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How to run Python script or other job in Docker container with CRON
In fact running cron jobs more comfortable when you work in host system. But some cases need to run scripts in containers.
Create folder with your project's name and create there four text files with following names:
File my_script.py need for run periodically. It may contain any code for your job. For example:
File named "cronjob" contain cron expression:
Now prepare Dockerfile:
In the end we need configure restart policy in docker-compose.yaml file:
Now we ready for run:
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
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
File named "cronjob" contain cron expression:
#####
*/5 * * * * /app/env/bin/python3 /app/my_script.py arg1 arg2 >> /app/logs/my_script.log 2>&1
#####
Now prepare Dockerfile:
# syntax=docker/dockerfile:1.9.0
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
In the end we need configure restart policy in docker-compose.yaml file:
services:
myproject:
restart: unless-stopped
build:
context: .
Now we ready for run:
docker compose up -d
