nginx的日志配置可以參見《nginx日志配置指令詳解》一文。如果要想以json格式記錄nginx日志以便logstash分析，該如何指定日志格式呢？可以按照下面的格式來實現。

定義nginx日志格式：
代碼如下:
log_format logstash_json '{ "@timestamp": "$time_local", '
                         '"@fields": { '
                         '"remote_addr": "$remote_addr", '
                         '"remote_user": "$remote_user", '
                         '"body_bytes_sent": "$body_bytes_sent", '
                         '"request_time": "$request_time", '
                         '"status": "$status", '
                         '"request": "$request", '
                         '"request_method": "$request_method", '
                         '"http_referrer": "$http_referer", '
                         '"body_bytes_sent":"$body_bytes_sent", '
                         '"http_x_forwarded_for": "$http_x_forwarded_for", '
                         '"http_user_agent": "$http_user_agent" } }';

指定記錄日志格式：
代碼如下:
access_log  /data/logs/nginx/www.49028c.com.access.log  logstash_json;

日志輸出如下：

不利于閱讀。復制到http://jsonlint.com/美化下格式。