import okhttp3.Dns.Companion.SYSTEM

/**
 * A domain name service that resolves IP addresses for host names. Most applications will use the
 * [system DNS service][SYSTEM], which is the default. Some applications may provide their own
 * implementation to use a different DNS server, to prefer IPv6 addresses, to prefer IPv4 addresses,
 * or to force a specific known IP address.
 *
 * Implementations of this interface must be safe for concurrent use.
 */

    /**
     * Check whether a hostname is actually an ip address
     * 
     * @param hostname
     * @return whether this is an IP address
     */
    public static boolean isDotQuadIP ( String hostname ) {
        if ( Character.isDigit(hostname.charAt(0)) ) {
            int i, len, dots;
            char[] data;

            i = dots = 0; /* quick IP address validation */
            len = hostname.length();

	// and the operator can investigate.
	//
	// This is also important to avoid ipset sync issues if we add the pod ip to the ipset, but
	// enrolling fails because ztunnel (or the pod netns, or whatever) isn't ready yet,
	// and the pod is rescheduled with a new IP. In that case we don't get
	// a removal event, and so would never clean up the old IP that we eagerly-added.
	//
	// TODO one place this *can* fail is

MinIO can be accessed via port {{ .Values.service.port }} on an external IP address. Get the service external IP address by:
kubectl get svc --namespace {{ .Release.Namespace }} -l app={{ template "minio.fullname" . }}

Note that the public IP may take a couple of minutes to be available.

You can now access MinIO server on http://<External-IP>:9000. Follow the below steps to connect to MinIO server with mc client:

			sortedIPList: []string{"127.0.0.1"},
		},
		// Non parsable ip is assumed to be hostame and gets preserved
		// as the left most elements, regardless of IP based sorting.
		{
			ipList:       []string{"hostname", "127.0.0.1", "192.168.1.106"},
			sortedIPList: []string{"hostname", "192.168.1.106", "127.0.0.1"},
		},
		// Non parsable ip is assumed to be hostname, with a mixed input of ip and hostname.

<img src="/img/deployment/https/https01.svg">

### TLS Handshake の開始

ブラウザはIPアドレスと**ポート443**（HTTPSポート）で通信します。

通信の最初の部分は、クライアントとサーバー間の接続を確立し、使用する暗号鍵などを決めるだけです。

<img src="/img/deployment/https/https02.svg">

TLS接続を確立するためのクライアントとサーバー間のこのやりとりは、**TLSハンドシェイク**と呼ばれます。

### SNI拡張機能付きのTLS

サーバー内の**1つのプロセス**だけが、特定 の**IPアドレス**の特定の**ポート** で待ち受けることができます。

            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;
            

	for _, configuredPodIPs := range addCmd.IPs {
		// net.ip is implicitly convertible to netip as slice
		ip, _ := netip.AddrFromSlice(configuredPodIPs.Address.IP)
		// We ignore the mask of the IPNet - it's fine if the IPNet defines
		// a block grant of addresses, we just need one for checking routes.
		podIps = append(podIps, ip.Unmap())
	}

            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;
            

            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;