Portanto, o navegador enviará uma requisição HTTP `OPTIONS` ao backend `:80`, e se o backend enviar os cabeçalhos apropriados autorizando a comunicação a partir dessa origem diferente (`http://localhost:8080`), então o navegador `:8080` permitirá que o JavaScript no frontend envie sua requisição para o backend `:80`.

Para conseguir isso, o backend `:80` deve ter uma lista de "origens permitidas".

  - [Changelog since v1.8.0](#changelog-since-v180)
    - [Action Required](#action-required-2)
    - [Other notable changes](#other-notable-changes-14)
- [v1.8.0](#v180)
  - [Downloads for v1.8.0](#downloads-for-v180)
    - [Client Binaries](#client-binaries-15)
    - [Server Binaries](#server-binaries-15)
    - [Node Binaries](#node-binaries-15)
  - [Introduction to v1.8.0](#introduction-to-v180)

Потім браузер надішле HTTP-запит `OPTIONS` до бекенду на порту `:80`, і якщо бекенд надішле відповідні заголовки, що дозволяють комунікацію з цього іншого джерела (`http://localhost:8080`), тоді браузер на порту `:8080` дозволить JavaScript у фронтенді надіслати свій запит до бекенду на порту `:80`.

Щоб досягти цього, бекенд на порту `:80` повинен мати список "дозволених джерел".

Then, the browser will send an HTTP `OPTIONS` request to the `:80`-backend, and if the backend sends the appropriate headers authorizing the communication from this different origin (`http://localhost:8080`) then the `:8080`-browser will let the JavaScript in the frontend send its request to the `:80`-backend.

To achieve this, the `:80`-backend must have a list of "allowed origins".

    assertUnescaped(e, '*');

    assertEscaping(e, "%00", '\u0000'); // nul
    assertEscaping(e, "%7F", '\u007f'); // del
    assertEscaping(e, "%C2%80", '\u0080'); // xx-00010,x-000000
    assertEscaping(e, "%DF%BF", '\u07ff'); // xx-11111,x-111111
    assertEscaping(e, "%E0%A0%80", '\u0800'); // xxx-0000,x-100000,x-00,0000
    assertEscaping(e, "%EF%BF%BF", '\uffff'); // xxx-1111,x-111111,x-11,1111

        transaction.setTotalDataCount(200);
        transaction.setMaxParameterCount(1024);
        transaction.setMaxDataCountForTest(2048);
        transaction.setParameterCount(50);
        transaction.setParameterOffset(80);
        transaction.setDataCount(150);
        transaction.setDataOffset(130);
        transaction.setSetupCount(1);
        transaction.setSetupWireFormatReturn(4);

        // Execute the method

		globalMinioHost, globalMinioPort = host, port
	}()
	testCases := []struct {
		host, port     string
		expectedResult string
	}{
		{"", "80", "http://127.0.0.1:80"},
		{"127.0.0.1", "80", "http://127.0.0.1:80"},
		{"localhost", "80", "http://localhost:80"},
	}

	for i, testCase := range testCases {
		globalMinioHost, globalMinioPort = testCase.host, testCase.port
		apiEndpoints := getAPIEndpoints()

  }

  public void testRfc2202_hmacSha1_case6() {
    byte[] key = fillByteArray(80, 0xaa);
    String data = "Test Using Larger Than Block-Size Key - Hash Key First";

    checkSha1("aa4ae5e15272d00e95705637ce8a3b55ed402112", key, data);
  }

  public void testRfc2202_hmacSha1_case7() {
    byte[] key = fillByteArray(80, 0xaa);
    String data = "Test Using Larger Than Block-Size Key and Larger Than One Block-Size Data";

Dann wird der Browser ein HTTP-`OPTIONS`-<abbr title="Request – Anfrage: Daten, die der Client zum Server sendet">Request</abbr> an das `:80`-Backend senden, und wenn das Backend die entsprechenden Header sendet, die die Kommunikation von diesem anderen Origin (`http://localhost:8080`) autorisieren, lässt der `:8080`-Browser das JavaScript im Frontend seinen Request an das `:80`-Backend senden.

  export IP_ADDR=$(powershell -command "(Get-NetIPAddress -AddressFamily IPv4 -InterfaceAlias 'vEthernet (nat)').IPAddress")
  netsh interface portproxy add v4tov4 listenaddress=$IP_ADDR listenport=80 connectaddress=169.254.169.254 connectport=80
  # A local firewall rule for the container is added in
  # ci/official/utilities/setup_docker.sh.
else
  # The volume mapping flag below shares the user's gcloud credentials, if any,