logstash timestamp test

lstestdate.conf

input { 
  generator {
    message => "2020-02-10T15:14:15.003Z"
    count => 1
  }
}

filter {

  ruby {
    code => "
      event.set('s_time', Time.now)
#      sleep(1)
#      event.set('e_time', Time.now)
    "
  }

  mutate {
    add_field => { "timestamp_logstash_add_field" => "%{@timestamp}" }
  }

  ruby {
    code => "event.set('timestamp_logstash_ruby',event.get('@timestamp'))"
  }

 
  grok {
    match => { "message" => "%{TIMESTAMP_ISO8601:timestamp_source}" }
  }

  date {
    match => [ "timestamp_source", "ISO8601" ]
  }
 
  ruby {
    code => "event.set('time_elapsed_ruby',event.get('timestamp_logstash_ruby') - event.get('@timestamp'))"
  }

}

output { stdout { codec => rubydebug } }