deck-chores

A job scheduler for Docker containers, configured via container labels.

• Documentation: https://deck-chores.readthedocs.io
• Image repository: https://hub.docker.com/r/funkyfuture/deck-chores
• Code repository: https://github.com/funkyfuture/deck-chores
• Issue tracker: https://github.com/funkyfuture/deck-chores/issues
• Free software: ISC license

Features

• define regular jobs to run within a container context with container and optionally with image labels
• use date, interval and cron-like triggers
• set a maximum of simultaneously running instances per job
• restrict job scheduling to one container per service
• multi-architecture image supports amd64, arm64 and armv7l platforms, no emulator involved

Example

Let's say you want to dump the database of a Wordpress once a day. Here's a docker-compose.yml that defines a job that will be handled by deck-chores:

version: "3.7"

services:
  wordpress:
    image: wordpress
  mysql:
    image: mariadb
    volumes:
      - ./database_dumps:/dumps
    labels:
      deck-chores.dump.command: sh -c "mysqldump --all-databases > /dumps/dump-$$(date -Idate)"
      deck-chores.dump.interval: daily

It is however recommended to use scripts with a proper shebang for such actions. Their outputs to stdout and stderr as well as their exit code will be logged by deck-chores.

Maintenance

The final release is supposed to receive monthly updates that includes updates of all updateable dependencies. If one is skipped, don't worry. When a second maintenance release is skipped, feel free to open an issue to ask what the status is.

You can always build images upon an up-to-date base image with:

make build

Limitations

When running on a cluster of Docker Swarm nodes, each deck-chores instance can only observe the containers on the node it's running on, and hence only restrict to run one job per service within the node's context.

Acknowledgements

It wouldn't be as charming to write this piece of software without these projects:

• APScheduler for managing jobs
• cerberus for processing metadata
• docker-py for Docker interaction
• flake8, mypy, pytest and tox for testing
• Python

Authors

• Frank Sachsenheim (maintaining)
• aeri4list
• alpine-digger
• Brynjar Smári Bjarnason