思路

Nginx 官方其实给出了如何滚动日志的说明：
Rotating Log-files
In order to rotate log files, they need to be renamed first. After that USR1 signal should be sent to the master process. The master process will then re-open all currently open log files and assign them an unprivileged user under which the worker processes are running, as an owner. After successful re-opening, the master process closes all open files and sends the message to worker process to ask them to re-open files. Worker processes also open new files and close old files right away. As a result, old files are almost immediately available for post processing, such as compression.
这段说明的大意是：

• 先把旧的日志文件重命名
• 然后给 nginx master 进程发送 USR1 信号
• nginx master 进程收到信号后会做一些处理，然后要求工作者进程重新打开日志文件
• 工作者进程打开新的日志文件并关闭旧的日志文件

其实真正需要我们做的工作只有前面两点！

创建测试环境

假设你的系统中已经安装好了 docker，这里我们直接运行一个 nginx 容器：

$ docker run -d \     -p 80:80 \     -v $(pwd)/logs/nginx:/var/log/nginx \     --restart=always \     --name=mynginx \     nginx:1.11.3

注意，我们把 nginx 的日志绑定挂载到了当前目录下的 logs 目录下。
把下面的内容保存到 test.sh 文件中：

#!/bin/bash  for ((i=1;i<=100000;i++)) do     curl http://localhost > /dev/null    sleep 1done

然后运行这个脚本，就可以模拟产生连续的日志记录。

创建滚动日志的脚本

创建 rotatelog.sh 文件，其内容如下：

#!/bin/bash  getdatestring() {     TZ='Asia/Chongqing' date "+%Y%m%d%H%M" } datestring=$(getdatestring)  mv /var/log/nginx/access.log /var/log/nginx/access.${datestring}.log mv /var/log/nginx/error.log /var/log/nginx/error.${datestring}.log kill -USR1 `cat /var/run/nginx.pid`