Convert monolog JSON log to plain output

logstash-monolog-json-to-plain.conf

input {
    file {
        path => "error.log"
        start_position => beginning
        ignore_older => 0
        codec => json
        sincedb_path => "/dev/null"
    }
}

filter {
    date {
        match => [ "[datetime][date]", "YYYY-MM-dd HH:mm:ss.SSSSSS" ]
    }
}

output {
    stdout {
    }
}