I am trying to test a simple cronjob and when I check if the cronjob has executed, it shows that it has but no file is being created as part of the task.
I have the following script, testjob.py which needs to be executed:
#!/usr/bin/env python3
import datetime
with open('testcron.txt', 'a') as outfile:
outfile.write('\n' + str(datetime.datetime.now() + 'myname'))
This is the cronjob:
#!/usr/bin/env python3
from crontab import CronTab
my_cron = CronTab(user='myname')
job = my_cron.new(command = 'python /Users/myname/Desktop/customers/cronjob/testjob.py')
#schedule job to run every 2 minutes
job.minute.every(1)
my_cron.write()
How can I troubleshoot this?
link to image with my crontab running via crontab -e: https://i.stack.imgur.com/pj9Pt.png
You can set up a cron job via crontab -e, which is much better than creating a python script to create a cron job. But anyways.
You can first troubleshoot by actually running your python script and seeing if there are any errors, and if the file is even created.
make sure the user for that cron job has the right permissions to execute the script.
try executing the command: python /Users/myname/Desktop/customers/cronjob/testjob.py directly from your terminal.
Judging from your response, the reason why its not working is because your script isn't able to open the text file.
When you're executing the script via: python /Users/myname/Desktop/customers/cronjob/testjob.py, the location of your text file "testcron.txt" depends entirely on where you are executing the script from.
So basically, unless "testcron.txt" is located in the same path / directory from where you are executing the script, its not going to work.
You can fix this by changing your cron tab to first navigate to where your text file is, and then run the python script.
For example, if your "testcron.txt" file is located in /Users/myname/Desktop/customers/cronjob/ then write your cron job as:
cd /Users/myname/Desktop/customers/cronjob && python ./testjob.py
You can instead of running the cron job with the python command run it like a shell script.
testjob.py:
#!/usr/bin/env python3
import datetime
with open('testcron.txt', 'a') as outfile:
outfile.write('\n' + str(datetime.datetime.now() + 'myname'))
Cronjob:
#!/usr/bin/env python3
from crontab import CronTab
my_cron = CronTab(user='myname')
job = my_cron.new(command = '/Users/myname/Desktop/customers/cronjob/testjob.py')
#schedule job to run every 2 minutes
job.minute.every(1)
my_cron.write()
Make sure you run chmod a+x /Users/myname/Desktop/customers/cronjob/testjob.py first to make the python executable.
Related
I am trying to modify the crontab of the root user through a script of python (main.py).
This script will open the crontab for root user and will modify it inserting a new command to call single.py with a parameter. The command used is not the problem as I have run it from the command line and it works. When I run the main.py script I can see the new entry when I run the crontab -l command. Everything looks correct but it does not work when is the time (nothing has been executed).
Doing some checks, if I execute the crontab -e command and I insert the command manually; when I save and close it; it shows: **crontab: installing new crontab** and then it works.
main.py:
fname = "/var/spool/cron/crontabs/root"
f = open(fname,"w+")
f.write("24 19 16 01 * python /home/pi/single.py 2087111972\n")
f.close() # save and close cron file
BTW: As this script has to be recursive (it will call itself for rescheduling its execution by modifying the crontab), is there anyway to apply the changes on crontab through the script?
Not sure what I'm doing wrong whether it's the code, the directory, or something else. Please help!
from crontab import CronTab
my_cron = CronTab(user='bgoldberg')
job = my_cron.new(command='python /Users/bgoldberg/PythonScripts/FunStuff/writeDate.py')
job.minute.every(1)
my_cron.write()
And here's the writeDate.py script:
import datetime
with open('dateInfo.txt','a') as outFile:
outFile.write('\n' + str(datetime.datetime.now()))
The writeDate.py script just writes the current timestamp to a txt file and it works fine when run separately. When I run python scheduleCron.py, it runs without error but it seems that it's not running the writeDate.py script because no txt file is created. When I enter crontab -l it correctly shows the job that was created: ***** python /Users/bgoldberg/PythonScripts/FunStuff/writeDate.py
Not sure what I'm doing wrong...
This is a cron "gotcha". Cron uses the command
python /Users/bgoldberg/PythonScripts/FunStuff/writeDate.py
which you expect to write to your current working directory, but cron will write to /var/log/syslog or some variation of this by default. It is trying to write to some place you don't have the permissions to (but it won't die), so you need to specifiy the absolute path of your output file.
changing your line in writeDate.py to write to an absolute path:
with open('/Users/bgoldberg/dateinfo.txt', 'a') as outFile:
will solve your problem.
I have below small python script
import os
os.system('kubectl get pods --context students-cmn')
when i run this command manually from terminal it is working , no issue , so i configured it to run as a cron job , but when cron job triggered getting below error
sh: kubectl: command not found
why , when the cronjob triggered , kubectl not working ?
can anyone please help
First of all, I imagine you are planning on adding code to your python script and that that is why you use python. I assume you used the crontab of the user that can run the command.
When you execute a command in cron you must specify the full path to the command. To find the full path to kubectl, you issue the following in Terminal:
which kubectl
It will print the full path.
Then, you edit your script (assuming the full path is "/opt/Kubernetes/bin"):
import os
os.system('/opt/Kubernetes/bin/kubectl get pods --context students-cmn')
i got the same issue when i tried to execute "kubectl" command into .sh/py file from CentOS 7 with cron.
i could run script .sh/.py file manually and the output was fine.
when i tried to set cron job with script, "kubectl" command could not be executed.
it didnot generate any logs for cron events.
if you dont mind, please support me.
crontab : * * * * * python /home/sanglv/kube-status.py >> /tmp/status.txt
kube-status.py file :
#!/usr/bin/env python
#ls command
import os
os.system('/usr/bin/kubectl get pods --all-namespaces --kubeconfig="/root/.kube/config"')
I try to run my python scrip at startup but it doesn't work.
Here is my python script(doesn't work):
#!/usr/bin/env python
import paho.mqtt.publish as publish
from datetime import datetime
t = str(datetime.now())
print t
with open("/home/james/mqtt/log.txt", "a+") as f:
f.write("it works " + t + "\n")
Here is my python script(works):
#!/usr/bin/env python
from datetime import datetime
t = str(datetime.now())
print t
with open("/home/james/mqtt/log.txt", "a+") as f:
f.write("it works " + t + "\n")
Here is my rc.local files(also try crontab and setting up service in /ect/init.d):
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
# /bin/mqtt_test.py &
# mosquitto_sub -t "mqtt"
/home/james/mqtt/script.sh
# /etc/mqtt/mqtt_test.py
exit 0
It look like by importing paho.mqtt.publish can make my script stop working, I am new to Linux, I have no idea why. Can someone help me out? Thanks for your help.
Ubuntu 16.04
Let me know if you need more info.
I have faced this problem myself. For me the problem was path. I could get it working by using a shell script to launch a python script and launch the shell script from crontab.
Here is my launcher.sh. You may not use sudo if you do not want. home/pi/record_data is the path where my file resides.
cd /
cd home/pi/record_data
sudo python record_video.py
In this case record_video.py is the python file I want to run at startup. In the crontab edit, I added this line below.
#reboot sh /home/pi/record_data/launcher.sh &
Do try this out if it work for you :) Good luck.
I have not got the logging the error into files working yet though.
it looks to me like you need to set/change the write permissions of the file before your python scrypt do this:
f.write("it works " + t + "\n")
for you is working because (maybe you are the owner of the file).
typical linux file permission is described as:
do use the chmod with the property flags, so linux has the rights to write the file too, please refer to the ubuntu help :)
I have a script that runs perfectly from command line:
/home/anaconda2/bin/python /project_folder/script.py
I added some details below:
$ echo $PYTHONPATH
:/project_folder/
$ which python
/home/anaconda2/bin/python
Which runs the script perfectly, flawlessly.
Then from within crontab (which has been successful for another script that didn't have local import issues) I can't get the script to run.
Crontab of code that doesn't work:
PYTHONPATH=/project_folder
* * * * * /home/anaconda2/bin/python /project_folder/script.py
Nothing happens. It's killing me and much of my time trying to figure this one out - any help much appreciated.
I resolved it via creating a wrapper shell script. Ugly in that i'm exporting the python path each time, but it works.
#!/bin/bash
export PYTHONPATH="${PYTHONPATH}:/project_folder"
source ~/.bash_profile
cd /project_folder && /my/anaconda/location/bin/python /project_folder/cript.py