docker-alpine-cron-pi's Introduction

docker-alpine-cron

Dockerfile and scripts for creating image with Cron based on Alpine
Installed packages: dcron wget rsync ca-certificates

Environment variables:

CRON_STRINGS - strings with cron jobs. Use "\n" for newline (Default: undefined)
CRON_TAIL - if defined cron log file will read to stdout by tail (Default: undefined)
By default cron running in foreground

Cron files

/etc/cron.d - place to mount custom crontab files

When image will run, files in /etc/cron.d will copied to /var/spool/cron/crontab.
If CRON_STRINGS defined script creates file /var/spool/cron/crontab/CRON_STRINGS

Log files

Log file by default placed in /var/log/cron/cron.log

Simple usage:

docker run --name="alpine-cron-sample" -d \
-v /path/to/app/conf/crontabs:/etc/cron.d \
-v /path/to/app/scripts:/scripts \
xordiv/docker-alpine-cron

With scripts and CRON_STRINGS

docker run --name="alpine-cron-sample" -d \
-e 'CRON_STRINGS=* * * * * root /scripts/myapp-script.sh'
-v /path/to/app/scripts:/scripts \
xordiv/docker-alpine-cron

Get URL by cron every minute

docker run --name="alpine-cron-sample" -d \
-e 'CRON_STRINGS=* * * * * root wget https://sample.dockerhost/cron-jobs'
xordiv/docker-alpine-cron

Docker Compose

version: '2'
services:
  cron:
    image: adrum/docker-alpine-cron-pi
    volumes:
      - ./crons:/etc/cron.d
      - ./scripts:/scripts
      - ./logs:/logs
    environment:
      - 'CRON_STRINGS=* * * * * root /scripts/myapp-script.sh'

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