[local] Hook in template only nodeinfos provider

Hooking it in the less intrusive way we could.
We'll work with upstream for a proper "nodeinfos processor" entrypoint
(and revisit this, depending on the outcome).

cluster-autoscaler/core/static_autoscaler.go

@@ -47,6 +47,9 @@ import (
 	klog "k8s.io/klog/v2"
 )
 
+// GetNodeInfosForGroups is a non intrusive entrypoint for nodeinfos provider override
+var GetNodeInfosForGroups = core_utils.GetNodeInfosForGroups
+
 const (
 	// How old the oldest unschedulable pod should be before starting scale up.
 	unschedulablePodTimeBuffer = 2 * time.Second
@@ -280,7 +283,7 @@ func (a *StaticAutoscaler) RunOnce(currentTime time.Time) errors.AutoscalerError
 		return typedErr.AddPrefix("Initialize ClusterSnapshot")
 	}
 
-	nodeInfosForGroups, autoscalerError := core_utils.GetNodeInfosForGroups(
+	nodeInfosForGroups, autoscalerError := GetNodeInfosForGroups(
 		readyNodes, a.nodeInfoCache, autoscalingContext.CloudProvider, autoscalingContext.ListerRegistry, daemonsets, autoscalingContext.PredicateChecker, a.ignoredTaints)
 	if autoscalerError != nil {
 		klog.Errorf("Failed to get node infos for groups: %v", autoscalerError)

cluster-autoscaler/main.go

@@ -31,6 +31,7 @@ import (
 
 	"github.com/spf13/pflag"
 
+	"k8s.io/autoscaler/cluster-autoscaler/processors/datadog/nodeinfosprovider"
 	"k8s.io/autoscaler/cluster-autoscaler/processors/datadog/pods"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -341,6 +342,10 @@ func buildAutoscaler() (core.Autoscaler, error) {
 	metrics.UpdateCPULimitsCores(autoscalingOptions.MinCoresTotal, autoscalingOptions.MaxCoresTotal)
 	metrics.UpdateMemoryLimitsBytes(autoscalingOptions.MinMemoryTotal, autoscalingOptions.MaxMemoryTotal)
 
+	// Datadog only: hook our "ASG template only" nodeInfos provider; not in the cleanest, but in the less
+	// intrusive and most rebase friendly way we can; until a "nodeInfos provider processor" makes it upstream.
+	core.GetNodeInfosForGroups = nodeinfosprovider.NewTemplateOnlyNodeInfoProvider().GetNodeInfosForGroups
+
 	// Create autoscaler.
 	return core.NewAutoscaler(opts)
 }