab_task
RUN pip install -r requirements.txt
ADD . /code/
RUN mkdir -p db
RUN mkdir -p logs
ENTRYPOINT ["/entrypoint.sh"]
CMD ["gunicorn", "-w", "3", "--timeout", "300", "--bind", "0.0.0.0:8000", "--access-logfile", "-", "price_tool_project.wsgi>
crontab_task:
*/1 * * * * /run_boto.sh > /proc/1/fd/1 2>/proc/1/fd/2
run_boto.sh:
#!/bin/bash -e
cd price_comparison_tool/backend/
python manage.py boto.py
But when I run docker-compose up --build I get following messages in terminal:
api_1 | /bin/ash: python manage.py boto > /proc/1/fd/1 2>/proc/1/fd/2: not found
api_1 | /bin/ash: /run_boto.sh: not found
Project structure is following:
.
├── backend
├── db
├── docker-compose.yml
└── frontend
Can anybody give me an advice how to fix this issue and run management command periodically? Thanks in advance!
EDIT
I made following update:
crontab_task:
*/1 * * * * /code/run_boto.sh > /proc/1/fd/1 2>/proc/1/fd/2
and now run_boto.sh path is correct, but I get following error:
/bin/ash: /code/run_boto.sh: Permission denied

Answer 1

If you are running this application, not as a root user then the problem is, cron or crontab cannot be used as a non-rooted user.
you can take a look at this answer which I got when I was facing the same problem.