How to pass log output to curl for selfhosted healthchecks.io ping from cron?

[hugalafutro]

Hi,
I am trying to pass log output via curl to a selfhosted healthchecks.io instance as described in healthchecks/healthchecks#719 and running into an issue where it works when I run the script manually, but does not pass the log when running from cron entry.

Any idea how could I make it work?

All the relevant details are in the link above as I first thought it's issue with healthchecks, but testing with different application than raspiBackup worked. For brevity's sake I'll paste the most relevant parts below:

procedure to pass the logs via curl described: https://healthchecks.io/docs/attaching_logs/
root cron entry: 11 5 * * 6 bash /home/pi/myraspibkp.sh 2>&1
script:

#!/bin/bash
curl -fsS --retry 3 https://[REDACTED]/ping/[REDACTED]/start
m=$(/usr/local/bin/raspiBackup)
curl -fsS --retry 3 -m10 --data-raw "$m" https://[REDACTED]/ping/[REDACTED]/$?

if I replace the m variable like so m=$(/usr/games/cowsay hello) and change the cron entry to run every minute for testing I get the cow saying hello correctly.

Thanks for any insights!

[framps]

If raspiBackup detects it's running in the background there is no output to stdout written. Everything you see on the screen when raspiBackup is called in the forground is written into a message file only.

That's the way you get the messages written by raspiBackup when you call raspiBackup in the background: Use option -L to define the log- and messagefile directory and pass the messagefile in the curl call. Messagefile filename is raspiBackup.msg

Hope this helps 😉

[hugalafutro]

Oh I see that's why. So assuming I understand correctly this modification of the script should work:

#!/bin/bash
curl -fsS --retry 3 https://[REDACTED]/ping/[REDACTED]/start
/usr/local/bin/raspiBackup -L /tmp/raspiBackup
m=$(cat /tmp/raspiBackup.msg)
curl -fsS --retry 3 -m10 --data-raw "$m" https://[REDACTED]/ping/[REDACTED]/$?

[framps]

Yes. That will work. Please note: It's option -L, not -F. I updated my answer above accordingly.

[framps]

Just check https://www.linux-tips-and-tricks.de/en/backup#parm_L

[hugalafutro]

Thanks, updated the script snippet above to working version I just tested.