Use Ruby to get field string length

Elastic Stack Logstash
1

I am trying to get the string length of a dns domain name and place into a new field. I've seen several posts to use ruby to achieve this but I can't seem to get it to work. This code is placed inside the filter {} brackets. I've also tried variations where the single quotes are around all the '[dns][domain][name]' blocks. I'm getting a _rubyexecption in the tags.

ruby {
  code => "event['dns']['domain']['name']['size']  = event['dns']['domain']['name'].length"
 }
2

Use this

ruby {
  code => "event.set('[dns][domain][size]', event.get('[dns][domain][name]').length)"
 }
3

That did it! Thanks for the help and perhaps the fastest response I've ever seen on this site!!