一 自动按照日期分割

if ($time_iso8601 ~ "^(\d{4})-(\d{2})-(\d{2})") {
    set $year $1;
    set $month $2;
    set $day $3;
}

access_log /www/logs/access_$year-$month-$day.log;

二 定时任务分割

#!/bin/bash

## 获取昨天的 yyyy-MM-dd
YESTERDAY=$(date -d "yesterday" +%Y-%m-%d)

## 移动文件
mv /www/logs/access.log /www/logs/access_${YESTERDAY}.log

## 向 Nginx 主进程发送 USR1 信号。USR1 信号是重新打开日志文件
kill -USR1 $(cat /usr/local/nginx/logs/nginx.pid)