private (Output<string> registryUsername, Output<string> registryPassword) GetRegistryLogin(Output<string> resourceGroupName, Output<string> registryName)
{
    var credentials = Output.Tuple(resourceGroupName, registryName).Apply(values =>
        ListRegistryCredentials.InvokeAsync(new ListRegistryCredentialsArgs
        {
            ResourceGroupName = values.Item1,
            RegistryName = values.Item2
        }));
    var registryUsername = credentials.Apply(c => c.Username ?? "");
    var registryPassword = credentials.Apply(c => Output.CreateSecret(c.Passwords.First().Value ?? ""));
    return (registryUsername, registryPassword);
}