Containers support was moved higher to enable creating image of CLI apps

[MichalPavlik]

Fixes dotnet/sdk-container-builds#513

[MichalPavlik]

@baronfel, we have CheckContainersPackage target checking Microsoft.NET.Build.Containers package presence. Should I move it too? This check is for users using nuget package which supported only web apps.

[baronfel]

I think we need to remove EnableSdkContainerSupport from these conditions, and instead put that condition on the PublishContainer target directly - this will enable someone to call -t:PublishContainer at the solution level and have the target be available (but not enabled) for all projects.

[MichalPavlik]

Okay, I wanted to avoid importing these files when publishing is not required.

[baronfel]

Here's an example of a scenario that should become possible after we move the Container targets into the base SDK:

• myapp.sln
  • myapp.lib.csproj
  • myapp.web.csproj (references myapp.lib)
  • myapp.cli.csproj (references myapp.lib, has manually set EnableSdkContainerSupport to true)
  • myapp.tests.csproj (references myapp.lib)

We should be able to run dotnet publish -t:PublishContainer on myapp.sln and get containers generated for myapp.web and myapp.cli as a result.

[baronfel]

@MichalPavlik once we merge this we'll need to backport to release/8.0.2xx.

[baronfel]

This looks correct and great to me - I'd like some level of scenario test to show folks that it does work, and then after merge I can look at updating docs and other resources to talk about the property.

[baronfel]

With the addition of the test showing how it all works, I'm very happy to approve this PR! Thanks for plumbing it through @MichalPavlik!

[baronfel]

/backport to release/8.0.2xx

[github-actions]

Started backporting to release/8.0.2xx: https://github.com/dotnet/sdk/actions/runs/7103894377