fix: ensure NillableDuration is round-trippable

pkg/apis/v1/duration.go

@@ -18,6 +18,8 @@ package v1
 
 import (
 	"encoding/json"
+	"fmt"
+	"slices"
 	"time"
 )
 
@@ -28,10 +30,15 @@ const Never = "Never"
 // that the duration is disabled and sets the inner duration as nil
 type NillableDuration struct {
 	*time.Duration
+
+	// Raw is used to ensure we remarshal the NillableDuration in the same format it was specified.
+	// This ensures tools like Flux and ArgoCD don't mistakenly detect drift due to our conversion webhooks.
+	Raw []byte
 }
 
 // UnmarshalJSON implements the json.Unmarshaller interface.
 func (d *NillableDuration) UnmarshalJSON(b []byte) error {
+	fmt.Printf("raw string (0): %s\n", string(b))
 	var str string
 	err := json.Unmarshal(b, &str)
 	if err != nil {
@@ -40,26 +47,34 @@ func (d *NillableDuration) UnmarshalJSON(b []byte) error {
 	if str == Never {
 		return nil
 	}
+	fmt.Printf("raw string (1): %s\n", str)
 	pd, err := time.ParseDuration(str)
 	if err != nil {
 		return err
 	}
+	d.Raw = slices.Clone(b)
 	d.Duration = &pd
 	return nil
 }
 
 // MarshalJSON implements the json.Marshaler interface.
 func (d NillableDuration) MarshalJSON() ([]byte, error) {
-	if d.Duration == nil {
-		return json.Marshal(Never)
+	if d.Raw != nil {
+		return d.Raw, nil
+	}
+	if d.Duration != nil {
+		return json.Marshal(d.Duration.String())
 	}
-	return json.Marshal(d.Duration.String())
+	return json.Marshal(Never)
 }
 
 // ToUnstructured implements the value.UnstructuredConverter interface.
 func (d NillableDuration) ToUnstructured() interface{} {
-	if d.Duration == nil {
-		return Never
+	if d.Raw != nil {
+		return d.Raw
+	}
+	if d.Duration != nil {
+		return d.Duration.String()
 	}
-	return d.Duration.String()
+	return Never
 }

pkg/apis/v1/nodepool_conversion.go

@@ -196,3 +196,13 @@ func (in *NodeClaimTemplate) convertFrom(ctx context.Context, v1beta1np *v1beta1
 
 	return "", nil
 }
+
+// func (in *NillableDuration) convertFrom(src *v1beta1.NillableDuration) {
+// 	in.Raw = slices.Clone(src.Raw)
+// 	in.Duration = lo.ToPtr(*src.Duration)
+// }
+//
+// func (in *NillableDuration) convertTo(dst *v1beta1.NillableDuration) {
+// 	dst.Raw = slices.Clone(in.Raw)
+// 	dst.Duration = lo.ToPtr(*in.Duration)
+// }

pkg/apis/v1/nodepool_conversion_test.go

@@ -18,6 +18,7 @@ package v1_test
 
 import (
 	"encoding/json"
+	"fmt"
 	"time"
 
 	"sigs.k8s.io/karpenter/pkg/test/v1alpha1"
@@ -269,6 +270,24 @@ var _ = Describe("Convert V1 to V1beta1 NodePool API", func() {
 			Expect(v1beta1nodepool.Status.Resources[resource]).To(Equal(v1nodepool.Status.Resources[resource]))
 		}
 	})
+	Context("Round Trip", func() {
+		DescribeTable(
+			"NillableDuration",
+			func(value string, field func() *NillableDuration) {
+				str := fmt.Sprintf("%q", value)
+				duration := NillableDuration{}
+				Expect(json.Unmarshal([]byte(str), &duration)).Should(Succeed())
+				*field() = duration
+				Expect(v1nodepool.ConvertTo(ctx, v1beta1nodepool)).To(Succeed())
+				Expect(v1nodepool.ConvertFrom(ctx, v1beta1nodepool)).To(Succeed())
+				result, err := json.Marshal(*field())
+				Expect(err).To(BeNil())
+				Expect(string(result)).To(Equal(str))
+			},
+			Entry("spec.template.spec.expireAfter", "720h", func() *NillableDuration { return &v1nodepool.Spec.Template.Spec.ExpireAfter }),
+			Entry("spec.disruption.consolidateAfter", "15m", func() *NillableDuration { return &v1nodepool.Spec.Disruption.ConsolidateAfter }),
+		)
+	})
 })
 
 var _ = Describe("Convert V1beta1 to V1 NodePool API", func() {
@@ -537,4 +556,27 @@ var _ = Describe("Convert V1beta1 to V1 NodePool API", func() {
 			Expect(v1beta1nodepool.Status.Resources[resource]).To(Equal(v1nodepool.Status.Resources[resource]))
 		}
 	})
+	Context("Round Trip", func() {
+		DescribeTable(
+			"NillableDuration",
+			func(value string, field func() *v1beta1.NillableDuration) {
+				str := fmt.Sprintf("%q", value)
+				duration := v1beta1.NillableDuration{}
+				Expect(json.Unmarshal([]byte(str), &duration)).Should(Succeed())
+				*field() = duration
+				Expect(v1nodepool.ConvertFrom(ctx, v1beta1nodepool)).To(Succeed())
+				Expect(v1nodepool.ConvertTo(ctx, v1beta1nodepool)).To(Succeed())
+				result, err := json.Marshal(*field())
+				Expect(err).To(BeNil())
+				Expect(string(result)).To(Equal(str))
+			},
+			Entry("spec.template.spec.expireAfter", "720h", func() *v1beta1.NillableDuration { return &v1beta1nodepool.Spec.Disruption.ExpireAfter }),
+			Entry("spec.disruption.consolidateAfter", "15m", func() *v1beta1.NillableDuration {
+				if v1beta1nodepool.Spec.Disruption.ConsolidateAfter == nil {
+					v1beta1nodepool.Spec.Disruption.ConsolidateAfter = &v1beta1.NillableDuration{}
+				}
+				return v1beta1nodepool.Spec.Disruption.ConsolidateAfter
+			}),
+		)
+	})
 })

pkg/apis/v1beta1/duration.go

@@ -18,6 +18,8 @@ package v1beta1
 
 import (
 	"encoding/json"
+	"fmt"
+	"slices"
 	"time"
 )
 
@@ -28,10 +30,15 @@ const Never = "Never"
 // that the duration is disabled and sets the inner duration as nil
 type NillableDuration struct {
 	*time.Duration
+
+	// Raw is used to ensure we remarshal the NillableDuration in the same format it was specified.
+	// This ensures tools like Flux and ArgoCD don't mistakenly detect drift due to our conversion webhooks.
+	Raw []byte
 }
 
 // UnmarshalJSON implements the json.Unmarshaller interface.
 func (d *NillableDuration) UnmarshalJSON(b []byte) error {
+	fmt.Printf("raw string (0): %s\n", string(b))
 	var str string
 	err := json.Unmarshal(b, &str)
 	if err != nil {
@@ -40,26 +47,34 @@ func (d *NillableDuration) UnmarshalJSON(b []byte) error {
 	if str == Never {
 		return nil
 	}
+	fmt.Printf("raw string (1): %s\n", str)
 	pd, err := time.ParseDuration(str)
 	if err != nil {
 		return err
 	}
+	d.Raw = slices.Clone(b)
 	d.Duration = &pd
 	return nil
 }
 
 // MarshalJSON implements the json.Marshaler interface.
 func (d NillableDuration) MarshalJSON() ([]byte, error) {
-	if d.Duration == nil {
-		return json.Marshal(Never)
+	if d.Raw != nil {
+		return d.Raw, nil
+	}
+	if d.Duration != nil {
+		return json.Marshal(d.Duration.String())
 	}
-	return json.Marshal(d.Duration.String())
+	return json.Marshal(Never)
 }
 
 // ToUnstructured implements the value.UnstructuredConverter interface.
 func (d NillableDuration) ToUnstructured() interface{} {
-	if d.Duration == nil {
-		return Never
+	if d.Raw != nil {
+		return d.Raw
+	}
+	if d.Duration != nil {
+		return d.Duration.String()
 	}
-	return d.Duration.String()
+	return Never
 }