fix: autoscaling annotation format and empty image guard

pkg/functions/function.go

@@ -862,6 +862,9 @@ func (f Function) ImageNameWithDigest(newDigest string) string {
 		return f.Build.Image
 	}
 	image := f.Build.Image
+	if image == "" {
+		return ""
+	}
 
 	// overwrite current digest
 	shaIndex := strings.Index(image, "@sha256:")

pkg/knative/deployer.go

@@ -589,13 +589,13 @@ func setServiceOptions(template *servingv1.RevisionTemplateSpec, options fn.Opti
 		}
 
 		if options.Scale.Target != nil {
-			toUpdate[autoscaling.TargetAnnotationKey] = fmt.Sprintf("%f", *options.Scale.Target)
+			toUpdate[autoscaling.TargetAnnotationKey] = fmt.Sprintf("%g", *options.Scale.Target)
 		} else {
 			toRemove = append(toRemove, autoscaling.TargetAnnotationKey)
 		}
 
 		if options.Scale.Utilization != nil {
-			toUpdate[autoscaling.TargetUtilizationPercentageKey] = fmt.Sprintf("%f", *options.Scale.Utilization)
+			toUpdate[autoscaling.TargetUtilizationPercentageKey] = fmt.Sprintf("%g", *options.Scale.Utilization)
 		} else {
 			toRemove = append(toRemove, autoscaling.TargetUtilizationPercentageKey)
 		}

pkg/knative/deployer_test.go

@@ -29,6 +29,7 @@ import (
 	v1 "k8s.io/client-go/kubernetes/typed/core/v1"
 	fn "knative.dev/func/pkg/functions"
 	"knative.dev/pkg/ptr"
+	"knative.dev/serving/pkg/apis/autoscaling"
 	servingv1 "knative.dev/serving/pkg/apis/serving/v1"
 )
 
@@ -451,6 +452,35 @@ func TestGenerateNewService_ResourceSetsPopulated(t *testing.T) {
 	}
 }
 
+func TestSetServiceOptions_ScaleAnnotationFormat(t *testing.T) {
+	target := 100.0
+	utilization := 70.0
+	template := &servingv1.RevisionTemplateSpec{
+		Spec: servingv1.RevisionSpec{
+			PodSpec: corev1.PodSpec{
+				Containers: []corev1.Container{{}},
+			},
+		},
+	}
+	options := fn.Options{
+		Scale: &fn.ScaleOptions{
+			Target:      &target,
+			Utilization: &utilization,
+		},
+	}
+
+	if err := setServiceOptions(template, options); err != nil {
+		t.Fatalf("setServiceOptions returned unexpected error: %v", err)
+	}
+
+	if got := template.Annotations[autoscaling.TargetAnnotationKey]; got != "100" {
+		t.Errorf("expected target annotation to be %q, got %q", "100", got)
+	}
+	if got := template.Annotations[autoscaling.TargetUtilizationPercentageKey]; got != "70" {
+		t.Errorf("expected utilization annotation to be %q, got %q", "70", got)
+	}
+}
+
 func assertAuth(uname, pwd string, w http.ResponseWriter, r *http.Request) bool {
 	user, pass, ok := r.BasicAuth()
 	if ok && user == uname && pass == pwd {