fix(controller): resolve GlobalTopoServer from templates correctly

Update `getGlobalTopoRef` to use the TemplateResolver, ensuring child resources receive the correct topology address when a `CoreTemplate` is used. Previously, this only supported inline specs.

Note: This commit includes updated test cases that cover both this fix and a separate name-length validation bug. The tests are expected to fail until the name-length validation logic is implemented in the next commit.

Author: fernando-villalba

pkg/cluster-handler/controller/multigrescluster/multigrescluster_controller.go

@@ -227,6 +227,12 @@ func (r *MultigresClusterReconciler) reconcileCells(ctx context.Context, cluster
 		return err
 	}
 
+	// Resolve Global Topo Reference ONCE for all cells
+	globalTopoRef, err := r.getGlobalTopoRef(ctx, cluster, resolver)
+	if err != nil {
+		return err
+	}
+
 	activeCellNames := make(map[string]bool)
 
 	allCellNames := []multigresv1alpha1.CellName{}
@@ -260,7 +266,7 @@ func (r *MultigresClusterReconciler) reconcileCells(ctx context.Context, cluster
 			cellCR.Spec.MultiGateway = gatewaySpec
 			cellCR.Spec.AllCells = allCellNames
 
-			cellCR.Spec.GlobalTopoServer = r.getGlobalTopoRef(cluster)
+			cellCR.Spec.GlobalTopoServer = globalTopoRef
 
 			if localTopoSpec != nil {
 				cellCR.Spec.TopoServer = *localTopoSpec
@@ -294,6 +300,12 @@ func (r *MultigresClusterReconciler) reconcileDatabases(ctx context.Context, clu
 		return err
 	}
 
+	// Resolve Global Topo Reference ONCE for all databases/shards
+	globalTopoRef, err := r.getGlobalTopoRef(ctx, cluster, resolver)
+	if err != nil {
+		return err
+	}
+
 	activeTGNames := make(map[string]bool)
 
 	for _, db := range cluster.Spec.Databases {
@@ -348,7 +360,7 @@ func (r *MultigresClusterReconciler) reconcileDatabases(ctx context.Context, clu
 					MultiPooler: cluster.Spec.Images.MultiPooler,
 					Postgres:    cluster.Spec.Images.Postgres,
 				}
-				tgCR.Spec.GlobalTopoServer = r.getGlobalTopoRef(cluster)
+				tgCR.Spec.GlobalTopoServer = globalTopoRef
 				tgCR.Spec.Shards = resolvedShards
 
 				return controllerutil.SetControllerReference(cluster, tgCR, r.Scheme)
@@ -370,19 +382,35 @@ func (r *MultigresClusterReconciler) reconcileDatabases(ctx context.Context, clu
 	return nil
 }
 
-func (r *MultigresClusterReconciler) getGlobalTopoRef(cluster *multigresv1alpha1.MultigresCluster) multigresv1alpha1.GlobalTopoServerRef {
+func (r *MultigresClusterReconciler) getGlobalTopoRef(ctx context.Context, cluster *multigresv1alpha1.MultigresCluster, resolver *TemplateResolver) (multigresv1alpha1.GlobalTopoServerRef, error) {
+	// 1. Determine Template Name
+	topoTplName := cluster.Spec.TemplateDefaults.CoreTemplate
+	if cluster.Spec.GlobalTopoServer.TemplateRef != "" {
+		topoTplName = cluster.Spec.GlobalTopoServer.TemplateRef
+	}
+
+	// 2. Resolve Template
+	topoTpl, err := resolver.ResolveCoreTemplate(ctx, topoTplName)
+	if err != nil {
+		return multigresv1alpha1.GlobalTopoServerRef{}, err
+	}
+
+	// 3. Resolve Final Spec (Inline vs Template)
+	topoSpec := ResolveGlobalTopo(&cluster.Spec.GlobalTopoServer, topoTpl)
+
+	// 4. Construct Reference based on resolved spec
 	address := ""
-	if cluster.Spec.GlobalTopoServer.Etcd != nil {
+	if topoSpec.Etcd != nil {
 		address = fmt.Sprintf("%s-global-topo-client.%s.svc:2379", cluster.Name, cluster.Namespace)
-	} else if cluster.Spec.GlobalTopoServer.External != nil && len(cluster.Spec.GlobalTopoServer.External.Endpoints) > 0 {
-		address = string(cluster.Spec.GlobalTopoServer.External.Endpoints[0])
+	} else if topoSpec.External != nil && len(topoSpec.External.Endpoints) > 0 {
+		address = string(topoSpec.External.Endpoints[0])
 	}
 
 	return multigresv1alpha1.GlobalTopoServerRef{
 		Address:        address,
 		RootPath:       "/multigres/global",
 		Implementation: "etcd2",
-	}
+	}, nil
 }
 
 func (r *MultigresClusterReconciler) updateStatus(ctx context.Context, cluster *multigresv1alpha1.MultigresCluster) error {

pkg/cluster-handler/controller/multigrescluster/multigrescluster_controller_test.go

@@ -3,6 +3,7 @@ package multigrescluster
 import (
 	"context"
 	"errors"
+	"fmt"
 	"strings"
 	"testing"
 
@@ -210,6 +211,17 @@ func TestMultigresClusterReconciler_Reconcile(t *testing.T) {
 				if *deploy.Spec.Replicas != 5 {
 					t.Errorf("MultiAdmin did not use admin-core template, got replicas: %d", *deploy.Spec.Replicas)
 				}
+
+				// VERIFY FIX: Check that Child Cell received the correct Global Topo Address from the template
+				// This confirms getGlobalTopoRef resolved the template correctly
+				cell := &multigresv1alpha1.Cell{}
+				if err := c.Get(ctx, types.NamespacedName{Name: clusterName + "-zone-a", Namespace: namespace}, cell); err != nil {
+					t.Fatal(err)
+				}
+				expectedAddr := fmt.Sprintf("%s-global-topo-client.%s.svc:2379", clusterName, namespace)
+				if cell.Spec.GlobalTopoServer.Address != expectedAddr {
+					t.Errorf("Cell GlobalTopo address mismatch. Got %s, Want %s", cell.Spec.GlobalTopoServer.Address, expectedAddr)
+				}
 			},
 		},
 		{
@@ -231,6 +243,14 @@ func TestMultigresClusterReconciler_Reconcile(t *testing.T) {
 				if err := c.Get(ctx, types.NamespacedName{Name: clusterName + "-multiadmin", Namespace: namespace}, deploy); err != nil {
 					t.Fatal("MultiAdmin not created")
 				}
+				// Verify External Topo Propagated
+				cell := &multigresv1alpha1.Cell{}
+				if err := c.Get(ctx, types.NamespacedName{Name: clusterName + "-zone-a", Namespace: namespace}, cell); err != nil {
+					t.Fatal(err)
+				}
+				if cell.Spec.GlobalTopoServer.Address != "http://ext:2379" {
+					t.Errorf("External address not propagated. Got %s", cell.Spec.GlobalTopoServer.Address)
+				}
 			},
 		},
 		{
@@ -331,6 +351,7 @@ func TestMultigresClusterReconciler_Reconcile(t *testing.T) {
 			name: "Create: External Topo with Empty Endpoints",
 			cluster: func() *multigresv1alpha1.MultigresCluster {
 				c := baseCluster.DeepCopy()
+				c.Spec.TemplateDefaults.CoreTemplate = ""
 				c.Spec.GlobalTopoServer = multigresv1alpha1.GlobalTopoServerSpec{
 					External: &multigresv1alpha1.ExternalTopoServerSpec{
 						Endpoints: []multigresv1alpha1.EndpointUrl{},
@@ -387,7 +408,7 @@ func TestMultigresClusterReconciler_Reconcile(t *testing.T) {
 				return c
 			}(),
 			existingObjects: []client.Object{coreTpl, cellTpl, shardTpl},
-			expectError:     false,
+			expectError:     true, // FIXED: Now expects error
 			validate:        func(t *testing.T, c client.Client) {},
 		},
 		{

pkg/cluster-handler/controller/multigrescluster/template_logic.go

@@ -21,7 +21,13 @@ type TemplateResolver struct {
 	Defaults multigresv1alpha1.TemplateDefaults
 }
 
-// ResolveCoreTemplate fetches and resolves a CoreTemplate by name, handling defaults.
+// ResolveCoreTemplate determines the target CoreTemplate name and fetches it.
+//
+// If templateName is empty, it uses the following precedence:
+// 1. The cluster-level default defined in TemplateDefaults.
+// 2. A CoreTemplate named "default" found in the same namespace where MultigresCluster is deployed.
+//
+// If the resolved template is not found, it returns an empty CoreTemplate object and nil error.
 func (r *TemplateResolver) ResolveCoreTemplate(ctx context.Context, templateName string) (*multigresv1alpha1.CoreTemplate, error) {
 	name := templateName
 	if name == "" {