vipconsult/cron repository overview

if you don't need emails for the output from the cron jobs than you don't need the smtpContainer and the MAILTO env
# DOMAINNAME  is used for the email  FROM and TO  fields when cron sends the email

all envarionment variables set with the -e or in docker compose will also be set in the crontab file. This solve some weird command failures when we don't have the correct env vars. If you need to set some env vars in the container used to run the cron command you can use something like:
CRONTASK_1="* * * * *  root docker run debian bash -c "export CUSTOM_ENV=cron && echo '$CUSTOM_ENV 1 run from docker container'"

the default bridge network doesn't allow communication between containers without using 
the legacy --link switch so we creat a user defined network

docker network create cronApp

docker run -d \
	--name=smtpContainer \
	--net cronApp \
	-e DOMAINNAME=domain.com \
	-e SMTP_INTERVAL=1m \
	-e SMTP_PROCESSING=queue_only_load_latch \
	-e SMTP_remote_max_parallel=2 \
	-e SMTP_queue_run_max=3 \
	-e SMTP_timeout_frozen_after=3h \
	vipconsult/smtp

docker run -d \
	--name=cronContainer \
	--net cronApp \
	-v /var/run/docker.sock:/var/run/docker.sock:ro \
	-e DOMAINNAME=domain.com \
	-e DOCKER_API_VERSION=1.23 \
	-e SMTP_SERVER=smtpContainer \
	-e [email protected] \
	-e CRONTASK_1="* * * * *  root docker run debian echo 'Cron 1 run from docker container'" \
	-e CRONTASK_2="* * * * *  root docker run debian echo 'Cron 2 run from docker container'" \
	vipconsult/cron

version: '2'
services:
    cron:
		image: vipconsult/cron
		container_name: cronContainer
		volumes:
		    - /var/run/docker.sock:/var/run/docker.sock:ro
		environment:
		    - DOCKER_API_VERSION=1.23
		    - SMTP_SERVER=smtpContainer
		    - DOMAINNAME=domain.com
		    - [email protected]
		    - CRONTASK_1=* * * * *  root docker run debian echo 'Cron 1 run from docker container'
		    - CRONTASK_2=* * * * *  root docker run debian echo 'Cron 2 run from docker container'

    smtp:
		image: vipconsult/smtp
		container_name: smtpContainer
		environment:
		    - DOMAINNAME=domain.com
		    - SMTP_INTERVAL=1m
		    - SMTP_PROCESSING=queue_only_load_latch
		    - SMTP_remote_max_parallel=2
		    - SMTP_queue_run_max=3
		    - SMTP_timeout_frozen_after=3h
	

docker logs cronContainer
docker logs smtpContainer