nginx日志按照天进行分割

直接在nginx配置文件中，配置日志循环，而不需使用logrotate或配置cron任务。需要使用到$time_iso8601 内嵌变量来获取时间。$time_iso8601格式如下：2015-08-07T18:12:02+02:00。然后使用正则表达式来获取所需时间的数据。

按天分割日志

使用下面的代码块

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

access_log /data/logs/nginx/www.ttlsa.com-$year-$month-$day-access.log;

也可以使用Perl语法来捕获，如下：

if ($time_iso8601 ~ "^(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})") {}

access_log /data/logs/nginx/www.ttlsa.com-$year-$month-$day-access.log;

按时、分、秒分割

if ($time_iso8601 ~ "^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})")
{
set $year $1;
set $month $2;
set $day $3;
set $hour $4;
set $minutes $5;
set $seconds $6;
}

非常方便的进行日志分割。建议按小时分割日志，方便分析查询日志。

例子：

server {
listen       80;
server_name  www.test.com;
if ($time_iso8601 ~ "^(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})") {}
access_log /var/log/nginx/www.test.com-$year-$month-$day-access.log;
location / {
root   html;
index  index.html index.htm;
}
}

参考：http://www.ttlsa.com/nginx/nginx-configure-file-log-rotation/