the system is Ubuntu 16.04 . After configuring the security group, visit Nginx and visit IP to see the welcome page of Nginx . But after configuring Nginx , delete the default file under sites-enabled , and simply refuse access. Visit IP prompt:

Unable to round-trip http request to upstream: dial tcp4 xx.xx.xx.xx:80: connect: connection refused

Nginx is configured as follows:

server {
    charset utf-8;
    listen 80;
    server_name xx.xx.xx.xxx; -sharp IP

    location /static {
        alias /home/zeleven/sites/zee/zee/staticfiles; -sharp Django 
    }

    location / {
        proxy_set_header Host $host;
        proxy_pass http://unix:/tmp/xxxx.socket;
    }
}