Logstash Filter Json To Array of Json

Elastic Stack Logstash
6

OK. You could do it using json_encode (which you will need to install). First copy all the interesting fields to another field, which we can put in [@metadata]

    mutate { remove_field => [ "@timestamp", "@version", "host", "message", "sequence" ] }
    ruby {
        code => '
            event.to_hash.each { |k,v|
                event.set("[@metadata][fields][#{k}]", v)
            }
        '
    }

Then encode it into another field, which again can be in [@metadata]

    json_encode { source => "[@metadata][fields]" target => "[@metadata][string]" }

and output it using a plain codec

output { stdout { codec => plain { format => "[ %{[@metadata][string]} ]
" } } }

Note that you use a literal newline in the format string to tell it to append a newline to the output.