Attaching Logs

Cron monitoring ping endpoints accept HTTP HEAD, GET and POST request methods.

When using HTTP POST, you can include arbitrary payload in the request body. If the request body looks like a UTF-8 string, Cron monitoring will log the first 10 kilobytes of the request body, so you can inspect it later.

Logging Command Output

In this example, we run certbot renew, capture its output, and submit the captured output to Cron monitoring:


m=$(/usr/bin/certbot renew 2>&1)
curl -fsS --retry 3 -X POST --data-raw "$m"

In Combination with the /fail Endpoint

We can extend the previous example and signal either success or failure depending on the exit code:



m=$(/usr/bin/certbot renew 2>&1)

if [ $? -ne 0 ]; then url=$url/fail; fi
curl -fsS --retry 3 -X POST --data-raw "$m" $url

All in One Line

Finally, all of the above can be packaged in a single line. The one-line version can be put directly in crontab, without using a wrapper script.

m=$(/usr/bin/certbot renew 2>&1); curl -fsS -X POST --data-raw "$m" "$([ $? -ne 0 ] && echo -n /fail)"