Cron in a container
Run cron in a Docker container that can execute commands in other docker containers.
The image includes the docker client. Mount the host's docker socket /var/run/docker.sock to execute commands in other docker containers running on the host.
The cron container expects a crontab file in /cron/crontab unless otherwise specified with the CRONTAB environment variable. Provide your crontab file by mounting the containing directory on /cron.
Putting this all together in the example below.
docker run -v /tmp:/cron -v /var/run/docker.sock:/var/run/docker.sock -d --name cron bartt/cron:latest