Question on kv filter

[moberreiter (Markus Oberreiter)]

Hello everyone!

I have a log from syslog which logstash should parse:

Source:

Jan 3 10:14:40 123.123.123.123 {"zone_src":"SRC","zone_dst":"DST","reason":"rule","rule_id":12345,"rule_description":"Rule Description","action":"ACCEPT","@timestamp":"2023-01-03T10:14:39.151179+0100","timestamp":1672737279,"timestamp_usec":151179,"iface_in":"123456","iface_out":"asdf1.123","ip_src":"100.100.100.100","ip_dst":"200.200.200.200","protocol":6,"port_src":12345,"port_dst":1234,"mark":352321536,"tos":0,"host_id":123456,"host_name":"hostname123,"logtype":"forward"}

Now I want kv to split the keys and values within the curly brackets and exclude the date and IP Address before the curly brackets.

I tried it with the following config but it won't work:

input {
 file {
   path => ["/var/log/syslog-test4"]
   sincedb_path => "/dev/null"
   start_position => "beginning"
      }
}
filter {
 dissect {
   mapping => {
"message" => "\"%{month1} %{day2} %{time3} %{host4} {\"zone_src\":\"%{zone_src}\",\"zone_dst\":\"%{zone_dst}\",\"reason\":\"%{reason}\",\"rule_id\":%{rule_id},\"rule_description\":\"%{rule_description}\",\"action\":\"%{action}\",\"@timestamp\":\"%{@timestamp}\",\"timestamp\":%{timestamp},\"timestamp_usec\":%{timestamp_usec},\"iface_in\":\"%{iface_in}\",\"iface_out\":\"%{iface_out}\",\"ip_src\":\"%{ip_src}\",\"ip_dst\":\"%{ip_dst}\",\"protocol\":%{protocol},\"port_src\":%{port_src},\"port_dst\":%{port_dst},\"mark\":%{mark},\"tos\":%{tos},\"host_id\":%{host_id},\"host_name\":\"%{host_name}\",\"logtype\":\"%{logtype}\"}\""

}
   remove_field => ["month1" , "day2" , "time3" , "host4"]
  }

        kv {
           source => "message"
           field_split => ","
           value_split => ":"
           trim_key => "{\\\""
           trim_value => "\\\"}"
           #target_field => "details"
           include_brackets => false
    }
}

Can anyone of you assist on how I could achieve this?

Thank you,

Max

[leandrojmp (Leandro Pereira)]

That part of your log is not a KV, it is a JSON, you should use the json filter.

Change your dissect to this:

dissect {
    mapping => {
        "message" => "%{month1} %{day2} %{time3} %{%host4} %{jsonMessage}"
    }
}

Then use a json filter with the jsonMessage field.

json {
    source => "jsonMessage"
}