docker-cron

Run cron jobs inside docker container

Usage

With docker run

# docker pull vpsdance/cron
# docker run -it --rm vpsdance/cron sh -c 'date'
docker run -d -it --rm --name cron -e TZ=Asia/Shanghai -v $(pwd)/examples/1min:/etc/periodic/1min vpsdance/cron
# print logs
docker logs cron -f
# stop container
docker stop cron

With docker-compose

# docker-compose.yml
version: '3'

services:
  cron:
    image: vpsdance/cron
    environment:
      - TZ=Asia/Shanghai
    volumes:
      - ./cron_tasks/1min:/etc/periodic/1min
      - ./cron_tasks/15min:/etc/periodic/15min
      - ./cron_tasks/hourly:/etc/periodic/hourly
      - ./cron_tasks/daily:/etc/periodic/daily
      - ./cron_tasks/weekly:/etc/periodic/weekly
      - ./cron_tasks/monthly:/etc/periodic/monthly
      # - ~/.ssh:/root/.ssh # ssh keys

• docker-compose up -d --force-recreate start
• docker logs cron -f print logs
• docker-compose stop stop
• For custom cron schedule, please refer to the examples folder.

FAQs

• Cron job format

# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * <command to execute>

• Print cron jobs

crontab -l
cat /etc/crontabs/root
ls /etc/periodic