I am quite new to nitrous and programming in general. However, I wanted to see why my crontab job isn't doing anything on Nitrous.io.
I am using a virtualenv and I am in the understanding that you can run them on crontab. THis is my cronline:
10 6,19 * * * /home/action/susteq/bin/activate /home/action/susteq/start.py 2>&1 >> /home/action/susteq/log/start.log
Crontab should work on Nitrous.IO as long as you are actively logged into the box (or using tmux) and the box doesn't shutdown from inactivity. Paid boxes will stay running indefinitely.
Looking at this command you may want to ensure it runs as expected outside of the crontab. Try running the process first:
$ /home/action/susteq/bin/activate /home/action/susteq/http://start.py 2>&1 >> /home/action/susteq/log/start.log
If not then you may actually want to try placing 2>%1 at the end of the line (further explained on this redirection tutorial). The following command may be what you are looking for:
$ /home/action/susteq/bin/activate /home/action/susteq/start.py >> /home/action/susteq/log/start.log 2>&1
If that works, try adding it to your crontab:
$ 10 6,19 * * * /home/action/susteq/bin/activate /home/action/susteq/start.py >> /home/action/susteq/log/start.log 2>&1
Update: To run cron on Nitrous Pro you need to enable privileged mode on your container, which requires that you enable advanced container management. More details can be found here:
https://community.nitrous.io/docs/running-cron-on-nitrous
Related
I have a discord bot running on a raspberry pi that i need to restart every day, I'm trying to do this through crontab but with no luck.
It manages to kill the active screen processes but never starts an instance, not that I can see with "screen -ls" and I can tell that it doesn't create one that I can't see as the bot itself does not come online.
Here is the script:
#!/bin/bash
sudo pkill screen
sleep 2
screen -dmS discordBot
sleep 2
screen -S "discordBot" -X stuff "node discordBot/NEWNEWNEWN\n"
Here is also the crontab:
0 0 * * * /bin/bash /home/admin/discordBot/script.sh
Is it possible to have crontab run a screen session? And if so how?
Previously I tried putting the screen command stright into cron but now I have it in a bash script instead.
If I run the script in the terminal it works perfectly, it’s just cron where it fails. Also replacing "screen" with the full path "/usr/bin/screen" does not change anything.
So the best way of doing it, without investigating the underlying problem would be to create a systemd service and putting a restart command into cron.
/etc/systemd/system/mydiscordbot.service:
[Unit]
Description=A very simple discord bot
[Service]
Type=simple
ExecStart=node /path/to/my/discordBot.js
[Install]
WantedBy=multi-user.target
Now you can run your bot with systemctl start mydiscordbot and can view your logs with journalctl --follow -u mydiscord bot
Now you only need to put
45 2 * * * systemctl restart discordbot
into root's crontab and you should be good to go.
You probably should also write the logs into a logfile, maybe /var/log/mydiscordbot.log, but how and if you do that is up to you.
OLD/WRONG ANSWER:
cron is run with a minimal environment, and depending on your os, /usr/bin/ is probably not in the $PATH var. screen is mostlikely located at /usr/bin/screen, so cron can't run it because it can't find the screen binary. try replacing screen in your script with /usr/bin/screen
But the other question here is: Why does your discord bot need to be restarted every day. I run multiple bots with 100k+ users, and they don't need to be restarted at all. Maybe you should open a new question with the error and some code snippets.
I don't know what os your rpi is running, but I had a similar issue earlier today trying to get vms on a server to launch a terminal and run a python script with crontab. I found a very easily solution to automatically restart it on crashes, and to run something simply in the background. Don't rely on crontab or an init service. If your rpi as an x server running, or anything that can be launched on session start, there is a simple shell solution. Make a bash script like
while :; do
/my/script/to/keep/running/here -foo -bar -baz >> /var/log/myscriptlog 2>&1
done
and then you would start it on .xprofile or some similar startup operation like
/path/to/launcher.sh &
to have it run the background. It will restart automatically everytime it closes if started in something like .xprofile, .xinitrc, or anything ran at startup.
Then maybe make a cronjob to restart the raspberry pi or whatever system is running the script but this script wil restart the service whenever it's closed anyway. Maybe you can put that cronjob on a script but I don't think it would launch the GUI.
Some other things you can do to launch a GUI terminal in my research with cronjob that you can try, though they didn't work for my situation on these custom linux vms, and that I read was a security risk to do this from a cronjob, is you can specify the display.
* * * * * DISPLAY=:0 /your/gui/stuff/here
but you would would need to make sure the user has the right permissions and it's considered an unsafe hack to even do this as far as I have read.
for my issue, I had to launch a terminal that stayed open, and then changed to the directory of a python script and ran the script, so that the local files in directory would be called in the python script. here is a rough example of the "launcher.sh" I called from the startup method this strange linux distro used lol.
#!/bin/sh
while :; do
/usr/bin/urxvt -e /bin/bash -c "cd /path/to/project && python loader.py"
done
Also check this source for process management
https://mywiki.wooledge.org/ProcessManagement
I'm trying to run only one instance of my back up script as a cron job.
I know I can do it with a function that checks if the process is running:
if pgrep -x rclone >/dev/null
then
# rclone is still running, backup is not done yet, exit.
exit
else
# rclone is not running.
# start backup.
/path/to/rclone/script.sh
fi
But after some research, I found out flock should be used instead of looking for process ID, in crontab -e, in this case, run the script every 30 minutes:
*/30 * * * * /usr/bin/flock -n /var/lock/myjob.lock /path/to/rclone/script.sh
Running the command above requires sudo. Therefore, the script asks for sudo password, and never runs. (I ran the command above manually, that's how I found out).
How exactly do I use flock? Do I type a variable in my script that injects the sudo password when flock asks for it? (I know it's not secure, so there must be a different way to do this).
I tried to research this subject but couldn't find any good answers that explain how to use it properly.
Thank you.
I am new to setting up cronjobs and I'm trying to do it on a virtual machine in google compute engine. After a bit of research, I found this StackOverflow question: Running Python script at Regular intervals using Cron in Virtual Machine (Google Cloud Platform)
As per the answer, I managed to enter the crontab -e edit mode and set up a test cronjob like 10 8 * * * /usr/bin/python /scripts/kite-data-pull/dataPull.py. I also checked the system time, which was in UTC, and entered the time according to that.
The step I'm supposed to take, as per the answer, is to run sudo systemctl restart cron which is throwing an error for me:
sudo systemctl restart cron
System has not been booted with systemd as init system (PID 1). Can't operate.
Failed to connect to bus: Host is down
Any suggestions on what I can do to set up this cronjob correctly?
Edit a cron jobs with crontab -e and inset a line:
* * * * * echo test123 > /your_homedir_path/file.log
That will write test123 every minute into file.log file.
Then do tail if and wait a couple minutes. You should see test123 lines appearing in the file (and screen).
If it runs try running your python file but first make your .py file executable with "chmod +x script.py"
Here you can find my reply to similar question.
I have made the following cronjob sh file :
Vi RestartServices.sh
/etc/init.d/b1s stop
sleep 10
/etc/init.d/sapb1servertools stop
sleep 10
sudo -u ndbadm /usr/sap/NDB/HDB00/HDB stop
sleep 20
sudo -u ndbadm /usr/sap/NDB/HDB00/HDB start
sleep 10
/etc/init.d/sapb1servertools start
sleep 10
/etc/init.d/b1s start
When I run this file manually the job runs correctly.
When scheduled in crontab (root user)
Crontab content:
# srvmagtCron: restarts daemons that died
0,5,10,15,20,25,30,35,40,45,50,55 * * * * /bin/sh -c "[ -x /etc/srvmagt/srvmagtCron ] && /etc/srvmagt/srvmagtCron"
0 2 * * * /hanamnt/shared/NDB/HDB00/backup/scripts/VGRbackup.sh
#RESTARTS SERVICE LAYER , SAPB1ServerTools service , HDB
0 3 * * * /hanamnt/shared/NDB/HDB00/backup/scripts/RestartServices.sh
It does get started at the requested time but I think it failed to execute the sudo line as the HDB service has not been restarted.
I'm trying to find out why?
Is it because sudo cannot be executed in a cronjob?
(service needs to start using user ndbadm)
path:
/opt/sap/sapjvm_6//bin:/opt/fujitsu/bwai/bin:/sbin:/usr/sbin:/usr/local/sbin:/root/bin:/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/X11R6/bin:/usr/games:/usr/lib64/jvm/jre/bin:/usr/lib/mit/bin:/usr/lib/mit/sbin
You have a non-standard $PATH and crond(8) is running your crontab(5) entries with a shorter $PATH. See also environ(7), credentials(7) and execvp(3) with execve(2)
My recommendation would be to write a complete shell script, and put only that in crontab. So don't use sh -c in crontab entries, and set explicitly the PATH (either, and preferably, in the shell scripts your crontab entry is firing, or maybe in your crontab file).
You could for example have
0,5,10,15,20,25,30,35,40,45,50,55 * * * * /hanamnt/shared/srvmagt.sh
in your crontab, and have an executable /hanamnt/shared/srvmagt.sh file starting with
#!/bin/bash
export PATH=/opt/sap/sapjvm_6//bin:/opt/fujitsu/bwai/bin:/sbin:\
/usr/sbin:/usr/local/sbin:/root/bin:/usr/local/bin:\
/usr/bin:/bin:/usr/bin/X11:/usr/X11R6/bin:/usr/games:\
/usr/lib64/jvm/jre/bin:/usr/lib/mit/bin:/usr/lib/mit/sbin
# log a starting message
logger start of $0
Notice the use of logger(1) - and you should use it more wisely to get appropriate log messages under /var/log
BTW, your PATH is ridiculously too long. Such a long PATH is messy (and might slow down your shells) and could be a security risk; my recommendation would be to have a much shorter one (perhaps as short as $HOME/bin:/usr/local/bin:/bin:/usr/bin) and add appropriate symlinks or scripts in e.g. $HOME/bin/ or /usr/local/bin/ using explicit program paths.
Notice that sudo could be used in a crontab job (but that is often unwise) and then probably should be configured in /etc/sudoers ; perhaps you should prefer /bin/su (see su(1)...) in some shell script.
Read also more about setuid. Sometimes it is wiser to write in C a wrapper setuid- program using it (with setreuid(2)), but be careful (you could open huge security holes by mistake).
Read also Advanced Linux Programming (freely downloadable, a bit old) then syscalls(2) to understand better how Linux works internally. You need to have a better and more clear picture of your system in your head.
I'm using a basic shell script to log the results of top, netstat, ps and free every minute.
This is the script:
/scripts/logtop:
TERM=vt100
export TERM
time=$(date)
min=${time:14:2}
top -b -n 1 > /var/log/systemCheckLogs/$min
netstat -an >> /var/log/systemCheckLogs/$min
ps aux >> /var/log/systemCheckLogs/$min
free >> /var/log/systemCheckLogs/$min
echo "Message Content: $min" | mail -s "Ran System Check script" email#domain.com
exit 0
When I run this script directly it works fine. It creates the files and puts them in /var/log/systemCheckLogs/ and then sends me an email.
I can't, however, get it to work when trying to get cron to do it every minute.
I tried putting it in /var/spool/cron/root like so:
* * * * * /scripts/logtop > /dev/null 2>&1
and it never executes
I also tried putting it in /var/spool/cron/myservername and also like so:
* * * * * /scripts/logtop > /dev/null 2>&1
it'll run every minute, but nothing gets created in systemCheckLogs.
Is there a reason it works when I run it but not when cron runs it?
Also, here's what the permissions look like:
-rwxrwxrwx 1 root root 326 Jul 21 01:53 logtop
drwxr-xr-x 2 root root 4096 Jul 21 01:51 systemCheckLogs
Normally crontabs are kept in "/var/spool/cron/crontabs/". Also, normally, you update it with the crontab command as this HUPs crond after you're done and it'll make sure the file gets in the correct place.
Are you using the crontab command to create the cron entry? crontab to import a file directly. crontab -e to edit the current crontab with $EDITOR.
All jobs run by cron need the interpreter listed at the top, so cron knows how to run them.
I can't tell if you just omitted that line or if it is not in your script.
For example,
#!/bin/bash
echo "Test cron jon"
When running from /var/spool/cron/root, it may be failing because cron is not configured to run for root. On linux, root cron jobs are typically run from /etc/crontab rather than from /var/spool/cron.
When running from /var/spool/cron/myservername, you probably have a permissions problem. Don't redirect the error to /dev/null -- capture them and examine.
Something else to be aware of, cron doesn't initialize the full run environment, which can sometimes mean you can run it just fine from a fully logged-in shell, but it doesn't behave the same from cron.
In the case of above, you don't have a "#!/bin/shell" up top in your script. If root is configured to use something like a regular bourne shell or cshell, the syntax you use to populate your variables will not work. This would explain why it would run, but not populate your files. So if you need it to be ksh, "#!/bin/ksh". It's generally best not to trust the environment to keep these things sane. If you need your profile run the do a ". ~/.profile" up front as well. Or a quick and dirty way to get your relatively full env is to do it from su as such "* * * * * su - root -c "/path/to/script" > /dev/null 2>&1
Just some things I've picked up over the years. You're definitely expecting a ksh based on your syntax, so you might want to be sure it's using it.
Thanks for the tips... used a little bit of each answer to get to the bottom of this.
I did have the interpreter at the top (wasn't shown here), but may have been wrong.
Am using #!/bin/bash now and that works.
Also had to tinker with the permissions of the directory the log files are being dumped in to get things working.