Crontab to Restart Magic Mirror does not work

Desert Rat

I have researched all of the documentation I can find but have failed to resolve this problem.
I can create a Crontab entry as follows 44 * * * * PM2 restart MagicMirror

I created a second entry to put a date entry in a file each minute in the same crontab . This one works as expected.

My research has exposed this kind of issue using pm2 and I’ve attempted to implement suggested resolutions. All were ineffective.

Forgive me if I missed a posed solution but would greatly appreciate any assistance.

Thanks

sdetweil

@desert-rat what is in the pm2 log??

pm2 logs --lines=50

what user is the cron entry running as?
typically root…

but the pm2 entry is setup for pi probably

evroom

@desert-rat

I would try pm2 iso PM2.
And even would advise to use the full path, that can be determined using:
which pm2

With Debian it would be /usr/local/bin/pm2

And you can check this log if cron did anything at all:
/var/log/syslog

Or edit /etc/rsyslog.conf and remove comment on the line with cron (around line 63)
Then the dedicated cron log will be in /var/log/cron.log.
After editing, restart with „sudo systemctl restart rsyslog“.

Good luck,

E.J.

sdetweil

@evroom good catch on the uppercase pm2…

@Desert-Rat
everything in Linux is case sensitive

Desert Rat

@sdetweil
Thanks for the quick reply. I changed the crontab. I actually changed it to PM2 START MagicMirror.

The process I used was to , via the terminal, pm2 stop MagicMirror. This worked and MagicMirror was stopped sucessfully.
Crontab was updated as above PM2 START MagicMirror.
It did not start.

Here are the entries from the log file

Nov 27 13:44:01 raspberrypi CRON[3620]: (pi) CMD (SUDO PM2 START MagicMirror)
Nov 27 13:44:01 raspberrypi CRON[3618]: (CRON) info (No MTA installed, discarding output)
Nov 27 13:55:01 raspberrypi CRON[3661]: (root) CMD (sudo pm2 restart MagicMirror)
Nov 27 13:55:04 raspberrypi CRON[3659]: (CRON) info (No MTA installed, discarding output)
Nov 27 14:17:01 raspberrypi CRON[3772]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)

sdetweil

@desert-rat PM2 is not the command

pm2 is the command and start is the parm

all lower case

evroom

@desert-rat

Could you please show the crontab ?

$ crontab -l

To get rid of this:

(CRON) info (No MTA installed, discarding output)

you have to add >/dev/null 2>&1

Try:

44 * * * * /usr/local/bin/pm2 start MagicMirror >/dev/null 2>&1

Desert Rat

Problem resolved! Outstanding.

My thanks to all who responded.

My mission now is to research the provided solution and try to understand why it worked. Clearly the devil is in the details.

Thanks again to all of you

sdetweil

@desert-rat said in Crontab to Restart Magic Mirror does not work:

to understand why it worked.

your crontab entry

44 * * * * PM2 restart MagicMirror

the working crontab entry

44 * * * * /usr/local/bin/pm2 start MagicMirror >/dev/null 2>&1

could be restart as well…

simple, two things

cron runs as root, BUT certain folders are not in the path
so you need to specify the path to the command

 /usr/local/bin/

second the command is pm2, you tried PM2
in linux EVERYTHING is case sensitive

so yours is command not found, cause there is no command named PM2

Desert Rat

@sdetweil Thanks Sam! I clearly need some education. Do you have a favorite set of training documentation for newbies

Desert Rat