nginx: [emerg] host not found in upstream "cdn.xieboke.net" in /usr/local/nginx/conf/vhost/joyo.ink.conf:38

错误日志

[root@VM_2_29_centos ~]# systemctl status nginx -l
● nginx.service - nginx
   Loaded: loaded (/etc/systemd/system/nginx.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Thu 2021-03-25 16:27:52 CST; 7min ago
  Process: 493 ExecStart=/usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf (code=exited, status=1/FAILURE)

Mar 25 16:27:52 VM_2_29_centos systemd[1]: Starting nginx...
Mar 25 16:27:52 VM_2_29_centos nginx[493]: nginx: [emerg] host not found in upstream "cdn.xieboke.net" in /usr/local/nginx/conf/vhost/joyo.ink.conf:38
Mar 25 16:27:52 VM_2_29_centos systemd[1]: nginx.service: control process exited, code=exited status=1
Mar 25 16:27:52 VM_2_29_centos systemd[1]: Failed to start nginx.
Mar 25 16:27:52 VM_2_29_centos systemd[1]: Unit nginx.service entered failed state.
Mar 25 16:27:52 VM_2_29_centos systemd[1]: nginx.service failed.

systemd 配置文件

vim /etc/systemd/system/uwsgi.service

[Unit]
Description=uwsgi
After=network.target

[Service]
Type=notify
ExecStart=/root/.virtualenvs/joyoo/bin/uwsgi --ini /root/yzq/djangos/blog/blog_uwsgi.ini
ExecReload=/root/.virtualenvs/joyoo/bin/uwsgi --reload /root/yzq/running/uwsgi_joyoo.pid
ExecStop=/root/.virtualenvs/joyoo/bin/uwsgi --stop /root/yzq/running/uwsgi_joyoo.pid
Restart=always

[Install]
WantedBy=multi-user.target

# 重载系统服务，因添加了 nginx.server
sudo systemctl daemon-reload
# 启动 nginx
sudo systemctl start nginx
# 停止 nginx
sudo systemctl stop nginx
# 查看 nginx 状态
sudo systemctl status nginx
# 设置开机启动
sudo systemctl enable nginx
# 取消开机启动
sudo systemctl disable nginx

nginx 配置文件

nginx -t 都是没问题的

[root@VM_2_29_centos ~]# cat /usr/local/nginx/conf/vhost/joyo.ink.conf
server {
        listen       80;
        # listen       443;
        server_name  joyo.ink www.joyo.ink;
        charset utf-8;
        client_max_body_size  50m;

        # ssl on;
        # ssl_certificate      /root/yzq/djangos/blog/certificate/xiebole.net/Nginx/1_xieboke.net_bundle.crt;
        # ssl_certificate_key  /root/yzq/djangos/blog/certificate/xiebole.net/Nginx/2_xieboke.net.key;

        # ssl_session_cache    shared:SSL:1m;
        # ssl_session_timeout  5m;

        # ssl_ciphers  HIGH:!aNULL:!MD5;
        # ssl_prefer_server_ciphers  on;

        access_log  /root/yzq/logs/joyo.ink.access.log;
        error_log   /root/yzq/logs/joyo.ink.error.log;

        if ($server_port = "443") {
              return 302 http://$host$request_uri;
         }

        location / {
             uwsgi_pass 127.0.0.1:9090;
             include uwsgi_params;
    #        root   html;
    #        index  index.html index.htm;
        }

    	location /media {
		     alias /root/yzq/djangos/blog/media;
	    }

	    location /static {
		    # alias /root/yzq/djangos/blog/static_root;
		    proxy_pass http://cdn.xieboke.net/static_root;
            # rewrite /static/(.*) http://cdn.xieboke.net/static_root/$1;
	    }

 }
   


[root@VM_2_29_centos ~]# nginx -t
nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful

利用 nginx 进行反向代理的时候，我们会配置 proxy_pass。在启动 nginx 的时候，会报：

nginx: [emerg] host not found in upstream "cdn.xieboke.net" in /usr/local/nginx/conf/vhost/joyo.ink.conf:38

其实 nginx 配置语法上没有错误的，只是系统无法解析这个域名，所以报错。

解决办法

就添加 dns 到 /etc/resolv.conf 或者是 /etc/hosts, 让其能够解析到IP。

具体步骤如下：

vim /etc/hosts

修改hosts文件，在hosts文件里面加上一句

127.0.0.1    localhost.localdomain    cdn.xieboke.net