Load database table as IOption<> at startup - entity-framework

Question

.Net Core 3.1 application. ConfigureServices in Startup.cs sets up an EF Core 5 DbContext. One of the "static" tables I wish to load into memory and make available via a AddOptions to make the table injectible throughout the application (cheap man's caching). Same as BINDing from appsettings but using an EF Core database.
I already "seed" the database in Main by creating a scope and getting the DbContext service to run an initialization method. That technique won't work in this case because I am adding a service. Is there a way to read the DbContext while I am still in ConfigureServices? A way to add a service once the Host is built but not run?
How would you approach this?

Answer 1

Wouldn't you know. I post the question and kept reframing my search terms and digging and voila.
Using IConfigureOptions
So I created a class
using MyContexts;
using MyModels;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using System.Linq;
public class LoadMySettings : IConfigureOptions<MySettings>
{
private readonly IServiceScopeFactory _serviceScopeFactory;
public LoadMySettings(IServiceScopeFactory serviceScopeFactory)
{
_serviceScopeFactory = serviceScopeFactory;
}
public void Configure(MySettings options)
{
using (var scope = _serviceScopeFactory.CreateScope())
{
var provider = scope.ServiceProvider;
using (var dbContext = provider.GetRequiredService<MyContext>())
{
options.MySettingsList = dbContext.MySettingsTable.ToList();
}
}
}
}
and embedded this in ConfigureServices:
services.AddSingleton>IConfigureOptions<MySettinmgs>, LoadMySettings>();