kiwi-cron/README.md

kiwi-cron

kiwi - simple, consistent, powerful

Simple cron-jobs for kiwi-scp

Quick start

kiwi-cron comes with a (slightly) opinionated cron daemon config for periodic jobs. Just drop your scripts into the relevant directory under /kiwi-cron, that's it.

You will likely want to automate some tasks regarding your docker infrastructure. That's why the kiwi-cron images package a current docker-cli – you can just mount your docker.sock in its containers and use docker commands normally.

Time Zones

kiwi-cron images include the tzdata package and automatically handle /etc/localtime on startup. By default, "Etc/UTC" is set as the container time zone.

To use a different time zone, change the container environment variable TZ to your liking, e.g. "Europe/Berlin".

Simple jobs

On startup, kiwi-cron checks for possible job files in the /kiwi-cron directory structure.

For each subdirectory, a random valid cron schedule is generated, so that:

• /kiwi-cron/hourly runs once every hour (random minute)
• /kiwi-cron/daily runs once every day (random nighttime value between 9 pm and 3 am)
• /kiwi-cron/weekly runs once every weekend (random nighttime value on Saturday or Sunday)
• /kiwi-cron/monthly runs once every month (random nighttime value on a random day <= 28)
• /kiwi-cron/yearly and /kiwi-cron/annually runs once a year (random nighttime value on a random day <= 28 in January or February)

Cron schedules are regenerated once on each startup, only for directories that have files.

Granularity: The /kiwi-cron/every directory

Directories like /kiwi-cron/every/5_minutes will run scripts every 5 minutes. kiwi-cron picks up on that format and generates valid cron schedules on startup.

This way, you can define schedules to be run every N minutes, hours, days, or months by creating the corresponding directories.

Scheduling for every N weeks (or years) doesn't work though; jobs in those directories will instead be run every week (or every year).

Inspection

Checking the generated cron schedules is done using the standard crontab command: docker exec kiwi-cron-container crontab -l will show the effective schedules.