Problem with using .Net 6 minimal hosting

Hi

I’m trying to use Lamar with the default .Net 6 Web API project generated by Visual Studio 2022.

The following minimal Program.cs works (without Lamar):

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllers();

var app = builder.Build();

app.MapControllers();

app.Run();

I can access their example WeatherForecastController here:

http://localhost:5156/weatherforecast

If I then add this Lamar dependency:

<PackageReference Include="Lamar.Microsoft.DependencyInjection" Version="7.1.1" />

According the the documentation here:

  https://jasperfx.github.io/lamar/guide/#lamar-with-asp-net-core-minimal-hosting

I would expect this Program.cs to work:

using Lamar.Microsoft.DependencyInjection;

var builder = WebApplication.CreateBuilder(args);

builder.Host.UseLamar((context, registry) =>
{
    registry.AddControllers();
});

var app = builder.Build();

app.MapControllers();

app.Run();

But I get a 404 error when trying to access http://localhost:5156/weatherforecast.

The Kestrel log shows:

      info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
            Request starting HTTP/1.1 GET http://localhost:5156/weatherforecast - -
      dbug: Microsoft.AspNetCore.HostFiltering.HostFilteringMiddleware[0]
            Wildcard detected, all requests with hosts will be allowed.
      dbug: Microsoft.AspNetCore.Routing.Matching.DfaMatcher[1000]
            No candidates found for the request path '/weatherforecast'
      dbug: Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware[2]
            Request did not match any endpoints
      dbug: Microsoft.AspNetCore.Server.Kestrel.Connections[9]
            Connection id "0HMF4N473N8HB" completed keep alive response.
      info: Microsoft.AspNetCore.Hosting.Diagnostics[2]
            Request finished HTTP/1.1 GET http://localhost:5156/weatherforecast - - - 404 0 - 541.4319ms

However this Program.cs works fine:

using Lamar.Microsoft.DependencyInjection;

var builder = WebApplication.CreateBuilder(args);

builder.Host.UseLamar();

builder.Host.ConfigureContainer<Lamar.ServiceRegistry>(services =>
{
    services.AddControllers();
});

var app = builder.Build();

app.MapControllers();

app.Run();

Is the documentation at https://jasperfx.github.io/lamar/guide/#lamar-with-asp-net-core-minimal-hosting still applicable to .Net 6 minimal hosting?

[jeremydmiller]

@tmc101 Short term, yeah, take AddControllers() outside of UseLamar(). I’ll try to address this early next week and change the mechanics ever so slightly of UseLamar() so that it’s being applied against the host builder’s ServiceCollection and see if I can fix that permanently.

I’d rather hold off just at the moment to see if that can be fixed. Folks don’t read the docs generally anyway, so I’d rather try to actually fix it.

[tmc101]

This look like a duplication of https://github.com/JasperFx/lamar/issues/320

The documentation needs to be updated - as the ‘Hello World’ example doesn’t work.