Remove everything up to ->

Elastic Stack Logstash
1

Hi all,

I have a log that is created from various different source servers. Using Wazuh, each item is forwarded to this one log which is then intended to go off to a remote QRADAR server.

Wazuh is adding its own part to the log and I've managed to create a conf file that removes everything that logstash and filebeat adds which gets me to this:

{"message":"2022 Aug 05 07:45:43 logServer01->192.22.0.5 Aug 05 2022 07:45:43 FIREWALL01 : %ASA-6-302020: Built inbound ICMP connection for faddr 172.10.123.456/24592 gaddr 172.10.132.456/0 laddr 172.10.123.186/0 type 8 code 0 "}

My problem is that the QRADAR server will still see this log entry as coming from logserver01 and not as though it's coming from 192.22.0.5 ie Firewall01. If I could delete everything before and including -> I think I should be on the right path. Could one of you geniuses advise me on how to achieve that please?

My conf file looks like this:


input {
   beats {
        port => "5044"
#       type => "log"
        }
}
filter {

   date {
      match => [ 'syslog_timestamp', 'ISO8601' ]
      remove_field => [ 'syslog_timestamp' ]
    }
   mutate {
       remove_field => [ "log.level", "@timestamp", "log.logger", "ecs", "log", "path", "tags", "@version", "input", "agent", "type", "name", "event", $

     }
#      if [type] == "syslog" {
#        grok {
#          match => { "message" => "%{TIMESTAMP_ISO8601:timestamp} %{LOGLEVEL:log-level} \[%{DATA:class}\]:%{GREEDYDATA:message}" }
# }
#      }
}



output {
        file {
         path => "/tmp/testfile.log"
        }
}
2

You could use a dissect filter.

dissect {
    mapping => {
        "message" => "%{}->%{message}"
    }
}

It will ignore everything that is before the -> and store everything that is after in the message field, overriding the original message field.

1 Like
3

Many thanks. It works a treat.

4

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