log_format log_json '{ "@timestamp": "$time_local", '
'"N_remote_addr": "$remote_addr", '
'"N_referer": "$http_referer", '
'"N_request": "$request", '
'"N_status": $status, '
'"N_bytes": $body_bytes_sent, '
'"N_agent": "$http_user_agent", '
'"N_x_forwarded": "$http_x_forwarded_for", '
'"N_up_addr": "$upstream_addr",'
'"N_up_host": "$upstream_http_host",'
'"N_up_resp_time": "$upstream_response_time",'
'"N_request_time": "$request_time"'
' }';