[NXOS] Fix interface reconciliation loop

[nikatza]

No description provided.

[felix-kaestner]

Thanks for this fix!

Could you add a little description when you merge why this change was done, i.e. that we currently update the configuration in YANG on every reconcile as we missed the default value of this field?

[github-actions]

Merging this branch will not change overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/ironcore-dev/network-operator/internal/provider/cisco/nxos	10.67% (-0.00%)	👎

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Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/ironcore-dev/network-operator/internal/provider/cisco/nxos/intf.go	17.81% (-0.12%)	146 (+1)	26	120 (+1)	👎

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/ironcore-dev/network-operator/internal/provider/cisco/nxos/intf_test.go

[nikatza]

Pysical interfaces are currently being continuosly reconciled because we
miss one of the default values. This happens because the method
EnsureInterface() calls Default() to initialize PhysIf structs. The
Default() method did not set FecMode, leaving it as empty string. This
caused a mismatch: the controller expected empty string while NX-OS
devices default to "auto". During reconciliation, GetConfig() would read
"auto" from the device but the desired config had "", triggering an
update. As NX-OS kept returning "auto", we got into an infinite
reconciliation loop. Fixed by initializing FecMode to FecModeAuto in
Default() to match the NX-OS default.