Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    services.AddHealthChecks(checks =>
    {
        // Local DB Check is just the name of the Health Check.  You can call it whatever you want.
        checks.AddSqlCheck("SQL DB Check", "Server=(localdb)\\mssqllocaldb;Database=aspnet-WebApplication1;Trusted_Connection=True;MultipleActiveResultSets=true");
    });

    services.AddMvc();
}