How can update logstash field value?

[abu.sayeed]

Logstash field:

"keywords" => [
     [0] "Audit Success"
 ]

I wish:
"keywords" => "Audit Success"

[magnusbaeck (Magnus Bäck)]

How was this field created? Showing your current configuration is probably helpful.

[abu.sayeed]

filter {
if [type] == "wineventlog" {

ruby {
code => "
  event.get('event_data').each {|k, v|
    event.set(k, v)
  }
  event.remove('event_data')
"
}

mutate {
  rename => [ "[host][name]", "hostname" ]
  rename => [ "[user][identifier]", "user_identifier" ]
  rename => [ "[user][type]", "user_type" ]
  rename => [ "[user][domain]", "user_domain" ]
  rename => [ "[user][name]", "user.name" ]
}
mutate {
   remove_field => [ "tags", "opcode", "@version", "beat", "message", "LogonGuid", "ProcessId", "ProcessName", "SubjectLogonId", "SubjectUserSid", "TargetInfo", "TargetLogonGuid", "activity_id", "event_id", "opcode", "process_id", "provider_guid", "record_number", "param10", "param11", "param2", "param4", "param5", "param8", "thread_id", "param7", "LmPackageName", "PrivilegeList", "IpPort", "ImpersonationLevel", "KeyLength", "TransmittedServices", "TargetLogonId", "TargetUserSid", "host" ]
   }
  }
 }




  available fields like:
  "keywords" => [
        [0] "Download",
        [1] "Started"
        ],

   I wish:
   keywords_Download => 0
   keywords_Download_started => 1

     How can split those fields?
    Thank You.

[magnusbaeck (Magnus Bäck)]

Okay. And keywords is initially [event_data][keywords]? Changing event.set(k, v) to event.set(k, v[0]) will extract the first element of the array, but it assumes that all values in event_data are arrays which might not be true. You can use a conditional to check the type of v and only access the first array element if v actually is an array.