使用的是阿里云ECS，操作系统选的centos 7.4，iptables和防火墙已配置80端口，
显示错误/var/run/nginx.pid文件不可读？请帮忙分析解决

[root@iZuf6igcce8m64xznu8cvvZ ~]# nginx -v
nginx version: nginx/1.14.0

[root@iZuf6igcce8m64xznu8cvvZ ~]# systemctl start nginx

[root@iZuf6igcce8m64xznu8cvvZ ~]# systemctl status nginx
● nginx.service - nginx - high performance web server
Loaded: loaded (/usr/lib/systemd/system/nginx.service; enabled; vendor preset: disabled)
Active: active (running) since Thu 2018-06-21 08:28:54 CST; 6s ago

 Docs: http://nginx.org/en/docs/

Process: 26744 ExecStop=/bin/kill -s TERM $MAINPID (code=exited, status=1/FAILURE)
Process: 28132 ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf (code=exited, status=0/SUCCESS)
Main PID: 28133 (nginx)
CGroup: /system.slice/nginx.service

       ├─28133 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
       └─28134 nginx: worker process

Jun 21 08:28:54 iZuf6igcce8m64xznu8cvvZ systemd[1]: Starting nginx - high performance web server...
Jun 21 08:28:54 iZuf6igcce8m64xznu8cvvZ systemd[1]: PID file /var/run/nginx.pid not readable (yet?) after start.
Jun 21 08:28:54 iZuf6igcce8m64xznu8cvvZ systemd[1]: Started nginx - high performance web server.

[root@iZuf6igcce8m64xznu8cvvZ ~]# ps -ef | grep nginx
root 28133 1 0 08:28 ? 00:00:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
hyt_cms 28134 28133 0 08:28 ? 00:00:00 nginx: worker process
root 28142 28108 0 08:33 pts/0 00:00:00 grep --color=auto nginx
[root@iZuf6igcce8m64xznu8cvvZ ~]#

nginx配置文件如下：/etc/nginx/nginx.conf

For more information on configuration, see:

* Official English Documentation: http://nginx.org/en/docs/

* Official Russian Documentation: http://nginx.org/ru/docs/

user hyt_cms hyt_cms;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /var/run/nginx.pid;

pid /usr/local/nginx/nginx.pid;

Load dynamic modules. See /usr/share/nginx/README.dynamic.

include /usr/share/nginx/modules/*.conf;

events {

worker_connections 1024;

}

http {

log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                  '$status $body_bytes_sent "$http_referer" '
                  '"$http_user_agent" "$http_x_forwarded_for"';

access_log  /var/log/nginx/access.log  main;

sendfile            on;
tcp_nopush          on;
tcp_nodelay         on;
keepalive_timeout   65;
types_hash_max_size 2048;

include             /etc/nginx/mime.types;
default_type        application/octet-stream;

# Load modular configuration files from the /etc/nginx/conf.d directory.
# See http://nginx.org/en/docs/ngx_core_module.html#include
# for more information.
include /etc/nginx/conf.d/*.conf;

# server {
#     listen       80 default_server;
#     listen       [::]:80 default_server;
#     server_name  _;
#     root         /usr/share/nginx/html;

    # Load configuration files for the default server block.
#     include /etc/nginx/default.d/*.conf;

#     location / {
#     }

#     error_page 404 /404.html;
#         location = /40x.html {
#     }

#     error_page 500 502 503 504 /50x.html;
#         location = /50x.html {
#     }
# }

Settings for a TLS enabled server.

server {

listen 443 ssl http2 default_server;

listen [::]:443 ssl http2 default_server;

server_name _;

root /usr/share/nginx/html;

ssl_certificate "/etc/pki/nginx/server.crt";

ssl_certificate_key "/etc/pki/nginx/private/server.key";

ssl_session_cache shared:SSL:1m;

ssl_session_timeout 10m;

ssl_ciphers HIGH:!aNULL:!MD5;

ssl_prefer_server_ciphers on;

Load configuration files for the default server block.

include /etc/nginx/default.d/*.conf;

location / {

}

error_page 404 /404.html;

location = /40x.html {

}

error_page 500 502 503 504 /50x.html;

location = /50x.html {

}

}

}

我的配置文件：/etc/nginx/conf.d/hyt.conf

server {

listen       80 default_server;
listen       [::]:80 default_server;
server_name  hyt.cms.com;

location / {
    root   /home/project/hyt_cms/src/web/;
    proxy_pass       http://127.0.0.1:8080;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header Host $host;
    # proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-For $remote_addr;
}

location /static {
    root /home/project/hyt_cms/src/web/;
}

location /templates {
    root /home/project/hyt_cms/src/web/templates/;
}

error_page   500 502 503 504  /50x.html;
location = /50x.html {
    root   /usr/share/nginx/html;
}

charset utf-8;
access_log  /var/log/nginx/hyt.cms.com.access.log;
error_log  /var/log/nginx/hyt.cms.com.error.log;

}

[root@iZuf6igcce8m64xznu8cvvZ nginx]# vim /etc/sysconfig/iptables

sample configuration for iptables service

you can edit this manually or use system-config-firewall

please do not ask us to add additional ports/services to this default configuration

*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT