Fix nodePlugin affinity not propagating from OperatorConfig to DaemonSet

Rook creates Driver CRs with a non-nil but empty Affinity struct.
The merge logic only checked if Affinity == nil, so the affinity
from OperatorConfig.driverSpecDefaults was never applied.

Add isAffinityEmpty() helper to check for nil or effectively empty
affinity structs, allowing the merge to properly fill in defaults.

Signed-off-by: ksc98 <kylechang96@gmail.com>

Author: ksc98

internal/controller/driver_controller.go

@@ -1731,7 +1731,7 @@ func mergeDriverSpecs(dest, src *csiv1.DriverSpec) {
 			if dest.Annotations == nil {
 				dest.Annotations = src.Annotations
 			}
-			if dest.Affinity == nil {
+			if isAffinityEmpty(dest.Affinity) {
 				dest.Affinity = src.Affinity
 			}
 			if dest.Tolerations == nil {
@@ -1786,7 +1786,7 @@ func mergeDriverSpecs(dest, src *csiv1.DriverSpec) {
 			if dest.Annotations == nil {
 				dest.Annotations = src.Annotations
 			}
-			if dest.Affinity == nil {
+			if isAffinityEmpty(dest.Affinity) {
 				dest.Affinity = src.Affinity
 			}
 			if dest.Tolerations == nil {
@@ -1855,3 +1855,14 @@ func mergeDriverSpecs(dest, src *csiv1.DriverSpec) {
 		dest.CephFsClientType = src.CephFsClientType
 	}
 }
+
+// isAffinityEmpty checks if an Affinity is nil or has no meaningful content.
+// This handles the case where an Affinity struct is non-nil but contains only
+// empty nested structs (e.g., &Affinity{NodeAffinity: &NodeAffinity{}}).
+func isAffinityEmpty(affinity *corev1.Affinity) bool {
+	if affinity == nil {
+		return true
+	}
+	return reflect.DeepEqual(affinity, &corev1.Affinity{}) ||
+		reflect.DeepEqual(affinity, &corev1.Affinity{NodeAffinity: &corev1.NodeAffinity{}})
+}

internal/controller/driver_controller_test.go

@@ -21,12 +21,12 @@ import (
 
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
+	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-
 	csiv1 "github.com/ceph/ceph-csi-operator/api/v1"
 )
 
@@ -82,3 +82,41 @@ var _ = Describe("Driver Controller", func() {
 		})
 	})
 })
+
+var _ = Describe("isAffinityEmpty", func() {
+	It("should return true for nil affinity", func() {
+		Expect(isAffinityEmpty(nil)).To(BeTrue())
+	})
+
+	It("should return true for empty affinity struct", func() {
+		Expect(isAffinityEmpty(&corev1.Affinity{})).To(BeTrue())
+	})
+
+	It("should return true for affinity with empty NodeAffinity", func() {
+		affinity := &corev1.Affinity{
+			NodeAffinity: &corev1.NodeAffinity{},
+		}
+		Expect(isAffinityEmpty(affinity)).To(BeTrue())
+	})
+
+	It("should return false for affinity with NodeAffinity content", func() {
+		affinity := &corev1.Affinity{
+			NodeAffinity: &corev1.NodeAffinity{
+				RequiredDuringSchedulingIgnoredDuringExecution: &corev1.NodeSelector{
+					NodeSelectorTerms: []corev1.NodeSelectorTerm{
+						{
+							MatchExpressions: []corev1.NodeSelectorRequirement{
+								{
+									Key:      "kubernetes.io/hostname",
+									Operator: corev1.NodeSelectorOpNotIn,
+									Values:   []string{"node1"},
+								},
+							},
+						},
+					},
+				},
+			},
+		}
+		Expect(isAffinityEmpty(affinity)).To(BeFalse())
+	})
+})