How to get CRON to call in the correct PATHs

Solution 1:

I used /etc/crontab. I used vi and entered in the PATHs I needed into this file and ran it as root. The normal crontab overwrites PATHs that you have set up. A good tutorial on how to do this.

The systemwide cron file looks like this:

This has the username field, as used by /etc/crontab.
# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file.
# This file also has a username field, that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user   command
42 6 * * *   root    run-parts --report /etc/cron.daily
47 6 * * 7   root    run-parts --report /etc/cron.weekly
52 6 1 * *   root    run-parts --report /etc/cron.monthly
01 01 * * 1-5 root python /path/to/file.py

Solution 2:

Most likely, cron is running in a very sparse environment. Check the environment variables cron is using by appending a dummy job which dumps env to a file like this:

* * * * * env > env_dump.txt

Compare that with the output of env in a normal shell session.

You can prepend your own environment variables to the local crontab by defining them at the top of your crontab.

Here's a quick fix to prepend $PATH to the current crontab:

# echo PATH=$PATH > tmp.cron
# echo >> tmp.cron
# crontab -l >> tmp.cron
# crontab tmp.cron

The resulting crontab will look similar to chrissygormley's answer, with PATH defined before the crontab rules.