Crontab on Amazon EC2 Server

Question

I have been trying for a while now to setup a cron job on EC2 at no luck at all. Although the cron job is listed and runs, it just doesn't find the file.

Here is the cron job

*/5 * * * * python /home/ec2-user/monitoring/job.py  >> /var/log/script_output.log 2>&1

What is the content of /var/log/script_output.log after the cron job runs? — Nigel Tufnel, Jan 09 '14 at 09:40
@Nigel : It isn't being created because permission is denied. — Mostafa Mahmoud, Jan 09 '14 at 09:56
As a quick and dirty solution you can `sudo touch /var/log/script_output.log && sudo chmod 0777 /var/log/script_output.log`. That'll give everyone permission to do anything with script_output.log — Nigel Tufnel, Jan 09 '14 at 10:07
The script isn't executing at the first place and this is the real issue. — Mostafa Mahmoud, Jan 09 '14 at 11:30

score 4 · Accepted Answer · edited May 23 '17 at 12:09

It seems what we've got here is one of those rare cases when cron job doesn't run.

Here's how I would tackle this problem.

I would run python /home/ec2-user/monitoring/job.py >> /var/log/script_output.log 2>&1 in bash. Just to check that the command can run in normal circumstances.
I would add MAILTO=your@email. Just to get emails when something goes wrong.
I would run which python command and use full path to python in the cron file. Let's say which python returned /usr/bin/python. Then I would edit cron file like this: */5 * * * * /usr/bin/python /home/ec2-user/monitoring/job.py >> /var/log/script_output.log 2>&1
I would append an empty line to the cron file. Actually I would do this first. But I'm stuck on FreeBSD's default cron. You're probably running Ubuntu and using Vixie Cron. Couldn't hurt anyway.
I would run pgrep cron in bash. Just to check that cron daemon is well and running.

In the end your cron should look like this:

MAILTO=my@email.com

*/5 * * * * /usr/bin/python /home/ec2-user/monitoring/job.py >> /var/log/script_output.log 2>&1

Crontab on Amazon EC2 Server

1 Answers1