server.useHttps(handshakeCertificates.sslSocketFactory())

    val dns =
      Dns {
        Dns.SYSTEM.lookup(server.hostName)
      }

    val client =
      clientTestRule
        .newClientBuilder()
        .sslSocketFactory(
          handshakeCertificates.sslSocketFactory(),
          handshakeCertificates.trustManager,
        ).dns(dns)
        .build()

    server.enqueue(MockResponse())

...
01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] responseHeadersEnd: Response{protocol=h2, code=200, message=, url=https://1.1.1.1/dns-query?dns=AAABAAABAAAAAAAAA3d3dwhmYWNlYm9vawNjb20AABwAAQ}
01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] responseBodyStart
01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] responseBodyEnd: byteCount=128

## Get started

### 1. Prerequisites

Install MinIO - [MinIO Quickstart Guide](https://docs.min.io/community/minio-object-store/operations/deployments/baremetal-deploy-minio-on-redhat-linux.html).

### 2. Run MinIO in federated mode

Bucket lookup from DNS federation requires two dependencies

- etcd (for bucket DNS service records)

        .newBuilder()
        .dns {
          Dns.SYSTEM.lookup("sni.cloudflaressl.com")
        }.build()

    val request =
      Request
        .Builder()
        .url("https://cloudflare-dns.com/cdn-cgi/trace")
        .build()
    client.newCall(request).execute().use { response ->
      assertThat(response.code).isEqualTo(200)
      assertThat(response.protocol).isEqualTo(Protocol.HTTP_2)

  )
  fun url(): HttpUrl = url

  @JvmName("-deprecated_dns")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "dns"),
    level = DeprecationLevel.ERROR,
  )
  fun dns(): Dns = dns

  @JvmName("-deprecated_socketFactory")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "socketFactory"),

package okhttp3.internal

import java.net.InetAddress
import okhttp3.Dns

/**
 * A network that always resolves two IP addresses per host. Use this when testing route selection
 * fallbacks to guarantee that a fallback address is available.
 */
class DoubleInetAddressDns : Dns {
  override fun lookup(hostname: String): List<InetAddress> {
    val addresses = Dns.SYSTEM.lookup(hostname)
    return listOf(addresses[0], addresses[0])
  }

      ),
    )
    server!!.enqueue(MockResponse())
    val dns = FakeDns()
    dns["fakeurl"] = client.dns.lookup(server!!.hostName)
    dns["www.fakeurl"] = client.dns.lookup(server!!.hostName)
    client =
      client
        .newBuilder()
        .dns(dns)
        .build()
    val call =
      client.newCall(
        Request
          .Builder()

import java.net.InetAddress
import java.net.UnknownHostException
import okhttp3.Dns

/**
 * Internal Bootstrap DNS implementation for handling initial connection to DNS over HTTPS server.
 *
 * Returns hardcoded results for the known host.
 */
internal class BootstrapDns(
  private val dnsHostname: String,
  private val dnsServers: List<InetAddress>,
) : Dns {
  @Throws(UnknownHostException::class)

 * configure the factory when sample values impact the correctness of the test.
 */
class TestValueFactory : Closeable {
  var taskFaker: TaskFaker = TaskFaker()
  var taskRunner: TaskRunner = taskFaker.taskRunner
  var dns: Dns = Dns.SYSTEM
  var proxy: Proxy = Proxy.NO_PROXY
  var proxySelector: ProxySelector = RecordingProxySelector()
  var proxyAuthenticator: Authenticator = RecordingOkAuthenticator("password", null)

///

### 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 für `someapp.example.com`.

Die DNS-Server geben dem Browser eine bestimmte **IP-Adresse** zurück. Das wäre die von Ihrem Server verwendete öffentliche IP-Adresse, die Sie in den DNS-Servern konfiguriert haben.