Support for MAUI runtimes in ASP.NET Core?

JustArchi commented 2 years ago

Hey,

I apologize in advance if this is not the correct place to ask this, but I didn't find any better one. Feel free to move this issue if appropriate.

For testing purposes, in MAUI net6.0-android project I've tried to reference other project of mine targetting net6.0 which is a library. I didn't have any issues doing so, but during compilation I've stumbled upon following error:

Error NETSDK1082 There is no Microsoft.AspNetCore.App runtime package available for the specified RuntimeIdentifier "android-x86"

If I understand this right, I can reference standard net6.0 projects because Microsoft.NETCore.App.Runtime.Mono.android-x86 exists and is usable, at least I successfully did that with example net6.0 library. However, I'd like to reference a library that has actual ASP.NET Core elements (Kestrel web server, API with MVC etc), which according to the error is impossible because it can't find a required android-x86 runtime, which seems to be correct as of today.

Now I apologize if I'm trying to do some extreme stupidity, or I don't understand something, but I wanted to verify whether it'd be possible to "convert" existing CLI project of mine which uses Kestrel and API controllers into an Android MAUI app that could start the "backend" part on the target machine, with some nice frontend utilizing those API endpoints over HTTP. I'm testing this in .NET 6.0 preview 6 if it matters.

Is this possible/planned? Or perhaps I'm doing something horribly wrong?

In any case, thank you in advance for answering, I appreciate it.

Eilon commented 2 years ago

(Transferring back to aspnetcore repo...)

Hi @JustArchi , code that is specific to ASP.NET Core scenarios, such as hosting Kestrel, requires platform support, which as you discovered, it not available on some platforms, such as Android.

I think this might really be a question for the ASP.NET folks as to whether there is a desire to support certain features, such as Kestrel, on "arbitrary" platforms, or whether to specifically add support to particular platforms (e.g. android-x86).

Hosting a local web server in a cross-platform app is something reasonable (though perhaps not super common), so it's worth considering.

For right now I'm not aware of any plan to support this.

Eilon commented 2 years ago

Tagging @danroth27 because I think you mentioned something about this the other day.

JustArchi commented 2 years ago

Thanks for your answer @Eilon, I appreciate it.

Hosting a local web server in a cross-platform app is something reasonable (though perhaps not super common), so it's worth considering.

Yeah I definitely don't see everybody jumping on this idea right away and bundling every Android/iOS/etc app with a local web server, but I also came to conclusion that it's something reasonable enough to at least suggest/evaluate on. I have no idea how much work would be required to bring ASP.NET Core runtime to those new .NET 6.0 platforms, but if it helps in any way then I'd be definitely interested in making use of such functionality, at least for that one use case I have in mind.

It could also be a decent alternative if somebody wanted to build an app that looks more like a typical website to you. To give you some idea, I have a CLI app realizing its functionality with bundled Kestrel web server and MVC APIs, which is not really any different from a typical ASP.NET Core website, but it's more of the CLI app and APIs are just an extra. Anyway, I bundle that app with frontend written in html/css/js (static files that Kestrel serves), which results in user navigating to his localhost app address, where he can control the app through a website interface (that calls appropriate API endpoints).

As an experiment I tried to convert this "idea" into Android app, where the app could create a very simple Webview with that localhost address (where the frontend is already mobile-aware), while launching the backend part the same as on all other OSes I build this for. This in result failed as of today, since there is no ASP.NET Core runtime for Android (which is just an example platform I tried to test it on).

I'm describing that just to give you some insight into what this whole "feature request" could be useful for, while MAUI is great on its own and building new apps is definitely going to be interesting, there might be more of such CLI apps with some kind of web interface that could easily be converted into Android apps without much hassle if just the ASP.NET Core runtime was available to make use of. It's not like my app requires something more than a web server with static files and MVC APIs anyway.

In any case thank you in advance for evaluation of this idea, perhaps it could be something to think of for the future.

mkArtakMSFT commented 2 years ago

@davidfowl feel free to update the label. This seems to be the closest match.

juwens commented 2 years ago

@JustArchi to second your "reasonable scenario" statement.

We are actually started using local GRPC (client and server) in our current Xamarin app as an IPC technology to communicate between two apps.

We have some LOB-concerns which forces us to do a lot (and kinda complex) local IPC between our app and a third party app.

And to use one identical API technology on all Platforms targets (Android, iOS and Windows) we've chosen grpc.

eestein commented 2 years ago

I've got the "same" problem. I'm trying to add DI to my maui app using the idea James wrote here https://montemagno.com/add-asp-net-cores-dependency-injection-into-xamarin-apps-with-hostbuilder/ And then I get the error:

NETSDK1082 There was no runtime pack for Microsoft.AspNetCore.App available for the specified RuntimeIdentifier 'iossimulator-x64'.
Sample.Mobile.Maui
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Sdk.FrameworkReferenceResolution.targets 427

The same goes for maccatalyst-x64, android-x86 and linux-arm.

I created a mauilib with the default structure:

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <TargetFrameworks>net6.0-ios;net6.0-android;net6.0-maccatalyst</TargetFrameworks>
        <!-- <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('windows')) and '$(MSBuildRuntimeType)' == 'Full'">$(TargetFrameworks);net6.0-windows10.0.19041</TargetFrameworks> -->
        <TargetPlatformMinVersion Condition="$(TargetFramework.Contains('-windows'))">10.0.17763.0</TargetPlatformMinVersion>
        <UseMaui>true</UseMaui>
        <SingleProject>true</SingleProject>

        <SupportedOSPlatformVersion Condition="'$(TargetFramework)' == 'net6.0-ios'">14.2</SupportedOSPlatformVersion>
        <SupportedOSPlatformVersion Condition="'$(TargetFramework)' == 'net6.0-maccatalyst'">14.0</SupportedOSPlatformVersion>
        <SupportedOSPlatformVersion Condition="'$(TargetFramework)' == 'net6.0-android'">21.0</SupportedOSPlatformVersion>
        <SupportedOSPlatformVersion Condition="$(TargetFramework.Contains('-windows'))">10.0.18362.0</SupportedOSPlatformVersion>
    </PropertyGroup>

    <ItemGroup>
      <Folder Include="Platforms\iOS\" />
      <Folder Include="Platforms\Windows\" />
      <Folder Include="Resources\Fonts\" />
      <Folder Include="Resources\Images\" />
    </ItemGroup>

</Project>

I tried recreating the projects twice from the command line, but it still won't work. dotnet new maui and dotnet new mauilib.

Is there a workaround for this? I'd very much like to be able to use DI, but I'm blocked as is.

Checking up the nuget repository, I found the references, but for .Mono. Is there something I'm doing incorrectly?

danroth27 commented 2 years ago

@eestein .NET MAUI already has support for dependency injection built-in. MauiAppBuilder exposes a Services property that you can use to configure your services. You shouldn't need to add any additional dependencies.

eestein commented 2 years ago

@danroth27 thanks, I appreciate you taking the time to evaluate my question. The thing is, I'm not adding anything extra.

This is the info for my maui lib.

These are my usings:

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Maui.Hosting;

These are the only nuget packages I've got installed:

These are the dependencies:

This is my csproj:

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <TargetFrameworks>net6.0;net6.0-ios;net6.0-android;net6.0-maccatalyst</TargetFrameworks>
        <Nullable>enable</Nullable>
        <UseMaui>true</UseMaui>
        <SingleProject>true</SingleProject>

        <SupportedOSPlatformVersion Condition="'$(TargetFramework)' == 'net6.0-ios'">14.2</SupportedOSPlatformVersion>
        <SupportedOSPlatformVersion Condition="'$(TargetFramework)' == 'net6.0-maccatalyst'">14.0</SupportedOSPlatformVersion>
        <SupportedOSPlatformVersion Condition="'$(TargetFramework)' == 'net6.0-android'">21.0</SupportedOSPlatformVersion>
        <SupportedOSPlatformVersion Condition="$(TargetFramework.Contains('-windows'))">10.0.18362.0</SupportedOSPlatformVersion>
    </PropertyGroup>

    <ItemGroup>
        <ProjectReference Include="..\Sample.Data\Sample.Data.csproj" />
    </ItemGroup>

</Project>

And I still get the error:

/usr/local/share/dotnet/sdk/6.0.100-rc.2.21505.57/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.Sdk.FrameworkReferenceResolution.targets(427,5): error NETSDK1082: There was no runtime pack for Microsoft.AspNetCore.App available for the specified RuntimeIdentifier 'iossimulator-x64'. [/Users/eestein/Documents/dev/smp/sample-repo/Sample/Sample.Mobile.Maui/Sample.Mobile.Maui.csproj]

I'm not trying to waste anyone's time here, believe me when I tell you I research a lot before asking. The thing is I'm stuck on this one since yesterday. Before trying many things I found online I recreated the projects twice and they still won't work. I tried recreating from VS2022 and also from the command line on my macOS. I still get the error when I reference my mauilib from the maui app.

davidfowl commented 2 years ago

Why did you include ASP.NET Core if you're only trying to use dependency injection?

eestein commented 2 years ago

@davidfowl I didn't... I just created the maui lib using the provided template. And, I also tried removing that framework, I just couldn't find a way to do so.

I do need to use HttpClient, though

Eilon commented 2 years ago

@eestein is that the CSPROJ of the project that's failing, /Users/eestein/Documents/dev/smp/sample-repo/Sample/Sample.Mobile.Maui/Sample.Mobile.Maui.csproj? Is there any other .targets or .props file or a global.json that might be affecting things?

eestein commented 2 years ago

@Eilon let me take a closer look and I'll get back to you on that. Thanks.

I'm also looking for specific packages that could be adding the FW.

davidfowl commented 2 years ago

Maybe it's the SampleData project reference?

Eilon commented 2 years ago

A plain dotnet new mauilib should not reference AspNetCore in any way, so something else is bringing it in.

eestein commented 2 years ago

Thank you, gentlemen! @davidfowl your comment made me realize there was one specific thing I hadn't tracked. The problem was that one of the libs had a reference to FluentValidations.AspNetCore instead of FluentValidations. That's what was loading the aspnetcore FW.

I'm sorry to have wasted your time. But I also think, if possible, a better error message could be provided. If in the message we could see the offending library, that would help a lot!

Thank you all, @danroth27 , @Eilon and @davidfowl

Please consider my suggestion for the error message.

juwens commented 2 years ago

Come on guys and gals, GRPC is THE strongly advertised tech from MS for IPC and SOA. You really need to bring asp.net to Net 6 (Xamarin) iOS and Android Runtimes.

In the end, that was the promise MS made, one runtime for all Platforms, not: your lib might only run on one or two Net 6 runtimes (bot not on ios or android or uwp).

Today we can still use the "Grpc.Core" Server wich works without asp.net, but this will be deprecated in the near future.

rpc-dotnet (the Grpc.Net.Client and Grpc.AspNetCore.Server nuget packages) is now the recommended gRPC 
implementation for .NET/C#. The original gRPC C# implementation (the Grpc.Core nuget package)

https://grpc.io/blog/grpc-csharp-future/

ramondeklein commented 2 years ago

I am quite confused why this is still not supported. I already use the Kestrel webservice in my Xamarin app for a while. It seems that Microsoft.AspNetCore (v2.2.0) works fine in Xamarin and probably will work in MAUI too. Later versions don't work anymore, because they are not available as separate packages. I never understood why an application that exposes a web-service should be treated so special (I don't know of any other language that does this). ASP.NET core was just a bunch of packages with .NET core v2.2 and it worked fine.

I tested it with iOS, Android and UWP applications without any issues. I was hoping that MAUI and .NET 6 would really bring us one .NET.

danroth27 commented 2 years ago

Hi folks. I'd like to collect some more details on the specific scenarios for using ASP.NET Core in a mobile app. So far from the feedback in this issue I've identified two scenarios:

Building a mobile app as a locally hosted web app (https://github.com/dotnet/aspnetcore/issues/35077#issue-962146241)
IPC between apps using gRPC (https://github.com/dotnet/aspnetcore/issues/35077#issuecomment-908238983)

Anything else?

juwens commented 2 years ago

@danroth27 thanks for taking a look into this.

Additional to #35077 there is local network GRPC planned. For example:

GRPC call from a smartwatch to mobile-phone
GRPC call from a pc to a mobile phone

tl/dr:

case "smartwatch -> mobile" : ad-hoc controlling the app temporarily, when you need your hands and cannot hold the mobile phone at the moment; afterwards continuing on the phone
case "pc -> mobile phone": use the convenience of a keyboard and big screen to enter data and review the result of the data collected with the mobile phone

It all boils down to one person continuously switching between 3 devices (mobile phone, pc, smartwatch) to do its work. Functionality/state which is held on one "main" device (usually mobile phone), and depending the circumstances is controlled by phone itself, smartwatch, pc.

Usually you would do that with a central server/could service holding the state/functionality. For privacy and ease of configuration reasons, we are bound to the solution of no-server/cloud solution, where the "main" device holds the state.

nextfool commented 2 years ago

Hi folks. I'd like to collect some more details on the specific scenarios for using ASP.NET Core in a mobile app. So far from the feedback in this issue I've identified two scenarios:

Building a mobile app as a locally hosted web app (Support for MAUI runtimes in ASP.NET Core? #35077 (comment))

IPC between apps using gRPC (Support for MAUI runtimes in ASP.NET Core? #35077 (comment))

Anything else?

This absolutely wonderful, thinking about a fully functioning backend web server (restful api, gRPC, signalR, database etc.) working with WebView, this gonna change the way people build mobile apps!!!

Really looking forward to this.

dougbu commented 2 years ago

Putting this on the @dotnet/aspnet-blazor-eng radar. This is not really a general area-infrastructure issue.

ramondeklein commented 2 years ago

@dougbu I’m not sure why this is marked a Blazor issue. It has nothing to do with Blazor. When you read my comment from December 7, then I try to explain that it is a fundamental .NET issue, because Kestrel isn’t an ordinary package anymore, but considered a “platform”. It”s not a real MAUI issue, but a fundamental ASP.NET issue.

We implemented a Kestrel based webserver (using ancient Kestrel package from the .NET Core 2.2 era) and have an Angular client on top of it. It works great, but not being able to upgrade Kestrel is not a sustainable solution.

javiercn commented 2 years ago

This is area-runtime as it is about being able to use <FrameworkReference Include="Microsoft.AspNetCore.App" /> within a Maui application.

dougbu commented 2 years ago

Thanks @ramondeklein and @javiercn for clearing up my confusion

davidfowl commented 2 years ago

I'm actually not sure this belongs in runtime 😄

javiercn commented 2 years ago

@davidfowl well... it's about kestrel... 😄

Difference commented 2 years ago

Hi folks. I'd like to collect some more details on the specific scenarios for using ASP.NET Core in a mobile app. So far from the feedback in this issue I've identified two scenarios:

@danroth27 Thank you very much for giving this attention. I've run into this in these scenarios:

1) I've made a controlpanel for starting, stopping, setting port, getting messages etc. for a local webserver made with Kestrel and Minimal api in MAUI. I was hoping that it would be cross platform, so I could use it on Mac Desktop, but using Sdk="Microsoft.NET.Sdk.Web" tells me that this is a no go on Catalyst becasue of There was no runtime pack for Microsoft.AspNetCore.App available for the specified RuntimeIdentifier 'maccatalyst-x64' The usecase here is "Make a crossplatform (local) server with GUI control"

2) I tried to build my Controlpanel+server in Blazor WASM, but got a similar error. The usecase here is "Build and distribute an API that can run on client computer without install"

3) Quite a few IOS apps use local servers for sharing files with desktop computers on the same network. It's a really simple and nice way to share data. The usecase here is "Share data from App on local network via http"

4) Expose a "Control panel" for a mobile app. Start/stop/Record/Pause/Take photo etc. The usecase here is "Expose a web GUI interface on the local network to control an app"

Difference commented 2 years ago

@davidfowl wrote

I'm actually not sure this belongs in runtime 😄

If this means making Kestrel usable without the breaking dependencies , +1000 thums up :-)

gingters commented 2 years ago

@danroth27 For us the requirement would be to wrap an SPA that talks to an backend together with that backend into a desktop application. On Windows that is not a problem, but this application should also work on a Mac, so MacCatalyst should be supported.

The embedded backend should be able to provide http Endpoints for the SPA running in a MAUI Webview, so that the SPA app can access the local backend, as well as provide support for EF Core so that the standalone desktop version can connect to a database (which would require to open a TCP connection, which also does not work on the iOS-App-wrapped-in-catalyst at the moment.

For the moment Windows and Mac-Desktop are the main targets, Linux would be awesome. Mobile (iOS / Android) not so much.

Plan B would be to use an electron host that could launch the API as another process, but when we are not within the same application it's way more complicated to TLS the api access without running into several self-signed certificate issues.

SteveSandersonMS commented 2 years ago

Exposing a real TCP listener in your app can be problematic for multiple reasons (listeners may be blocked by local firewall-type tools, and it's difficult to be sure that you're not processing requests from unsanctioned 3rd-party processes running on the same machine). If at all possible I'd recommend setting up a different, non-HTTP communication channel from your JS code to the hosting .NET application. That's how BlazorWebView works, and can be achieved using the web view's JS interop APIs.

gingters commented 2 years ago

Exposing a real TCP listener in your app can be problematic for multiple reasons (listeners may be blocked by local firewall-type tools, and it's difficult to be sure that you're not processing requests from unsanctioned 3rd-party processes running on the same machine). If at all possible I'd recommend setting up a different, non-HTTP communication channel from your JS code to the hosting .NET application. That's how BlazorWebView works, and can be achieved using the web view's JS interop APIs.

The idea is to take a currently existing and cloud-hosted App-environment (SPA and corresponding API) and package that together as a standalone Desktop app, that should be able to run on deliberately non-connected computers (yes, these still do exist). And no, there are no unsanctioned processes on that machine, for sure ;)

Let's just for a moment assume that it would be feasible to monkeypatch the fetch / http APIs in the browser to redirect all of the http requests the SPA does, through a JS interop API. Then the next big problem would be to replace the inner workings of the API part to receive the interop calls, create a fake request and then somehow dispatch that through to the hundreds of controller actions which are called.

But to achieve that, we would still need to be able to compile the existing code of the system, especially the controllers, the DI system, the SignalR Hub from ASP.NET Core and everything else including the EF Core part of the API against Mac Catalyst, to even try to achieve to replace all the inner workings. That would still require ASP.NET Core to support the MAUI runtimes (at least MacCatalyst).

Electron would make this possible, but the client would be way more happy if it was a pure .NET solution.

czmirek commented 2 years ago

Hi folks. I'd like to collect some more details on the specific scenarios for using ASP.NET Core in a mobile app. So far from the feedback in this issue I've identified two scenarios:
* Building a mobile app as a locally hosted web app ([Support for MAUI runtimes in ASP.NET Core? #35077 (comment)](https://github.com/dotnet/aspnetcore/issues/35077#issue-962146241))

* IPC between apps using gRPC ([Support for MAUI runtimes in ASP.NET Core? #35077 (comment)](https://github.com/dotnet/aspnetcore/issues/35077#issuecomment-908238983))
Anything else?

I think I have a very simple use-case, much simpler than others in this thread. I don't need to run Kestrel at all.

I want to have one application code base but with two deployments:

to a mobile app (Android)
to a website

But since Blazor Hybrid cannot be deployed as a website, I tried to create 3 projects:

Blazor Server-Side app (Web)
MAUI Blazor Hybrid (Android)
Shared library containing razor pages and components

I can connect Web to the shared library....but this has to be a "Razor Class Library" which references Microsoft.AspNetCore.App.

Connecting the Android project with shared library works but it won't build because of the error mentioned in the first post.

danroth27 commented 2 years ago

I can connect Web to the shared library....but this has to be a "Razor Class Library" which references Microsoft.AspNetCore.App.

@czmirek A Razor Class Library should only reference Microsoft.AspNetCore.App if it's setup to contain MVC Views or Razor Pages (.cshtml files). If your Razor Class Library only contains Blazor components, then it doesn't need to reference Microsoft.AspNetCore.App.

When you create the Razor Class Library, make sure the "Support pages and views" option is not checked:

The project file for the Razor Class Library should look something like this (no FrameworkReference):

<Project Sdk="Microsoft.NET.Sdk.Razor">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <SupportedPlatform Include="browser" />
  </ItemGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Components.Web" Version="6.0.2" />
  </ItemGroup>

</Project>

Falco20019 commented 2 years ago

Just wanted to leave a +1 on gRPC with Android.

We have a framework in place which we use with monoandroid + netcoreapp3.1 + netstandard2.1. All modules either use gRPC as client or offer one or more services through gRPC. Everything runs using Grpc.Core which is EOL in just 3 months. So we are not very comfortable to not have any way forward right now... And we heavily invested into gRPC by also using xDS (client + server), interceptors for AuthN + AuthZ, building our tracing and logging stacks on top of it, and built our whole environment around it.

We use it for IPC on the device between modules, but also for communication with other devices and the warehouse control system (intralogistics). All connected through a central xDS server with custom dynamic service management, where the management is also done through gRPC. We use lots of bi-directional streaming too, like for observers and events.

We had hoped that the unification of .NET 6 would resolve that issue before the EOL. So I would really love to see that this gets some attention, since it doesn't seem to be an so unusual use-case anymore.

LukeTOBrien commented 2 years ago

Hello. I would just like to add my use case to your discussion.
I am working on an online web app that creates HTML presentations, similar to RevealJS.
I would like to create an offline app using MAUI but ideally I don't want to run the HTML file from the file system, ideally I want to spin up a web server and then copy the files there.
The HTML presentation and asset files (images, etc) are in a zip for offline viewing, so the MAUI app would spin up a server, unzip/deploy the files to that server then display the index.html in a WebView.

My use case is not exactly what you are talking about, I don't need a ASP server, just a plain old web server.

Catter38 commented 2 years ago

Hi. I also ran into this issue. Not because I actually wanted to spin up a webserver, but because I use a shared project which includes all the request/response models for my API. I use StronglyTypedId for my models, which automatically generates the required structs and converters. It also generates a ValueConverter for EntityFrameworkCore and because of this, Microsoft.NETCore.App gets referenced. I know that maybe this is an edgecase, but it's still a big problem, because the only option I have right now, is to not use StronglyTypedId, otherwise I'm not able to reference the shared project.

AigioL commented 2 years ago

Hi. I have created a sample project that ASP.NET Core 2.2 works fine on Xamarin.Android 12 and net6.0-android. I think since the old version of 2.2 works fine, the new version of 6.0 shouldn't be too difficult to run, but at the moment the SDK is blocking the reference.

this is the compiled APK package

net6-Signed.apk

XamarinAndroid12-Signed.apk

https://github.com/BeyondDimension/AspNetCore.Mobile/tree/net6.0-android_with_asp.net_core_2.2

Also in this example the WebHost is hosted on the activity, it would be better to host it in the Foreground Services

Eilon commented 2 years ago

@AigioL yup, this pattern may very well have worked in older versions of ASP.NET Core because back then a lot of the code was in regular NuGet packages and didn't use a "runtime". In the "runtime" model many NuGet packages contain just API definitions (if at all), but all the implementation is in a "runtime" that is platform-specific. But in more recent versions of ASP.NET Core, the "runtime" is used for a lot more features, meaning that if you don't have a compatible runtime for the platform you're running, you have no code to run.

argarcia-ottersoft commented 2 years ago

Any update on this? I would like to run a Kestrel server on an iOS device using MAUI, I was able to do this on Xamarin.

jormenjanssen commented 2 years ago

Exposing a real TCP listener in your app can be problematic for multiple reasons (listeners may be blocked by local firewall-type tools, and it's difficult to be sure that you're not processing requests from unsanctioned 3rd-party processes running on the same machine). If at all possible I'd recommend setting up a different, non-HTTP communication channel from your JS code to the hosting .NET application. That's how BlazorWebView works, and can be achieved using the web view's JS interop APIs.

Exposing a http listener / tcp listener is no problem at all we're doing this currently with our Xamarin solution. Mobile os'es like Android and IOS are working out of the box with the solution below. For your third party concern it's easy to fix this by simply adding an authentication header on a custom Webview renderer. I think the solution with JS interop is a lot hackier way to run a real world React application with websockets and ajax requests.

private static Uri GetFreeListenerEndPoint()
{
            var l = new TcpListener(IPAddress.Loopback, 0);
            l.Start();
            var ep = (IPEndPoint)l.LocalEndpoint;
            l.Stop();

            return new Uri($"http://{ep.Address}:{ep.Port}/");
}

isaacrlevin commented 2 years ago

Interesting thread, and I thought I would put my use case in here.

I have an app called PresenceLight, which is currently a .NET 6 WPF app that broadcasts Teams presence to smart lights and as part of that app, I have to do an OAuth dance to register access of PresenceLight to a user's LIFX Cloud account. I am currently doing this by spinning up a Kestrel server that runs during the token retrieval process. Here is the code that does that

https://github.com/isaacrlevin/presencelight/blob/083e92bd5245f10cb613fa3025f4d964cea1a5a4/src/PresenceLight.Core/Lights/LifxServices/LIFXOAuthHelper.cs#L38

I see this sort of experience is not available currently in MAUI because of lack of MAUI runtime support for ASP.NET Core. I know there are alternative workarounds, but would love if the same experience I have building an app in WPF would just work in MAUI.

keesschollaart81 commented 2 years ago

Interesting thread indeed, just to add to the examples on why it would be great to be able to run ASP.NET Core 6 with (in my case) net6.0-android...

We're building an app for azena.com, an Android based OS for AI-cameras. To be able to expose HTTP API's, they host the webserver and we get a RPC-like callback with an 'AzenHttpRequest' (including a request-stream, method, etc.) that must be returned with an 'AzenaHttpResponse'. We already have a lot of ApiControlers/routes that we host on other platforms and want to re-use. We were able to bring IServer, IFeatureCollection and all to life, but only in the aspnetcore 2.2. It would be great if somehow this was possible with individual packages or if the net6+ generation of the runtime got compatible with net6.0-android.

ramondeklein commented 2 years ago

Exposing a http listener / tcp listener is no problem at all we're doing this currently with our Xamarin solution. Mobile os'es like Android and IOS are working out of the box with the solution below. For your third party concern it's easy to fix this by simply adding an authentication header on a custom Webview renderer.

A TCP listener is not an HTTP server. Even the HTTP listener is a very basic primitive compared to Kestrel that has much more features. One of the downsides of the HTTP listener is that it doesn't support request cancellation, which makes it difficult to implement an event-source handler. With Kestrel the event-source is alive as long as the HTTP request isn't cancelled. Also Kestrel has a much broader ecosystem and supports all kinds of middleware that can be useful for authentication, caching, rate-limiting, ... Implementing this manually is a source of bugs and potential security issues.

Choosing a base SDK that targets either ASP.NET Core, MAUI, WPF, ... is nice as a convenience feature, but it shouldn't dictate the possible combinations. I don't understand why you can't combine Kestrel / ASP.NET Core with WPF and/or MAUI. Every article describing MAUI speaks about "one .NET", but it's simply not true. There is no one .NET. You still need Mono for some projects and you can't even combine libraries within a single architecture.

Eilon commented 2 years ago

I don't understand why you can't combine Kestrel / ASP.NET Core with WPF and/or MAUI

It's a feature request that hasn't been implemented, that's why.

ramondeklein commented 2 years ago

I don't understand why you can't combine Kestrel / ASP.NET Core with WPF and/or MAUI

It's a feature request that hasn't been implemented, that's why.

Real constructive argument... Why is combining libraries considered a feature? Why not just add the Kestrel assemblies and the MAUI or WPF assemblies in one executable? It worked that way up to .NET Core v2.0, but MS decided to make things "easier" by providing additional frameworks that are not interoperable...

davidfowl commented 2 years ago

@ramondeklein we know the feature is important, we have a list of scenarios, it hasn't been prioritized amongst the 7.0 work, we haven't closed on the plan here as yet, and we'll update the issue when we do.

juwens commented 2 years ago

@davidfowl what’s your suggested workaround in the meanwhile?

Googles grpc Server paket was deprecated a year ago in favor for the MS grpc Server, will Google’s Paket work under MAUI?

We have an existing Xamarin project with grpc. Should we:

A: wait two years and keep using Xamarin, which is already badly supported today?
B: switch our project to MAUI, and hope the deprecated Google grpc server will work under Maui for the next two years?
C: abandon the highly by MS advertised technology GRPC and use another API technology, like 0MQ or MQTT?

davidfowl commented 2 years ago

The most short term thing you can do to get an Http server going would be to use HttpListener.

juwens commented 2 years ago

The most short term thing you can do to get an Http server going would be to use HttpListener.

Sadly that doesn’t answer the question. I don’t see how that would work with the MS GRPC Server which uses HTTP/2. Could you please elaborate a little and try to provide an actual workaround for us to use GRPC server in the next (at least) two years.

Falco20019 commented 2 years ago

According to https://groups.google.com/g/grpc-io/c/OTj5mb1qzb0 we can at least use the old Grpc.Core for one more year until we run into the end-of-life issues again. The new lib sadly does still not really work on the Xamarin stack (while the old did). Sadly, @jtattermusch also mentioned there, that support for Xamarin and Unity will most likely be dropped. That's a huge bummer for us, since it basically means, we now have a whole product and framework build on top of a dying horse without real alternative.

dotnet / aspnetcore

Support for MAUI runtimes in ASP.NET Core? #35077