Emptiness reconcile now properly backs off

pkg/controllers/node/controller.go

@@ -20,7 +20,6 @@ import (
 	"time"
 
 	"github.com/awslabs/karpenter/pkg/apis/provisioning/v1alpha3"
-	"github.com/awslabs/karpenter/pkg/utils/functional"
 	"github.com/awslabs/karpenter/pkg/utils/result"
 
 	"go.uber.org/multierr"
@@ -88,7 +87,7 @@ func (c *Controller) Reconcile(ctx context.Context, req reconcile.Request) (reco
 
 	// 3. Execute reconcilers
 	node := stored.DeepCopy()
-	var backoffs []time.Duration
+	var results []reconcile.Result
 	var errs error
 	for _, reconciler := range []interface {
 		Reconcile(context.Context, *v1alpha3.Provisioner, *v1.Node) (reconcile.Result, error)
@@ -101,7 +100,7 @@ func (c *Controller) Reconcile(ctx context.Context, req reconcile.Request) (reco
 	} {
 		res, err := reconciler.Reconcile(ctx, provisioner, node)
 		errs = multierr.Append(errs, err)
-		backoffs = append(backoffs, res.RequeueAfter)
+		results = append(results, res)
 	}
 
 	// 4. Patch any changes, regardless of errors
@@ -114,7 +113,7 @@ func (c *Controller) Reconcile(ctx context.Context, req reconcile.Request) (reco
 	if errs != nil {
 		return result.RetryIfError(ctx, errs)
 	}
-	return reconcile.Result{RequeueAfter: functional.MaxDuration(backoffs...)}, nil
+	return result.MinResult(results...), nil
 }
 
 func (c *Controller) Register(ctx context.Context, m manager.Manager) error {

pkg/utils/functional/functional.go

@@ -16,7 +16,6 @@ package functional
 
 import (
 	"strings"
-	"time"
 
 	"go.uber.org/multierr"
 )
@@ -110,14 +109,3 @@ func InvertStringMap(stringMap map[string]string) map[string]string {
 	}
 	return inverted
 }
-
-// MaxDuration returns the largest duration
-func MaxDuration(durations ...time.Duration) time.Duration {
-	var max time.Duration
-	for _, duration := range durations {
-		if duration > max {
-			max = duration
-		}
-	}
-	return max
-}

pkg/utils/result/result.go

@@ -16,6 +16,8 @@ package result
 
 import (
 	"context"
+	"math"
+	"time"
 
 	"go.uber.org/multierr"
 	"knative.dev/pkg/logging"
@@ -29,3 +31,19 @@ func RetryIfError(ctx context.Context, err error) (reconcile.Result, error) {
 	}
 	return reconcile.Result{Requeue: err != nil}, nil
 }
+
+// MinResult returns the result that wants to requeue the soonest
+func MinResult(results ...reconcile.Result) (result reconcile.Result) {
+	min := time.Duration(math.MaxInt64)
+	for _, r := range results {
+		if r.IsZero() {
+			continue
+		}
+		if r.RequeueAfter < min {
+			min = r.RequeueAfter
+			result.RequeueAfter = min
+			result.Requeue = true
+		}
+	}
+	return
+}