ip = v.IP
			case *net.IPAddr:
				ip = v.IP
			}

			ipList = append(ipList, ip)
		}
	}

	return ipList
}

func mustGetLocalLoopbacks() (ipList set.StringSet) {
	ipList = set.NewStringSet()
	for _, ip := range mustGetLocalIPs() {
		if ip != nil && ip.IsLoopback() {
			ipList.Add(ip.String())
		}
	}
	return ipList
}

// mustGetLocalIP4 returns IPv4 addresses of localhost.  It panics on error.

На DNS‑сервере(ах) вы настроите запись («`A record`» - запись типа A), указывающую, что **ваш домен** должен указывать на публичный **IP‑адрес вашего сервера**.

Обычно это делается один раз — при первоначальной настройке всего.

/// tip | Совет

Часть про доменное имя относится к этапам задолго до HTTPS, но так как всё зависит от домена и IP‑адреса, здесь стоит это упомянуть.

///

///

### DNS { #dns }

Konzentrieren wir uns nun auf alle tatsächlichen HTTPS-Aspekte.

Zuerst würde der Browser mithilfe der **DNS-Server** herausfinden, welches die **IP für die Domain** ist, in diesem Fall `someapp.example.com`.

		// with the approach we took for returning first ip from multiple
		// params.
		if match := forRegex.FindStringSubmatch(proto); len(match) > 1 {
			if match = protoRegex.FindStringSubmatch(match[2]); len(match) > 1 {
				scheme = strings.ToLower(match[2])
			}
		}
	}

	return scheme
}

// GetSourceIPFromHeaders retrieves the IP from the X-Forwarded-For, X-Real-IP
// and RFC7239 Forwarded headers (in that order)

在 DNS 服务器中，你可以配置一条记录（“A 记录”）以将 **你的域名** 指向你服务器的公共 **IP 地址**。

这个操作一般只需要在最开始执行一次。

/// tip

域名这部分发生在 HTTPS 之前，由于这一切都依赖于域名和 IP 地址，所以先在这里提一下。

///

### DNS

现在让我们关注真正的 HTTPS 部分。

首先，浏览器将通过 **DNS 服务器** 查询**域名的IP** 是什么，在本例中为 `someapp.example.com`。

DNS 服务器会告诉浏览器使用某个特定的 **IP 地址**。 这将是你在 DNS 服务器中为你的服务器配置的公共 IP 地址。

///

### DNS { #dns }

Agora vamos focar em todas as partes que realmente fazem parte do HTTPS.

Primeiro, o navegador iria verificar com os servidores DNS qual o IP do domínio, nesse caso, `someapp.example.com`.

	t := time.Now().UTC()
	for ip := range c.domainIPs {
		bucketMsg, err := newCoreDNSMsg(ip, c.domainPort, defaultTTL, t)
		if err != nil {
			return err
		}
		for _, domainName := range c.domainNames {
			key := msgPath(fmt.Sprintf("%s.%s", bucket, domainName), c.prefixPath)
			key = key + etcdPathSeparator + ip
			ctx, cancel := context.WithTimeout(context.Background(), defaultContextTimeout)

In the DNS server(s) you would configure a record (an "`A record`") to point **your domain** to the public **IP address of your server**.

You would probably do this just once, the first time, when setting everything up.

/// tip

This Domain Name part is way before HTTPS, but as everything depends on the domain and the IP address, it's worth mentioning it here.

///

	addrs, err := net.InterfaceAddrs()
	if err != nil {
		t.Fatalf("%s.  Unable to get IP addresses of this host.", err)
	}

	for _, addr := range addrs {
		var ip net.IP
		switch v := addr.(type) {
		case *net.IPNet:
			ip = v.IP
		case *net.IPAddr:
			ip = v.IP
		}

		if ip.To4() != nil {
			localIP4.Add(ip.String())
		}
	}

	// Filter ipList by IPs those do not start with '127.'.

            proxy_set_header Host $http_host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_set_header X-NginX-Proxy true;

            # This is necessary to pass the correct IP to be hashed
            real_ip_header X-Real-IP;

            proxy_connect_timeout 300;