Fail to open a "Welcome" webpage after clicking "Open in Browser" from "dotnetapp:dev" container context menu

[v-xinda]

OS: Mac&Windows
Docker Extension Build Version: 20230712.5
.NET Version: 8.0.100-preview.5.23303.2

Repro Steps:

1. Create a .NET 8.0 MVC project by command dotnet new mvc --name Dotnetapp -> Open it in VS Code.
2. Make sure the project doesn't have Launch.json file.
3. Make sure the TargetFramework property inside the .csproj file is equal to net8.0.
4. F5 -> Select "Docker: Debug in Container" -> Select "Use .NET SDK" -> Pop up a webpage.
5. Navigate to "Contianers" view -> Right click "dotnetapp:dev" container -> Click "Open in Browser".
6. Check whether succeeds to open a "Welcome" webpage.

Expect:
Succeed to open a "Welcome" webpage.

Actual:
Fail to open a "Welcome" webpage.

[alexyaang]

I'm going to look into this as well.

[alexyaang]

I see what's going on. If you run the .NET SDK build image by right clicking on it in our extension, the ports aren't getting exposed because it's not built in the image. (In other words, the ExposedPort property does not exist in the image because the way a .NET SDK Image is built through dotnet publish). Then if you try to open it in a browser, since there are no ports exposed, browseContainer() can't find any available ports, and thus this issue appears.

[v-xinda]

@alexyaang This issue doesn't reproduce for the cloned "TestSolution" project.
Steps:

1. Open the cloned "TestSolution" project -> Select "Docker: Debug in Container" -> Select "Use .NET SDK" -> Select "TestWebApp" project.
2. Navigate to "Contianers" view -> Right click "testwebapp:dev" container -> Click "Open in Browser".

[alexyaang]

Yeah that makes sense!

[alexyaang]

For the .NET 8.0 MVC project created by command dotnet new mvc --name Dotnetapp, try adding this to the .csproj file

  <ItemGroup>
    <ContainerPort Include="8080" Type="tcp" />
  </ItemGroup>

It should look something like this and see if this issue still persists.

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

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <RootNamespace>dotnet_app</RootNamespace>
  </PropertyGroup>
  
  <ItemGroup>
    <ContainerPort Include="8080" Type="tcp" />
  </ItemGroup>

</Project>

[v-xinda]

@alexyaang This issue still reproduces after adding the <ContainerPort Include="8080" Type="tcp" /> to the .csproj file. The details of the .csproj file as below:

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>
  <ItemGroup>
    <ContainerPort Include="8080" Type="tcp" />
  </ItemGroup>
</Project>

[alexyaang]

mhmm interesting, are you trying this on linux containers or windows containers?

[v-xinda]

@alexyaang I test this on the Linux containers. There is a known issue on Windows containers #4005.