caCertPool.AppendCertsFromPEM(caCert)

	// creating https client with client certificate and certificate authority
	httpsClient := &http.Client{
		Transport: &http.Transport{
			TLSClientConfig: &tls.Config{
				RootCAs:    caCertPool,
				MinVersion: tls.VersionTLS12,
			},
		},
	}

	server := NewJwtServer(serverCert, serverKey)

	// Start the test server on port 8443.
	go server.runHTTPS(":8443")

	// Request to an advertised but unhandled NPN protocol.
	// Server will hang up.
	{
		certPool := x509.NewCertPool()
		certPool.AddCert(ts.Certificate())
		tr := &Transport{
			TLSClientConfig: &tls.Config{
				RootCAs:    certPool,
				NextProtos: []string{"unhandled-proto"},
			},
		}
		defer tr.CloseIdleConnections()
		c := &Client{
			Transport: tr,
		}
		res, err := c.Get(ts.URL)
		if err == nil {

	} else if r.CaCert != "" {
		certPool := x509.NewCertPool()
		if !certPool.AppendCertsFromPEM([]byte(r.CaCert)) {
			return nil, fmt.Errorf("failed to create cert pool")
		}
		tlsConfig.RootCAs = certPool
	}

	setALPNForHTTP := func() {
		if r.Alpn == nil {
			switch {
			case r.Http3:
				// Do nothing.
			case r.Http2:
				tlsConfig.NextProtos = []string{"h2"}
			default:

			return nil, fmt.Errorf("failed to create cert pool")
		}
		cfg := credentials.NewTLS(&tls.Config{Certificates: []tls.Certificate{cert}, RootCAs: certPool, MinVersion: tls.VersionTLS12})
		// If provided, override the hostname
		if tlsSettings.Hostname != "" {
			dialOptions = append(dialOptions, grpc.WithAuthority(tlsSettings.Hostname))
		}

					Certificates: []tls.Certificate{cert},
				}
				ts.StartTLS()
				return ts
			},
			ProxyTransport: utilnet.SetTransportDefaults(&http.Transport{TLSClientConfig: &tls.Config{RootCAs: localhostPool}}),
		},
		"https (valid hostname + RootCAs + custom dialer)": {
			ServerFunc: func(h http.Handler) *httptest.Server {
				cert, err := tls.X509KeyPair(localhostCert, localhostKey)
				if err != nil {

		if err != nil {
			return nil, err
		}
		tlsConfig = &tls.Config{Certificates: []tls.Certificate{cert}}
	}

	if caCert != nil {
		rootCAs := x509.NewCertPool()
		rootCAs.AppendCertsFromPEM(caCert)
		if tlsConfig == nil {
			tlsConfig = &tls.Config{}
		}
		tlsConfig.ClientCAs = rootCAs
		tlsConfig.ClientAuth = tls.RequireAndVerifyClientCert
	}

	serveHTTP := func(w http.ResponseWriter, r *http.Request) {

			return nil, err
		}
		tlsConfig = &tls.Config{Certificates: []tls.Certificate{cert}}
	}

	if caCert != nil {
		rootCAs := x509.NewCertPool()
		rootCAs.AppendCertsFromPEM(caCert)
		if tlsConfig == nil {
			tlsConfig = &tls.Config{}
		}
		tlsConfig.ClientCAs = rootCAs
		tlsConfig.ClientAuth = tls.RequireAndVerifyClientCert
	}

	serveHTTP := func(w http.ResponseWriter, r *http.Request) {

func GetDefaultConnSettings() xhttp.ConnSettings {
	return xhttp.ConnSettings{
		LookupHost:  globalDNSCache.LookupHost,
		DialTimeout: rest.DefaultTimeout,
		RootCAs:     globalRootCAs,
		TCPOptions:  globalTCPOptions,
	}
}

// NewInternodeHTTPTransport returns a transport for internode MinIO
// connections.

	if err != nil {
		return nil, fmt.Errorf("failed to get application default credentials: %w", err)
	}

	return []grpc.DialOption{
		grpc.WithTransportCredentials(credentials.NewTLS(&tls.Config{
			RootCAs:    systemRoots,
			MinVersion: tls.VersionTLS12,
		})),
		grpc.WithPerRPCCredentials(&meshAuthCredentials{
			k8sCreds: k8sCreds,
			gcpCreds: gcpCreds,
			project:  gcpProject,
		}),
	}, nil

	certPool := x509.NewCertPool()
	ok := certPool.AppendCertsFromPEM(rootCert)
	if !ok {
		return nil, fmt.Errorf("failed to append certificates")
	}
	config := tls.Config{
		RootCAs:            certPool,
		InsecureSkipVerify: true, // nolint: gosec // test only code
	}
	transportCreds := credentials.NewTLS(&config)

	conn, err := grpc.Dial(endpoint, grpc.WithTransportCredentials(transportCreds))