How to aggregate a value repeatedly

[magdieldominguez (magdiel)]

Hi I have a log file and in each line it contains a number that I need to keep adding to get the total produced per log.

So some of the lines in the log file could be...
10.05.17 20:06:39.79 UPDATE/Add: Legs:15
10.05.17 20:06:39.79 UPDATE/Add: Legs:30

I want to add up the number after Legs to be able to get a total of 45 but im having a hard time doing that. Help would be greatly appreciated. I am using the aggregate filter but not sure how to use it in this case.

my config file looks something like this.

input {
   file {
         path => "C:\Logstash\logstash-5.6.1\ExampleLogs\legs.log"
         type => "legs"
         start_position => "beginning"
        }
  }
   filter{
   if [type] == "legs" {
 	  grok {
 	  match => ["message", "(?<OriginalLogTime>%{MONTHNUM}.%{MONTHDAY}.%{YEAR} %{TIME})%{SPACE}(?<legCount>%{DATA:StatusEvent}:%{SPACE}Legs:?%{SPACE}%{BASE16NUM:theLegs})%{GREEDYDATA:message}"]
 	  }
   
 	  mutate {
       convert => { "theLegs" => "integer" }
       }
 
       aggregate {
        task_id => "%{P.23.P24.ABK}"
        code => "map['total_legs'] ||= 0 ; map['total_legs'] += event.get('theLegs')"
        push_map_as_event_on_timeout => true
       }
   }

  }
 output {
   if [type] == "legs" {
     elasticsearch {
       index => "legsloaded"
       hosts => "localhost:9200"
     } 
   }

I know the filter is a little confusing but it does work. I check Kibana but there is no total_legs field created not sure what I am doing wrong.

thank you!