plugin: Remove vmStore from AutoscaleEnforcer

After the changes from #865 that switched to fetching VmInfo from Pod
objects, the VM store is no longer needed long-term, just during initial
cluster state reading (which can *also* be swapped out) and for event
generation.

This commit changes the VM store from being stored in the
AutoscaleEnforcer struct to being passed in to readClusterState as an
argument.

pkg/plugin/plugin.go

@@ -33,13 +33,8 @@ type AutoscaleEnforcer struct {
 	state    pluginState
 	metrics  PromMetrics
 
-	// vmStore provides access the current-ish state of VMs in the cluster. If something's missing,
-	// it can be updated with Resync().
-	//
-	// Keeping this store allows us to make sure that our event handling is never out-of-sync
-	// because all the information is coming from the same source.
-	vmStore IndexedVMStore
-	// nodeStore is doing roughly the same thing as with vmStore, but for Nodes.
+	// nodeStore provides access to the current-ish state of Nodes in the cluster. If something's
+	// missing, it can be updated with Relist().
 	nodeStore IndexedNodeStore
 }
 
@@ -99,7 +94,6 @@ func makeAutoscaleEnforcerPlugin(
 			conf:                      config,
 		},
 		metrics:   PromMetrics{},      //nolint:exhaustruct // set by makePrometheusRegistry
-		vmStore:   IndexedVMStore{},   //nolint:exhaustruct // set below
 		nodeStore: IndexedNodeStore{}, //nolint:exhaustruct // set below
 	}
 
@@ -195,13 +189,11 @@ func makeAutoscaleEnforcerPlugin(
 		return nil, fmt.Errorf("Error starting VM Migration watcher: %w", err)
 	}
 
-	p.vmStore = watch.NewIndexedStore(vmStore, watch.NewNameIndex[vmapi.VirtualMachine]())
-
 	watchMetrics.MustRegister(promReg)
 
 	// ... but before handling the events, read the current cluster state:
 	logger.Info("Reading initial cluster state")
-	if err = p.readClusterState(ctx, logger); err != nil {
+	if err = p.readClusterState(ctx, logger, vmStore); err != nil {
 		return nil, fmt.Errorf("Error reading cluster state: %w", err)
 	}
 

pkg/plugin/state.go

@@ -1228,7 +1228,11 @@ func (e *AutoscaleEnforcer) startMigration(ctx context.Context, logger *zap.Logg
 //
 // This method expects that all pluginState fields except pluginState.conf are set to their zero
 // value, and will panic otherwise. Accordingly, this is only called during plugin initialization.
-func (p *AutoscaleEnforcer) readClusterState(ctx context.Context, logger *zap.Logger) error {
+func (p *AutoscaleEnforcer) readClusterState(
+	ctx context.Context,
+	logger *zap.Logger,
+	vmStore *watch.Store[vmapi.VirtualMachine],
+) error {
 	logger = logger.With(zap.String("action", "read cluster state"))
 
 	p.state.lock.Lock()
@@ -1260,7 +1264,7 @@ func (p *AutoscaleEnforcer) readClusterState(ctx context.Context, logger *zap.Lo
 	// has already been made.
 
 	logger.Info("Fetching VMs from existing store")
-	vms := p.vmStore.Items()
+	vms := vmStore.Items()
 
 	logger.Info("Listing Pods")
 	pods, err := p.handle.ClientSet().CoreV1().Pods(corev1.NamespaceAll).List(ctx, metav1.ListOptions{})