instantbox/cron

Run cron jobs inside a container

Installed packages

• dcron
• curl
• wget
• rsync
• ca-certificates

Environment variables

CRON_STRINGS - string 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 is running in foreground

Cron files

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

At runtime, files in /etc/cron.d will copied to /var/spool/cron/crontab.

If present, CRON_STRINGS will create /var/spool/cron/crontab/CRON_STRINGS.

Simple usage

docker run -d \
  -v /path/to/app/conf/crontabs:/etc/cron.d \
  -v /path/to/app/scripts:/scripts \
  instantbox/cron

With scripts and CRON_STRINGS

docker run -d \
  -e 'CRON_STRINGS=* * * * * root /scripts/myapp-script.sh'
  -v /path/to/app/scripts:/scripts \
  instantbox/cron

Get URL by cron every minute

docker run -d \
  -e 'CRON_STRINGS=* * * * * root wget https://example.com/job'
  instantbox/cron

Log files

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