cron job decides for itself if it wants to run (ubuntu 18.04)












0















I recently wrote a python script that reminds me via email if I need to move my car for the street sweeper mafia (and avoid a ticket). When I ran the script from the command line, it worked every time. So I added it to crontab -e and tested it, it worked if I reset the date, time, etc.



I decided to run the cron tab every hour just for debug purposes:



1 * * * * python3 /home/robert/scripts/parking-project.py


On the night last week when the python script should have triggered the email, I was ready for the reminder. Instead there was no action.



I researched several cronjob articles to see how I messed up, but they all reinforced my original implementation decisions.



Eventually I got distracted and started working on other projects, but then today, out of the blue, my cronjob started working exactly like I expected it to.



more info




  • I had restarted the machine many times since implementing the job - so a reboot was not the answer.


  • my clock was correct


  • the script worked perfectly if you copied and pasted the command that was listed in crontab -e


  • journalctl -u cron.service reported that there was never any attempt to run the cronjob


  • internet access was not a factor



What could have made the cronjob suddenly decide to start working correctly?










share|improve this question




















  • 1





    Was your system, by chance, suspended/hibernated/off or simply logged off during the periods that the cronjobs did not run?

    – user535733
    7 hours ago











  • @user535733, yes, but not always. There were plenty of times when it should have run when it was online but didn't. I don't think this was a factor, but thank you for jumping in.

    – Robert Baker
    7 hours ago











  • wouldn't 1 * * * * mean the first minute of every hour? Remember, the notation is MM HH, not HH MM. Some versions of cron also require a username such as 00 01 * * * root /home/robert/scripts/parking-project.py. My server performs a bulk processing of security footage with a crontab, and it looks like this (ubuntu 16.04) 30 2 * * * root bash /mnt/array0/porch/process.sh

    – Minty
    4 hours ago













  • @Minty OP said "run [...] every hour", so that line is OK. The user crontab edited using crontab -e doesn't require a username (those commands run as your user). The username is required in system crontab files (/etc/cronatb, /etc/cron.d/*).

    – Olorin
    3 hours ago
















0















I recently wrote a python script that reminds me via email if I need to move my car for the street sweeper mafia (and avoid a ticket). When I ran the script from the command line, it worked every time. So I added it to crontab -e and tested it, it worked if I reset the date, time, etc.



I decided to run the cron tab every hour just for debug purposes:



1 * * * * python3 /home/robert/scripts/parking-project.py


On the night last week when the python script should have triggered the email, I was ready for the reminder. Instead there was no action.



I researched several cronjob articles to see how I messed up, but they all reinforced my original implementation decisions.



Eventually I got distracted and started working on other projects, but then today, out of the blue, my cronjob started working exactly like I expected it to.



more info




  • I had restarted the machine many times since implementing the job - so a reboot was not the answer.


  • my clock was correct


  • the script worked perfectly if you copied and pasted the command that was listed in crontab -e


  • journalctl -u cron.service reported that there was never any attempt to run the cronjob


  • internet access was not a factor



What could have made the cronjob suddenly decide to start working correctly?










share|improve this question




















  • 1





    Was your system, by chance, suspended/hibernated/off or simply logged off during the periods that the cronjobs did not run?

    – user535733
    7 hours ago











  • @user535733, yes, but not always. There were plenty of times when it should have run when it was online but didn't. I don't think this was a factor, but thank you for jumping in.

    – Robert Baker
    7 hours ago











  • wouldn't 1 * * * * mean the first minute of every hour? Remember, the notation is MM HH, not HH MM. Some versions of cron also require a username such as 00 01 * * * root /home/robert/scripts/parking-project.py. My server performs a bulk processing of security footage with a crontab, and it looks like this (ubuntu 16.04) 30 2 * * * root bash /mnt/array0/porch/process.sh

    – Minty
    4 hours ago













  • @Minty OP said "run [...] every hour", so that line is OK. The user crontab edited using crontab -e doesn't require a username (those commands run as your user). The username is required in system crontab files (/etc/cronatb, /etc/cron.d/*).

    – Olorin
    3 hours ago














0












0








0








I recently wrote a python script that reminds me via email if I need to move my car for the street sweeper mafia (and avoid a ticket). When I ran the script from the command line, it worked every time. So I added it to crontab -e and tested it, it worked if I reset the date, time, etc.



I decided to run the cron tab every hour just for debug purposes:



1 * * * * python3 /home/robert/scripts/parking-project.py


On the night last week when the python script should have triggered the email, I was ready for the reminder. Instead there was no action.



I researched several cronjob articles to see how I messed up, but they all reinforced my original implementation decisions.



Eventually I got distracted and started working on other projects, but then today, out of the blue, my cronjob started working exactly like I expected it to.



more info




  • I had restarted the machine many times since implementing the job - so a reboot was not the answer.


  • my clock was correct


  • the script worked perfectly if you copied and pasted the command that was listed in crontab -e


  • journalctl -u cron.service reported that there was never any attempt to run the cronjob


  • internet access was not a factor



What could have made the cronjob suddenly decide to start working correctly?










share|improve this question
















I recently wrote a python script that reminds me via email if I need to move my car for the street sweeper mafia (and avoid a ticket). When I ran the script from the command line, it worked every time. So I added it to crontab -e and tested it, it worked if I reset the date, time, etc.



I decided to run the cron tab every hour just for debug purposes:



1 * * * * python3 /home/robert/scripts/parking-project.py


On the night last week when the python script should have triggered the email, I was ready for the reminder. Instead there was no action.



I researched several cronjob articles to see how I messed up, but they all reinforced my original implementation decisions.



Eventually I got distracted and started working on other projects, but then today, out of the blue, my cronjob started working exactly like I expected it to.



more info




  • I had restarted the machine many times since implementing the job - so a reboot was not the answer.


  • my clock was correct


  • the script worked perfectly if you copied and pasted the command that was listed in crontab -e


  • journalctl -u cron.service reported that there was never any attempt to run the cronjob


  • internet access was not a factor



What could have made the cronjob suddenly decide to start working correctly?







bash scripts python cron






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited 3 hours ago









Olorin

2,433821




2,433821










asked 7 hours ago









Robert BakerRobert Baker

8210




8210








  • 1





    Was your system, by chance, suspended/hibernated/off or simply logged off during the periods that the cronjobs did not run?

    – user535733
    7 hours ago











  • @user535733, yes, but not always. There were plenty of times when it should have run when it was online but didn't. I don't think this was a factor, but thank you for jumping in.

    – Robert Baker
    7 hours ago











  • wouldn't 1 * * * * mean the first minute of every hour? Remember, the notation is MM HH, not HH MM. Some versions of cron also require a username such as 00 01 * * * root /home/robert/scripts/parking-project.py. My server performs a bulk processing of security footage with a crontab, and it looks like this (ubuntu 16.04) 30 2 * * * root bash /mnt/array0/porch/process.sh

    – Minty
    4 hours ago













  • @Minty OP said "run [...] every hour", so that line is OK. The user crontab edited using crontab -e doesn't require a username (those commands run as your user). The username is required in system crontab files (/etc/cronatb, /etc/cron.d/*).

    – Olorin
    3 hours ago














  • 1





    Was your system, by chance, suspended/hibernated/off or simply logged off during the periods that the cronjobs did not run?

    – user535733
    7 hours ago











  • @user535733, yes, but not always. There were plenty of times when it should have run when it was online but didn't. I don't think this was a factor, but thank you for jumping in.

    – Robert Baker
    7 hours ago











  • wouldn't 1 * * * * mean the first minute of every hour? Remember, the notation is MM HH, not HH MM. Some versions of cron also require a username such as 00 01 * * * root /home/robert/scripts/parking-project.py. My server performs a bulk processing of security footage with a crontab, and it looks like this (ubuntu 16.04) 30 2 * * * root bash /mnt/array0/porch/process.sh

    – Minty
    4 hours ago













  • @Minty OP said "run [...] every hour", so that line is OK. The user crontab edited using crontab -e doesn't require a username (those commands run as your user). The username is required in system crontab files (/etc/cronatb, /etc/cron.d/*).

    – Olorin
    3 hours ago








1




1





Was your system, by chance, suspended/hibernated/off or simply logged off during the periods that the cronjobs did not run?

– user535733
7 hours ago





Was your system, by chance, suspended/hibernated/off or simply logged off during the periods that the cronjobs did not run?

– user535733
7 hours ago













@user535733, yes, but not always. There were plenty of times when it should have run when it was online but didn't. I don't think this was a factor, but thank you for jumping in.

– Robert Baker
7 hours ago





@user535733, yes, but not always. There were plenty of times when it should have run when it was online but didn't. I don't think this was a factor, but thank you for jumping in.

– Robert Baker
7 hours ago













wouldn't 1 * * * * mean the first minute of every hour? Remember, the notation is MM HH, not HH MM. Some versions of cron also require a username such as 00 01 * * * root /home/robert/scripts/parking-project.py. My server performs a bulk processing of security footage with a crontab, and it looks like this (ubuntu 16.04) 30 2 * * * root bash /mnt/array0/porch/process.sh

– Minty
4 hours ago







wouldn't 1 * * * * mean the first minute of every hour? Remember, the notation is MM HH, not HH MM. Some versions of cron also require a username such as 00 01 * * * root /home/robert/scripts/parking-project.py. My server performs a bulk processing of security footage with a crontab, and it looks like this (ubuntu 16.04) 30 2 * * * root bash /mnt/array0/porch/process.sh

– Minty
4 hours ago















@Minty OP said "run [...] every hour", so that line is OK. The user crontab edited using crontab -e doesn't require a username (those commands run as your user). The username is required in system crontab files (/etc/cronatb, /etc/cron.d/*).

– Olorin
3 hours ago





@Minty OP said "run [...] every hour", so that line is OK. The user crontab edited using crontab -e doesn't require a username (those commands run as your user). The username is required in system crontab files (/etc/cronatb, /etc/cron.d/*).

– Olorin
3 hours ago










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