502 nginx上的坏网关

Question

我在nginx上得到502个坏网关，有以下错误：

[error] 1679#1679: *13 connect() failed (111: Connection refused) while connecting to upstream, client: 46.176.252.229, server: dodeka-designers.com, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:3000/", host: "dodeka-designers.com"

这是我的/etc/nginx/sites-available/default内容。有谁知道这个问题可能是什么吗？

server {
    listen 80;
        server_name dodeka-designers.com www.dodeka-designers.com;
    location ~ /.well-known {
                allow all;
        }

    location / {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
        client_max_body_size 50M;
    }

    location /back {
        if ($request_method = 'OPTIONS') {
            add_header 'Access-Control-Allow-Origin' '*';
            add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
            add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';
            add_header 'Access-Control-Max-Age' 1728000;
            add_header 'Content-Type' 'text/plain charset=UTF-8';
            add_header 'Content-Length' 0;
            return 200;
        }
        if ($request_method = 'POST') {
            add_header 'Access-Control-Allow-Origin' '*';
            add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
            add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';
            add_header 'Access-Control-Expose-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';
        }
        if ($request_method = 'GET') {
            add_header 'Access-Control-Allow-Origin' '*';
            add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
            add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';
            add_header 'Access-Control-Expose-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Content-Range,Range';
        }
        rewrite ^/back(.*)$ $1 break;
        root /var/www/html;

        client_max_body_size 50M;
            proxy_http_version 1.1;
        proxy_connect_timeout       3600;
        proxy_send_timeout          3600;
        proxy_read_timeout          3600;
        send_timeout                3600;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;

        index index.php index.html index.htm;
    }

    location ~ \.php$ {

        rewrite ^/back(.*)$ $1 break;
        root /var/www/html;

        include snippets/fastcgi-php.conf;
        fastcgi_pass unix:/run/php/php7.0-fpm.sock;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;

        client_max_body_size 50M;
            proxy_http_version 1.1;
        proxy_connect_timeout       3600;
        proxy_send_timeout          3600;
        proxy_read_timeout          3600;
        send_timeout                3600;
        fastcgi_read_timeout        3600;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }



    listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/dodeka-designers.com/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/dodeka-designers.com/privkey.pem; # managed by Certbot
  include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
  ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
 }

Answer 1

您正在运行一个反向代理，该代理试图连接到“http://localhost:3000‘”上的另一个服务，因此此错误不在nginx上，因为本地主机上的另一个服务:3000没有响应nginx请求，或者它没有正确地回答它以由反向代理处理(例如，它正在产生重定向)。

如果您是able (例如，通过telnet连接到端口3000 )(命令执行此测试：telnet localhost 3000)，请检查它是用纯文本进行的，还是以外壳形式(https.)--因为您将nginx配置为仅连接到http的其他服务，如果无法连接到端口3000，则必须确定您在此端口中应该修复的服务，nginx与此无关。

You并不期望nginx是‘反向代理？？那么您需要编辑它的配置来删除“代理”行。