When enabled, Spark's Kubernetes knob provider makes targeted wallet freezes live-updatable, selective, and reversible

What the evidence shows

Technical and product details

1. Documented behavior

   Operator startup creates the Kubernetes knob provider only when knob configuration is enabled. That provider watches its ConfigMap and updates internal knob values in real time. 13

   Supporting material shown on this page

   live ConfigMap watcherPinned source code · github.com · checked 2026-07-14

   74// Behavior:
   75// 1. Attempts to get Kubernetes configuration (uses in-cluster config, no kubeconfig fallback)
   76// 2. Creates a Kubernetes clientset for API communication
   77// 3. Sets up a ConfigMap informer with custom ListerWatcher to avoid LIST permission requirement
   78// 4. Configures event handlers for ConfigMap add/update events
   79// 5. Starts the informer goroutine and waits for initial cache sync
   80//

   conditional Operator initializationPinned source code · github.com · checked 2026-07-14

   445	var valuesProvider knobs.KnobsValuesProvider
   446	if config.Knobs.IsEnabled() {
   447		if provider, err := knobs.NewKnobsK8ValuesProvider(errCtx, config.Knobs.Namespace); err != nil {
   448			// Knobs has failed to fetch the config, so the controllers will rely on the default values.
   449			logger.Error("Failed to create K8 knobs", zap.Error(err))

2. Documented behavior

   The integration test freezes Wallet A while its reads still work, leaves Wallet B unaffected, then restores Wallet A by clearing the value. 2

   Supporting material shown on this page

   targeting and reversal testPinned source code · github.com · checked 2026-07-14

   24//   - Clearing the knob restores walletA's ability to mutate state.
   25//
   26// This test requires the minikube environment (it talks to a real knob
   27// ConfigMap and live SOs). It is skipped automatically when the knob
   28// controller is unavailable.
   29func TestWalletKillSwitch_BlocksMutationsAllowsReads(t *testing.T) {
   30	kc, err := sparktesting.NewKnobController(t)

Scope control

What this does not establish

• This proves the implementation and its integration-test behavior, not that production Operators enable the Kubernetes provider, who holds production RBAC, or whether Lightspark can modify Breez's or Flashnet's configuration. 123

Sources and excerpts

Primary sources

The relevant details and available source-code excerpts appear alongside the claims above. This list preserves the complete original-source trail for independent verification.