How do I write to the log?

robbie · January 13, 2022, 1:29am

I feel stupid for even asking, but how can I get my API code to write debug logs? The docs here are remarkably obtuse.

https://docs.nextcloud.com/server/latest/developer_manual/basics/logging.html?highlight=logging

gas85 · January 13, 2022, 7:46am

Yeah, a bit of reverse engineering needed. Basically it is JSON, but with few mandatory fields, e.g. example from preview generator:

github.com

GAS85/nextcloud_scripts/blob/master/nextcloud-preview.sh#L98

    
      
          	CronLogFile=/dev/null
          fi
          
          
touch $LOCKFILE
          
          
reqId=$(< /dev/urandom tr -dc A-Za-z0-9 | head -c20)
          
          
messageToLog () {
          
          
	# ${0##*/} from https://stackoverflow.com/questions/192319/how-do-i-know-the-script-file-name-in-a-bash-script
          	echo \{\"reqId\":\"$reqId\",\"user\":\"none\",\"app\":\"${0##*/}\",\"url\":\"$Command $OPTIONS\",\"message\":\"$Message\",\"level\":$LvL,\"time\":\"`date "+%Y-%m-%dT%H:%M:%S%:z"`\"\} >> $LogFile
          
          
}
          
          
Message="+++ Starting Cron Preview generation +++"
          messageToLog
          date >> $CronLogFile
          
          
$PHP $Command $OPTIONS $DEBUG >> $CronLogFile
          
          
duration=$SECONDS

Where

reqid is some random unique string for the transaction, e.g. reqId=$(< /dev/urandom tr -dc A-Za-z0-9 | head -c20)
user is user, or none if script executed globally
app is an application name that works
url basically is the message body and here you can put whatever output you need
level in your case could be debug
time is a timestamp in standard +%Y-%m-%dT%H:%M:%S%:z or customized in config.php format.

UPDATE:

Sorry, I see that you asked from the PHP api…

robbie · January 13, 2022, 2:41pm

Hah yes, in the PHP code. I was trying to add some debugging to the REST API controller, but can’t figure out how to get access to the $logger. I made do with throwing an exception, but that’s going to make debugging harder.