refactor: move DependencyReference to apis/meta

Signed-off-by: Iam-karan-suresh <karansuresh.info@gmail.com>

Author: Iam-Karan-Suresh

apis/meta/dependencies.go

@@ -16,9 +16,41 @@ limitations under the License.
 
 package meta
 
+import "strings"
+
 // ObjectWithDependencies describes a Kubernetes resource object with dependencies.
 // +k8s:deepcopy-gen=false
 type ObjectWithDependencies interface {
-	// GetDependsOn returns a NamespacedObjectReference list the object depends on.
-	GetDependsOn() []NamespacedObjectReference
+	// GetDependsOn returns a DependencyReference list the object depends on.
+	GetDependsOn() []DependencyReference
+}
+
+// MakeDependsOn parses a list of dependency strings into DependencyReference
+// objects. Each dependency string can be in one of the following formats:
+//   - "name" - a dependency in the same namespace with no CEL expression
+//   - "namespace/name" - a dependency in a specific namespace
+//   - "name@readyExpr" - a dependency with a CEL readiness expression
+//   - "namespace/name@readyExpr" - a dependency in a specific namespace with a CEL expression
+func MakeDependsOn(deps []string) []DependencyReference {
+	refs := make([]DependencyReference, 0, len(deps))
+	for _, dep := range deps {
+		ref := DependencyReference{}
+
+		// Split off the CEL ready expression if present.
+		if idx := strings.Index(dep, "@"); idx != -1 {
+			ref.ReadyExpr = dep[idx+1:]
+			dep = dep[:idx]
+		}
+
+		// Split the namespace/name.
+		if parts := strings.SplitN(dep, "/", 2); len(parts) == 2 {
+			ref.Namespace = parts[0]
+			ref.Name = parts[1]
+		} else {
+			ref.Name = dep
+		}
+
+		refs = append(refs, ref)
+	}
+	return refs
 }

apis/meta/reference_types.go

@@ -43,6 +43,36 @@ func (in NamespacedObjectReference) String() string {
 	return in.Name
 }
 
+// DependencyReference defines a dependency on another resource.
+// It extends NamespacedObjectReference with an optional CEL expression
+// for custom readiness checks.
+type DependencyReference struct {
+	// Name of the referent.
+	// +required
+	Name string `json:"name"`
+
+	// Namespace of the referent, defaults to the namespace of the resource
+	// object that contains the reference.
+	// +optional
+	Namespace string `json:"namespace,omitempty"`
+
+	// ReadyExpr is a CEL expression that can be used to assess the readiness
+	// of a dependency. When specified, the built-in readiness check
+	// is replaced by the logic defined in the CEL expression.
+	// To make the CEL expression additive to the built-in readiness check,
+	// the feature gate `AdditiveCELDependencyCheck` must be set to `true`.
+	// +optional
+	ReadyExpr string `json:"readyExpr,omitempty"`
+}
+
+// String implements the fmt.Stringer interface for DependencyReference.
+func (in DependencyReference) String() string {
+	if in.Namespace != "" {
+		return in.Namespace + "/" + in.Name
+	}
+	return in.Name
+}
+
 // NamespacedObjectKindReference contains enough information to locate the typed referenced Kubernetes resource object
 // in any namespace.
 type NamespacedObjectKindReference struct {

apis/meta/zz_generated.deepcopy.go

@@ -56,7 +56,11 @@ func Sort(objects []Dependent) ([]meta.NamespacedObjectReference, error) {
 			Namespace: obj.GetNamespace(),
 		}
 		vertices = append(vertices, u)
-		for _, v := range obj.GetDependsOn() {
+		for _, dep := range obj.GetDependsOn() {
+			v := meta.NamespacedObjectReference{
+				Name:      dep.Name,
+				Namespace: dep.Namespace,
+			}
 			if v.Namespace == "" {
 				v.Namespace = obj.GetNamespace()
 			}

runtime/dependency/sort.go

@@ -28,7 +28,7 @@ import (
 type object struct {
 	name      string
 	namespace string
-	dependsOn []meta.NamespacedObjectReference
+	dependsOn []meta.DependencyReference
 }
 
 func (in object) GetName() string {
@@ -39,7 +39,7 @@ func (in object) GetNamespace() string {
 	return in.namespace
 }
 
-func (in object) GetDependsOn() []meta.NamespacedObjectReference {
+func (in object) GetDependsOn() []meta.DependencyReference {
 	return in.dependsOn
 }
 
@@ -56,7 +56,7 @@ func TestSort(t *testing.T) {
 				&object{
 					name:      "frontend",
 					namespace: "default",
-					dependsOn: []meta.NamespacedObjectReference{
+					dependsOn: []meta.DependencyReference{
 						{Namespace: "linkerd", Name: "linkerd"},
 						{Namespace: "default", Name: "backend"},
 					},
@@ -68,7 +68,7 @@ func TestSort(t *testing.T) {
 				&object{
 					namespace: "default",
 					name:      "backend",
-					dependsOn: []meta.NamespacedObjectReference{
+					dependsOn: []meta.DependencyReference{
 						{Namespace: "linkerd", Name: "linkerd"},
 					},
 				},
@@ -85,21 +85,21 @@ func TestSort(t *testing.T) {
 				&object{
 					name:      "dependency",
 					namespace: "default",
-					dependsOn: []meta.NamespacedObjectReference{
+					dependsOn: []meta.DependencyReference{
 						{Namespace: "default", Name: "endless"},
 					},
 				},
 				&object{
 					name:      "endless",
 					namespace: "default",
-					dependsOn: []meta.NamespacedObjectReference{
+					dependsOn: []meta.DependencyReference{
 						{Namespace: "default", Name: "circular"},
 					},
 				},
 				&object{
 					name:      "circular",
 					namespace: "default",
-					dependsOn: []meta.NamespacedObjectReference{
+					dependsOn: []meta.DependencyReference{
 						{Namespace: "default", Name: "dependency"},
 					},
 				},
@@ -116,7 +116,7 @@ func TestSort(t *testing.T) {
 				&object{
 					name:      "frontend",
 					namespace: "application",
-					dependsOn: []meta.NamespacedObjectReference{
+					dependsOn: []meta.DependencyReference{
 						{Name: "backend"},
 					},
 				},
@@ -132,14 +132,14 @@ func TestSort(t *testing.T) {
 				&object{
 					name:      "backend",
 					namespace: "default",
-					dependsOn: []meta.NamespacedObjectReference{
+					dependsOn: []meta.DependencyReference{
 						{Namespace: "default", Name: "common"},
 					},
 				},
 				&object{
 					name:      "frontend",
 					namespace: "default",
-					dependsOn: []meta.NamespacedObjectReference{
+					dependsOn: []meta.DependencyReference{
 						{Namespace: "default", Name: "infra"},
 					},
 				},
@@ -161,7 +161,7 @@ func TestSort(t *testing.T) {
 				&object{
 					name:      "frontend",
 					namespace: "default",
-					dependsOn: []meta.NamespacedObjectReference{
+					dependsOn: []meta.DependencyReference{
 						{Namespace: "linkerd", Name: "linkerd"},
 						{Namespace: "default", Name: "backend"},
 					},