Investigate interaction between UseProxyToSpaDevelopmentServer and UseEndpoints

[rafaelfgx]

No description provided.

[mkArtakMSFT]

@captainsafia, @JamesNK do you know if is this a newly added analyzer suggesting this change and is the proposed change truly equivalent to the original code?

[javiercn]

@rafaelfgx thanks for contacting us.

You shouldn't need to call app.UseRouting nor app.UseEndpoints if you are using minimal hosting (as you seem to be doing) as the host already wraps the pipeline with app.UseRouting and app.UseEndpoints.

You can call MapControllers directly on the builder. I believe mix and matching is not supported.

[brunolins16]

@rafaelfgx I have tested without app.UseRouting and app.UseEndpoints, as mentioned, and it should work. Can you share a repro?

[ghost]

Hi @rafaelfgx. We have added the "Needs: Author Feedback" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[halter73]

@brunolins16 Did you try with UseRouting but not UseEndpoints? That should also work.

[HarelM]

I've stumbled across this issue as well I believe as can be read in my comment here: #42937 (comment)
For some reason the commit is not in the post, the following is the relevant commit I did in order to revert back to a working state:
IsraelHikingMap/Site@419b98b
I did some workarounds as can be seen in the following commits:
IsraelHikingMap/Site@788a961
to bypass this but I believe the docs should mention the need to remove UseRouting as well so that developers will fix the warning properly without breaking the entire app like I did.
After the removal of UseRouting I believe the app is working as expected (although I'm not very confident it does as I have done some changes I don't fully understand)...

[HarelM]

Nope, I was celebrating too soon...
One of my controllers that doesn't require authentication is not called in my latest code: https://github.com/IsraelHikingMap/Site/tree/32146b91931e6fd3a392413063be3e091685f5ae
Generally speaking, this analyzer brought more damage than good from my point of view, unfortunately... :-(

[captainsafia]

OK, while looking into this, I observed one buggy behavior with the analyzer which is that it will warn on code like:

app.UseEndpoints(e => {});

Which is not desirable since the user might want to be explicitly invoking UseEndpoints with a certain ordering. Marking as a bug to fix this issue.

I'm not using minimal hosting. I'm using top-level statements in program.cs class.

Minimal hosting refers to the use of the WebApplicationBuilder and WebApplication constructs here. You can read more about them here.

I've tried calling MapControllers directly, but it doesn't work at runtime. Angular does not identify the controller endpoint and returns 404.

I'm not a total expert on the SPA templates here but I suspect it might have something to do with the order of the other middlewares in your application. Top-level invocations are working in the built-in Angular templates.

[brunolins16]

I'm not a total expert on the SPA templates here but I suspect it might have something to do with the order of the other middlewares in your application. Top-level invocations are working in the built-in Angular templates.

I believe you are right. I am not expert as well but the call to UseAngularCliServer will configures the UseProxyToSpaDevelopmentServer that will proxy all request to SPA and I believe in this case MapControllers need to be called with UseEndpoints.

Could be related to this discussion: #44244

@javiercn @mkArtakMSFT maybe you could confirm this information.

[captainsafia]

Nope, I was celebrating too soon... One of my controllers that doesn't require authentication is not called in my latest code: https://github.com/IsraelHikingMap/Site/tree/32146b91931e6fd3a392413063be3e091685f5ae Generally speaking, this analyzer brought more damage than good from my point of view, unfortunately... :-(

@HarelM Do you mind opening another issue for your dilemma so we can track if there is a similar problem there? I don't want it to get lost between the comment on the PR and this issue.

[captainsafia]

I split up the analyzer problem into a separate bug.

Moving this to the Blazor area to resolve why the SPA setup used in user code is causing issues with MapControllers.

cc: @mkArtakMSFT

[Nick-Stanton]

@SteveSandersonMS when convenient could you please check this out?

[HarelM]

@captainsafia I'm not sure what the other bug should say if I need to open a new one, the bottom line of this bug describes my problem.
The obsolete message was confusing and somewhat incorrect from my point of view.
I needed a few changes to happen for it to work properly.
I had a middleware after the controllers which causes issues and keeping the useRouting also caused issues.
Hope this helps you guys narrow down the issue. Good luck! :-)

[SteveSandersonMS]

I've looked into it, and it appears to match with what @JamesNK says in #44244. That is, UseSpa is terminal middleware, so if you want other middleware to run for certain URLs, you have to register that other middleware earlier in the pipeline. Calling application.MapControllers() directly (outside UseEndpoints) registers the controller middleware too late, so it isn't compatible with UseSpa. This is not a breaking change - it's always been the case as far as I can tell (verified back to .NET 6 anyway).

@captainsafia Do any problems occur if people call application.UseEndpoints(endpoints => endpoints.MapControllers())? That's compatible with UseSpa but I don't know if it has any drawbacks besides triggering the Roslyn suggestion.

@HarelM You might already be aware, but UseSpa is from Microsoft.AspNetCore.SpaServices.Extensions which is not the latest and recommended way to host a SPA inside ASP.NET Core. As of .NET 6, this was replaced with the Microsoft.AspNetCore.SpaProxy package - read more at https://learn.microsoft.com/en-us/aspnet/core/release-notes/aspnetcore-6.0?view=aspnetcore-7.0#improved-single-page-app-spa-templates. We're not actively working on the older Microsoft.AspNetCore.SpaServices.Extensions package so if possible you'd be better off upgrading, which will implicitly fix the issue you're facing here.