.NET Framework Runtime 4.8 support for Windows Server 2022 removed

[sicil1ano]

Describe the bug

I have a microservice which I cannot migrate to .NET core using .NET Framework.
Until a month ago, the Docker generation phase of my pipeline worked fine, targeting a Windows Server 2022 agent.
I used the generic mcr.microsoft.com/dotnet/framework/runtime:4.8 because I knew from source code there was support for that. It also supported Windows Server LTSC 2016 and 2019.

This Dockerfile has been removed last month with a "consolidate Docker images" commit.
I don't understand what it's been consolidated, except support for different OS versions, like Windows Server LTSC 2022, had been removed. The Dockerfile for .NET Framework 4.8 supporting Windows Server LTSC 2022 has been deleted.
Windows Server 2022 is still a supported OS and its EOL is supposed to be in October 2026.

As a result, my build is failing on my Windows Server 2022 agent because a commit of this repo deleted the Dockefile supporting its OS.

The container operating system does not match the host operating system.

Usually a consolidation is about using the same dependency version, procedures or tools to get the same result.
The commit actually did more than that, it actually removed OS support for .NET Framework versions.

Commit:
7e6e683#diff-a0e488cd1e87cae8ff30848eaf578855494aec2a06135ac92c5e962824f55724

How is that possible to just remove Dockerfiles ensuring different OS version support without causing problems?
I am really frustrated about it, because it is an issue I haven't introduced in my pipeline.

I can see now from the README (https://github.com/microsoft/dotnet-framework-docker/blob/main/README.runtime.md) that I am forced to use mcr.microsoft.com/dotnet/framework/runtime:4.8.1 image to keep supporting Windows Server 2022.
This is not happening for Windows Server 2016 and 2019 Dockefiles. Why is that? Why do I need to upgrade? Why not introducing a brownout period? Why not informing anyone?

Which .NET image(s) are you using?

mcr.microsoft.com/dotnet/framework/runtime:4.8

Steps to reproduce

Use a Dockerfile using mcr.microsoft.com/dotnet/framework/runtime:4.8 and build it on Windows Server 2022 agent.

Other information

No response

Output of docker version

Output of docker info

[lbussell]

Hi @sicil1ano, sorry this was disruptive to your pipelines. We announced the .NET Framework image consolidation four months in advance: #1249

.NET Framework 4.8.1 does not have any breaking changes. See Application compatibility in .NET Framework. If your app works on 4.8 but not 4.8.1, then definitely let us know.

This is not happening for Windows Server 2016 and 2019 Dockefiles. Why is that?

Windows Server 2016 and 2019 don't support .NET Framework 4.8.1, the latest version they support is 4.8: https://learn.microsoft.com/dotnet/framework/get-started/system-requirements#client-operating-systems

I have a microservice which I cannot migrate to .NET core using .NET Framework.

We would definitely like to hear more about what's stopping you from migrating your app to .NET 8+.

[sicil1ano]

Hi @lbussell, thank you for the reply.

I apologise, I don't use GitHub a lot, but you indeed informed people in advance.

Windows Server 2016 and 2019 don't support .NET Framework 4.8.1, the latest version they support is 4.8: https://learn.microsoft.com/dotnet/framework/get-started/system-requirements#client-operating-systems

Thank you, this is clear now.

We would definitely like to hear more about what's stopping you from migrating your app to .NET 8+.

It's not because our API cannot be migrated, but because of requirements we have, we need to use a 3rd-party library that is compiled against .NET Framework 4.8. We don't have a way to change that because it's not under our control.

[sicil1ano]

I adapted my Dockerfile to install .NET Framework 4.8 runtime, as this is a requirement of the 3rd-party library and they cannot guarantee things will be fine with .NET Framework 4.8.1 update.

Thanks for the help.