docker-alpine-cron

A lightweight Docker image with Cron based on Alpine Linux.

Download size of this image is only:

Docker hub image: funnyzak/alpine-cron

Docker Pull Command: docker pull funnyzak/alpine-cron:latest

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.

Packages

The following packages are installed by default:

• certificates
• bash
• curl
• wget
• rsync
• git
• gcc
• openssh
• make
• cmake
• zip
• unzip
• gzip
• certbot
• bzip2
• tar
• tzdata
• nodejs
• yarn
• npm
• pushoo-cli
• mysql-client
• mariadb-connector-c
• ossutil64

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

Logs

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

Notification

The image already installed pushoo-cli, you can use it to send notification. You can send notification to DingTalk, iFttt, Discord, Feishu, atri, bark, etc.

More information about pushoo-cli, please refer to pushoo-cli and pushoo.

Usage

One Cron job

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

With scripts and CRON_STRINGS

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

Get URL by cron every minute

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

---

Compose

version: '3'
services:
  acron:
    image: funnyzak/alpine-cron
    privileged: true
    container_name: cron
    logging:
      driver: 'json-file'
      options:
        max-size: '1g'
    tty: true
    environment:
      - TZ=Asia/Shanghai
      - LANG=C.UTF-8
      - CRON_TAIL=1 # tail cron log
      - CRON_STRINGS=* * * * * /scripts/echo.sh
    restart: on-failure
    volumes:
      - ./scripts:/scripts # execute script
      - ./cron:/etc/cron.d # crontab
      - ./db:/db # log

For more details, please refer to the docker-compose.yml file.

Contribution

If you have any questions or suggestions, please feel free to submit an issue or pull request.

License

MIT License © 2022 funnyzak