Use FORCE_HOST_GO=y when building Kubernetes

[twz123]

Description

This is to bypass the automatic Go toolchain download which has been added to Kubernetes 1.27 and has been backported to v1.26.3, v1.25.8 and v1.24.12. See kubernetes/kubernetes#115377 for details on that.

This change is only necessary when bumping to the aforementioned Kubernetes versions, but it doesn't hurt to have it in before the version bumps, so this can be backported down to v1.24.

See also: #2879.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

How Has This Been Tested?

• Manual test
• Auto test added

Checklist:

• My code follows the style guidelines of this project
• My commit messages are signed-off
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

[twz123]

Waiting with the version bumps for v1.26.3, v1.25.8 and v1.24.12 until this has been backported to the respective release branches.

[mikhail-sakhnov]

Why don't we want to rely on the auto detection?
Is it because of containerized builds?

[twz123]

Why don't we want to rely on the auto detection?

Not sure what you mean by auto detection. IIUC the build system will try to fetch the Go version via gimme whenever there's a mismatch between the host's Go version and the Go version that Kubernetes wants to be compiled with. This would mean that whenever the k0s build specifies a different Go version than the one that's defined by Kubernetes, the embedded Kubernetes build will disregard that and try to build itself with another Go version instead. Setting FORCE_HOST_GO=y will bypass that logic.

[mikhail-sakhnov]

@twz123 makes sense, thanks for the clarification

[k0s-bot]

Successfully created backport PR for release-1.26:

• [Backport release-1.26] Use FORCE_HOST_GO=y when building Kubernetes #2905