Failure in running Python script using a cron

Question

I am using the FreeBSD variant as seen below:

[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power: uname -a
FreeBSD ROUTER.local 10.1-RELEASE-p15 FreeBSD 10.1-RELEASE-p15 #0 c5ab052(releng/10.1)-dirty: Sat Jul 25 20:20:58 CDT 2015     root@pfs22-amd64-builder:/usr/obj.amd64/usr/pfSensesrc/src/sys/pfSense_SMP.10  amd64
[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power:

I have written a python script that runs sucessfully using the below commnd in CLI:

 /usr/local/bin/python2.7 /home/Script_to_monitor_power/power_alarm_t2.py

The python script contains a shebang line as below:

#!/usr/bin/env python2.7

The location of python2.7 is as below:

[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power: where python2.7
/usr/local/bin/python2.7
[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power:

My objective is to run the above script as a cronjob. So i make my script executable using

[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power: chmod +x power_alarm_t2.py

I have the edited the crontab as below:

[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power: crontab -l
* * * * * /usr/local/bin/python2.7 /home/Script_to_monitor_power/power_alarm_t2.py
[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power:

I also do:

[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power: cron reload
cron: cron already running, pid: 43420
[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power:

Now when i do:

[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power:   ps -ef | grep cron
[2.2.4-RELEASE][[email protected]]/home/Script_to_monitor_power:

Q: My cronjob is not running after every 1 min. Please suggest what am i missing?

Answer 1

The line in your cron should be:

* * * * * /home/Script_to_monitor_power/power_alarm_t2.py

If you run python from nonstandard location maybe is wise to wrap this python script in shell script and add PATH and LD_LIBRARY_PATH.

You can also try to make shell script and add this script in cron to make execution of python with explicit point to python executable and add your home environment variables:

#!/bin/bash
source ~/.bash_profile
/path/to/python /home/Script_to_monitor_power/power_alarm_t2.py