var options = new HealthCheckOptions
{
    ResponseWriter = async (c, r) =>
    {
        c.Response.ContentType = "application/json";

        string result = JsonConvert.SerializeObject(new
        {
            status = r.Status.ToString(),
            errors = r.Entries.Select(e => new
            {
                key = e.Key,
                value = e.Value.Status.ToString()
            })
        });

        await c.Response.WriteAsync(result);
    }
};

app.Map("/health", a =>
{
    a.Use(async (context, next) =>
    {
        if (context.User.Identity.IsAuthenticated)
        {
            await next.Invoke();
            return;
        }

        context.Response.StatusCode = (int)HttpStatusCode.Unauthorized;
    });

    a.UseMiddleware<HealthCheckMiddleware>(Options.Create(options));
});