Add kernel parameter reporting to hypervisor status

[anokfireball]

This enables the operator to report kernel boot parameters in the Hypervisor status, allowing users to verify kernel configuration across the fleet.

[notandy]

Pretty sure systemd provides kernel commandline via DBUS

[fwiesel]

I do not think it is a good idea to block this change based on that. The /proc/cmdline is world-readable, it really can't get much easier and robust than reading that file.

[notandy]

I do not think it is a good idea to block this change based on that. The /proc/cmdline is world-readable, it really can't get much easier and robust than reading that file.

I don't think we agree on this.

Anyway, I couldn't find a method or property in default DBUS services that exposes the cmdline. Also proc/cmdline seems to be mounted by default in every container, so this pr just needs an rebase.

[github-actions]

Merging this branch will increase overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/cobaltcore-dev/kvm-node-agent/internal/controller	41.28% (+1.52%)	👍
github.com/cobaltcore-dev/kvm-node-agent/internal/kernel	94.74% (+94.74%)	🌟

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Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/cobaltcore-dev/kvm-node-agent/internal/controller/hypervisor_controller.go	59.17% (+1.27%)	120 (+6)	71 (+5)	49 (+1)	👍
github.com/cobaltcore-dev/kvm-node-agent/internal/kernel/interface_mock.go	91.67% (+91.67%)	12 (+12)	11 (+11)	1 (+1)	🌟
github.com/cobaltcore-dev/kvm-node-agent/internal/kernel/parameters.go	100.00% (+100.00%)	7 (+7)	7 (+7)	0	🌟

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.

Changed unit test files

• github.com/cobaltcore-dev/kvm-node-agent/internal/controller/hypervisor_controller_test.go
• github.com/cobaltcore-dev/kvm-node-agent/internal/kernel/parameters_test.go