DEV Community

Shakhzhakhan Maxudbek
Shakhzhakhan Maxudbek

Posted on • Edited on • Originally published at args.tech

How to run Python script or other job in Docker container with CRON

After we're figured out the setup cron jobs in operating system, it's time to learn how to run any scripts in Docker container.

Create folder with your project's name and create there four text files with following names:

myproject/ - my_script.py - cronjob - Dockerfile - docker-compose.yaml
Enter fullscreen mode Exit fullscreen mode

File my_script.py need for run periodically. It may contain any code for your job. For example:

import requests r = requests.get(url='https://example.com/') if r.status_code == 200: # do something else: # do something else
Enter fullscreen mode Exit fullscreen mode

File named as cronjob should contain Cron expression:

##### */5 * * * * /app/env/bin/python3 /app/my_script.py arg1 arg2 >> /app/logs/my_script.log 2>&1 #####
Enter fullscreen mode Exit fullscreen mode

Attention! Last line in cronjob file shouldn't be empty!

Now prepare Dockerfile:

FROM debian:stable ENV PYTHONDONTWRITEBYTECODE=1 ENV PYTHONUNBUFFERED=1 USER root ARG APP=/app WORKDIR ${APP} RUN apt update RUN apt install nano cron python3 python3-pip python3-venv -y COPY . . COPY cronjob /etc/cron.d/cronjob RUN chmod 0644 /etc/cron.d/cronjob RUN crontab /etc/cron.d/cronjob RUN touch /var/log/cron.log RUN python3 -m venv ${APP}/env/ RUN ${APP}/env/bin/pip install --no-cache-dir -r ${APP}/requirements.txt CMD cron && tail -f /var/log/cron.log
Enter fullscreen mode Exit fullscreen mode

In the end we need configure restart policy in docker-compose.yaml file:

services: myproject: restart: unless-stopped build: context: .
Enter fullscreen mode Exit fullscreen mode

Now we ready for run:

docker compose up -d
Enter fullscreen mode Exit fullscreen mode

Top comments (0)