cron - Inside Docker container, cronjobs are not getting executed -

i have made docker image, dockerfile, , want cronjob executed periodically when container based on image running. dockerfile (the relevant parts):

from l3iggs/archlinux:latest  copy source /srv/visitor  workdir /srv/visitor  run pacman -syyu --needed --noconfirm \         && pacman -s --needed --noconfirm make gcc cronie python2 nodejs phantomjs \         && printf "*/2 * * * *       node /srv/visitor/visitor.js \n" >> cronjobs \         && crontab cronjobs \         && rm cronjobs \         && npm install -g node-gyp \         && python=/usr/sbin/python2 && export python \         && npm install  expose 80  cmd ["/bin/sh", "-c"] 

after creation of image run container , verify indeed cronjob has been added:

crontab -l  */2 * * * *     node /srv/visitor/visitor.js 

now, problem cronjob never executed. have, of course, tested "node /srv/visitor/visitor.js" executes when run manually console.

any ideas?

it's little tricky answer definitively, don't have time test, have various options open you:

• you use phusion base image, comes init system , cron installed. based on ubuntu , comparatively heavyweight (at least compared archlinux) https://registry.hub.docker.com/u/phusion/baseimage/

• if you're happy have started cron jobs, start cron cmd , keep in foreground (cron -f).

• you can use lightweight process manager start cron , whatever other processes need (phusion use runit, docker seem recommend supervisor).

• you write own cmd or entrypoint script starts cron , process. issue need careful handle signals or may end zombie processes.

in case, if playing around, i'd go last option, if it's more serious, i'd go process manager.