网页502 Bad Gateway nginx/1.20.1报错的原因与解决方法

proxy_set_header Host $host;
proxy_set_header X-Real-IP    $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

# For more information on configuration, see:
# * Official English Documentation: http://nginx.org/en/docs/
# * Official Russian Documentation: http://nginx.org/en/docs/
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
#Load dynamic modules. See /usr/share/doc/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	4096;

    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;
    proxy_buffering off; 
    upstream chatgpt-web {
	server 127.0.0.1:网关 weight=1;
}

    server {
      listen 80;
      server_name www.域名;
      location / {
    rewrite ^(.*)$ https://www.域名; 
  }
}

    server {
      listen 443 ssl;
      server_name www.域名;
      ssl_certificate /etc/nginx/（SSL的pem文件名）;
      ssl_certificate_key /etc/nginx/（SSL的key文件名）;
  location / {
	proxy_pass http://chatgpt-web;
  }     
}


# Settings for a TLS enabled server.
#
#    server {
#        listen       443 ssl http2;
#        listen       [::]:443 ssl http2;
#        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;
#
#        error_page 404 /404.html;
#            location = /40x.html {
#        }
#
#        error_page 500 502 503 504 /50x.html;
#            location = /50x.html {
#        }
#    }

}

nginx -t