How to get json message to logstash without extracting fields from fluentd

[alwalaupendra]

we are sending json message from application server to logstash by using fluentd. In logstash without using any json filter the fields are extracted and showing in kibana. I am suspecting the fields are extracted from fluentd itself. But i want extract the fields from logstash not fluetnd. Could please guide me how can i get json message without extracting fields from fluentd. I am sharing fluentd config below

@type tail path /opt/jenkins/deploymentlogs/output.json pos_file /var/log/td-agent/httpd-access.log.pos #format json time_format %Y-%m-%dT%H:%M:%S tag test read_from_head true #exclude_path ["/var/log/fluent*"] #from_encoding UTF-8 #encoding UTF-8 # # @type json # @type multi_format format json time_key time keep_time_key true time_format %Y-%m-%dT%H:%M:%S.%NZ @type grep key message pattern /force flushing buffer events/ @type grep key message pattern /flushing all buffer forcedly/