feat(scriptless): compare AKSNodeConfig generated cse cmd with NBC cse cmd

[lilypan26]

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

[Copilot]

Pull request overview

Adds a diagnostic capability to compare env vars derived from an AKSNodeConfig-generated CSE command vs an NBC “phase 2” CSE command, intended to help validate scriptless provisioning parity.

Changes:

• Add compareEnvs to diff env vars between --provision-config and --nbc-cmd, plus a parser for env assignments from an NBC one-liner.
• Adjust Provision selection so NBCCmd execution is skipped when --provision-config is also provided (while still running the comparison).
• Add unit tests for env parsing and env comparison via captured slog output.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
aks-node-controller/app.go	Introduces env diffing/parsing utilities and changes Provision flow when both flags are present.
aks-node-controller/app_test.go	Adds a custom slog handler to capture logs and tests for env parsing + env comparison behavior.

Comments suppressed due to low confidence (1)

aks-node-controller/app.go:427

• When both flags are provided, compareEnvs calls buildCmdFromProvisionConfig, and then Provision calls buildCmdFromProvisionConfig again to actually execute. This duplicates JSON parsing and CSE cmd construction. Consider refactoring so the cmd/env derived during comparison is reused (or compareEnvs accepts the already-built exec.Cmd/env map) to avoid the extra work in diagnostic mode.

	// If both flags are provided, compare environments before proceeding.
	if flags.ProvisionConfig != "" && flags.NBCCmd != "" {
		compareEnvs(ctx, flags, a.getNodeCustomDataPath())
	}

	var cmd *exec.Cmd
	if flags.ProvisionConfig != "" {
		var err error
		cmd, err = buildCmdFromProvisionConfig(ctx, flags.ProvisionConfig)
		if err != nil {

[awesomenix]

You might need to change teh ordering here. We always prefer nbccsecmd first and then use provisionconfig if nbccsecmd is not present

[awesomenix]

might need some kind of error checking/block so any exception or errors here are just gobbled up (so we dont fail provisioning)

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

[Copilot]

compareEnvs calls eventLogger.LogEvent unconditionally. If eventLogger is nil (or becomes nil in future refactors), this panics and relies on the defer/recover to keep provisioning moving, which also logs an error-level "compareEnvs panicked" message. Prefer an explicit nil check (skip event emission when nil) so panics are reserved for truly unexpected failures.

Suggested change

	eventLogger.LogEvent("CompareEnvs", "env vars match between provision-config and nbc-cmd", helpers.EventLevelInformational, now, now)
	} else {
	message := fmt.Sprintf("env var differences (%d): %s", len(diffs), strings.Join(diffs, "; "))
	slog.Info(message)
	eventLogger.LogEvent("CompareEnvs", message, helpers.EventLevelInformational, now, now)
	if eventLogger != nil {
	eventLogger.LogEvent("CompareEnvs", "env vars match between provision-config and nbc-cmd", helpers.EventLevelInformational, now, now)
	}
	} else {
	message := fmt.Sprintf("env var differences (%d): %s", len(diffs), strings.Join(diffs, "; "))
	slog.Info(message)
	if eventLogger != nil {
	eventLogger.LogEvent("CompareEnvs", message, helpers.EventLevelInformational, now, now)
	}

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.