Nginx logging in JSON format

etc-nginx-nginx.conf

# /etc/nginx/nginx.conf 

log_format main '{'
                 '"remote_addr": "$remote_addr",'
                 '"remote_user": "$remote_user",'
                 '"time_local":  "$time_local",'
                 '"request":     "$request",'
                 '"status":      "$status",'
                 '"body_bytes_sent": "$body_bytes_sent",'
                 '"http_referer": "$http_referer",' 
                 '"http_user_agent": "$http_user_agent"'
                 '}';