README

Need to execute tasks on a schedule within a Docker environment?

Need to automate scheduled tasks for existing services?

Cronker brings the scheduling magic of cron to pretty much any Docker environment!

Notes

• Compatible with both standalone and Swarm mode
• Use crontab.guru for a quick and easy way to verify your cron syntax
• Use >> /proc/1/fd/1 2>&1 at the end of your cron task to have task logs output to standard out for viewing in service logs

How to Use

1. Use the below Docker Compose example for reference
2. Bind-mount a directory containing your cron task files to /cron and a directory containing any scripts you wish to use in cron tasks to /scripts
   • If acting on files on another containers volume, bind-mount the existing directory to cronker too to give access
3. Set PGID environment variable to desired group id (for file permissions)
4. Spin up the container
5. ???
6. Profit!

Examples

Docker Compose

services:
  cronker:
    image: ghcr.io/mitchnemirov/cronker:prod
    environment:
      - PGID=100
      - TZ=America/Los_Angeles
    volumes:
      - /path/to/cron/files:/cron
      - /path/to/scripts:/scripts
      - /path/to/existing/files:/path/to/existing/files # Optional; for working on other service bind-mounted directories

Cron Task

# Example: Execute script at midnight every day
0 * * * * su -s /bin/bash cronker -c "/scripts/script_to_run.sh" >> /proc/1/fd/1 2>&1
# Must include blank line at the end of the file

TO DO

• Run as non-root user
  • Semi-functional with su -s /bin/bash cronker -c in cron task execution.