execute bash command works but not on crontab

Question

I am using aws lightsail product.

When i execute on bash the commend,

* * * * * docker exec -it my_container_name Rscript /home/path/to/file.R

I also checked cron log using

grep CRON /var/log/syslog

and it says it worked fine. But the result is not given.

Try /path/to/docker instead of docker. Cron doesn't inherit your login environment. — keithpjolley, Jun 23 '18 at 20:08

score 1 · Accepted Answer · answered Jun 24 '18 at 04:54

1

Why run -it ?

Would it not be better to place the script in the container and run -d ?

Does the

Additional to that, your bash-env may be set up differently if you use cron rather than interactive login. PATHS , LC setting have caused me most issues.

answered Jun 24 '18 at 04:54

Tim Seed

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Glad it helped... was it the env due to running as a cron job ? – Tim Seed Jun 26 '18 at 00:43
I change *-it* to *-d*. then It worked only when the bash was running. – asbebe Jul 01 '18 at 07:51

score 0 · Answer 2 · answered Jul 04 '18 at 08:10

Does your dockerimage file have an ENTRYPOINT

i.e.

copy run2.sh /usr/local/bin/run2.sh
run chmod +x /usr/local/bin/run2.sh
ENTRYPOINT ["/usr/local/bin/run2.sh"]

Your run2.sh file should look something like this (so it can respond to Signals from the OS i.e. shutdown)

#!/bin/bash
#This is a run file - which should be used to add things you want your
#container to do when you start it up
#
#If you do not have this then ...
#  docker-compose up ---- simply exists as there is nothing for the container to do.

trap cleanup 1 2 3 6 9 15

cleanup()
{
  echo "Caught Signal ... cleaning up."
  service postgresql stop
  sleep 1s
  echo "Done  ... quitting."
  exit 1
}

service postgresql start
# wait forever
echo "Starting up"
while true
do
  tail -f /dev/null
done

Note: This removes the necessity to start services, plus you get to specify the shutdown steps required.

If you want you can have multiple rules, I was just lazy and lobbed them all together.

Hope this helps....

execute bash command works but not on crontab

2 Answers2