反向代理失败并出现未知错误

Question

我正在尝试自行托管可信分析。到目前为止，我已经安装了 docker，并启动了 docker 容器。我还确保 nginx 正在运行、具有有效配置、通过 ufw 允许端口 80 和 443，并使用域配置了 nginx https://plausible.example.com：。

我的 nginx 配置如下：

   server {
    server_name plausible.example.com;

    location / {
        proxy_pass http://localhost:8000;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }

    listen [::]:443 ssl; # managed by Certbot
    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/plausible.example.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/plausible.example.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

}

 server {
    if ($host = plausible.example.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    server_name plausible.example.com;

    listen 80;
    listen [::]:80;
    return 404; # managed by Certbot 
}

问题是当我尝试访问时plausible.example.com出现502 bad gateway错误。当我检查 nginx 错误日志时，我收到此错误：

[error] 935230#935230: *579224 recv() failed (104: Unknown error) while reading response header from upstream

我尝试找到此错误的解决方案，但一直没有成功。如能得到任何帮助，我将不胜感激。谢谢。

编辑：我还应该补充一点，在合理的环境变量中，主机名是：https://plausible.example.com