nginx/tengine服务器重启 /“var/run/nginx/nginx.pid" no such file or directory问题

环境 Centos7

问题描述：在重启虚拟机后，会删除/var/run下的文件。会杀掉进程，导致重新启动后nginx服务器无法启动。

# systemctl status nginx
>>> 
● nginx.service - SYSV: nginx is a World Wide Web server. It is used to servea
   Loaded: loaded (/etc/rc.d/init.d/nginx; bad; vendor preset: disabled)
   Active: active (exited) (Result: exit-code) since 二 2018-01-30 14:48:43 CST; 10min ago
     Docs: man:systemd-sysv-generator(8)
  Process: 2672 ExecReload=/etc/rc.d/init.d/nginx reload (code=exited, status=7)
  Process: 1114 ExecStart=/etc/rc.d/init.d/nginx start (code=exited, status=0/SUCCESS)

1月 30 14:48:43 bogon systemd[1]: Starting SYSV: nginx is a World Wide Web server. It is used to servea...
1月 30 14:48:43 bogon nginx[1114]: Starting nginx: [  确定  ]
1月 30 14:48:43 bogon systemd[1]: Started SYSV: nginx is a World Wide Web server. It is used to servea.
1月 30 14:48:44 bogon nginx[1114]: nginx: [emerg] open() "/var/run/nginx/nginx.pid" failed (2: No such file or directory)
1月 30 14:50:32 bogon systemd[1]: nginx.service: control process exited, code=exited status=7
1月 30 14:50:32 bogon systemd[1]: Reload failed for SYSV: nginx is a World Wide Web server. It is used to servea.
1月 30 14:56:01 bogon systemd[1]: nginx.service: control process exited, code=exited status=7
1月 30 14:56:01 bogon systemd[1]: Reload failed for SYSV: nginx is a World Wide Web server. It is used to servea.

问题解决思路：

• 配置文件中指定nginx进程文件，nginx.pid是nginx的进程文件，文件中一般只会写一个进程的编号。所以我们先查看配置文件中的进程文件的地址。查看 安装目录下的/conf/nginx.conf 在这里我的是 /opt/stx/soft/tengine2.2.0/conf/nginx.conf

#user  nobody;
worker_processes  1;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;
#error_log  "pipe:rollback logs/error_log interval=1d baknum=7 maxsize=2G";

pid        logs/nginx.pid;

nginx的进程目录在logs/nginx.pid 如果这行被注释，则pid文件在 /var/run/nginx 如果没有这个目录则创建这个目录

mkdir -p /var/run/nginx

• 我们在重新运行nginx的时候需要去告诉运行环境去加载nginx的进程配置。所以需要指定配置文件
  在我的环境中：

/opt/stx/soft/tengine2.2.0/sbin/nginx -c /opt/stx/opt/tengine2.2.0/conf/nginx.conf

执行后，再次查看会发现刚才指定的目录下有了nginx.pid文件。然后重启nginx就恢复正常了

systemctl reload nginx