问如何确认来自Go客户端的gRPC流量是否经过TLS加密

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    // block the dial until connection is successful or 3 sec timeout
    dialOptions := []grpc.DialOption{
        grpc.WithBlock(),
        grpc.WithTimeout(3 * time.Second),
    }

    // Load TLS Configuration
    tlsCredentials, err := LoadTLSCredentials()
    if err != nil {
        log.Fatalf("Failed to load TLS credentials: %v", err)
    }

    dialOptions = append(dialOptions, grpc.WithTransportCredentials(tlsCredentials))

    // Dial the gRPC server
    log.Printf("Dialing %v", *address)
    conn, err := grpc.Dial(*address, dialOptions...)
    if err != nil {
        log.Fatalf("Failed to connect to the server: %v", err)
    }
    defer conn.Close()

    // then this application sets up a gRPC request, and logs the response to stdout,
    // in my testing stdout shows the expected gRPC response, so I'd assume TLS is working.


func LoadTLSCredentials() (credentials.TransportCredentials, error) {
    rootCA, err := ioutil.ReadFile("ca.cert")
    if err != nil {
        return nil, err
    }

    certPool := x509.NewCertPool()
    if !certPool.AppendCertsFromPEM(rootCA) {
        return nil, fmt.Errorf("Failed to add rootCA to x509 certificate pool")
    }

    config := &tls.Config{
        MinVersion: tls.VersionTLS12,
        RootCAs: certPool,
    }

    return credentials.NewTLS(config), nil
}