Source of docker image redmatter/cron designed to run scheduled tasks
using the classic vixie-cron (debian flavour).
The simplest way to make use of this image is to create a new image based on redmatter/cron, as shown in the example
inside the test folder.
You can either let the container run scheduled tasks as root user or you can add / modify another user. You can use
cron-user script within the base image to add this user and the specify the username in RUN_USER environment variable.
User for which crontab is to be added for; due to the way it is setup, choose a user other than any of the predefined users. The user chosen must be part of the crontab group. If a new user need to be added for this purpose, please use the cron-user add -u User [-g Group] command.
Since cron will execute the task in an isolated environment, any special environment variables set via ENV directive in your Dockerfile or from docker run -e option will not be available to your script. In order to get around that, you can specify a list of variable names separated by space.
You can add your crontab in this file; make sure any scripts and command referred in it are present in the container, either in the image or its volumes.