Merge pull request #11197 from chrischdi/pr-fix-cc-nil-workers

🐛 clusterclass: fix nil pointer for empty workers in webhook

Author: k8s-ci-robot

internal/webhooks/cluster.go

@@ -772,17 +772,19 @@ func DefaultAndValidateVariables(ctx context.Context, cluster, oldCluster *clust
 			oldCPOverrides = oldCluster.Spec.Topology.ControlPlane.Variables.Overrides
 		}
 
-		oldMDVariables = make(map[string][]clusterv1.ClusterVariable, len(oldCluster.Spec.Topology.Workers.MachineDeployments))
-		for _, md := range oldCluster.Spec.Topology.Workers.MachineDeployments {
-			if md.Variables != nil {
-				oldMDVariables[md.Name] = md.Variables.Overrides
+		if oldCluster.Spec.Topology.Workers != nil {
+			oldMDVariables = make(map[string][]clusterv1.ClusterVariable, len(oldCluster.Spec.Topology.Workers.MachineDeployments))
+			for _, md := range oldCluster.Spec.Topology.Workers.MachineDeployments {
+				if md.Variables != nil {
+					oldMDVariables[md.Name] = md.Variables.Overrides
+				}
 			}
-		}
 
-		oldMPVariables = make(map[string][]clusterv1.ClusterVariable, len(oldCluster.Spec.Topology.Workers.MachinePools))
-		for _, mp := range oldCluster.Spec.Topology.Workers.MachinePools {
-			if mp.Variables != nil {
-				oldMPVariables[mp.Name] = mp.Variables.Overrides
+			oldMPVariables = make(map[string][]clusterv1.ClusterVariable, len(oldCluster.Spec.Topology.Workers.MachinePools))
+			for _, mp := range oldCluster.Spec.Topology.Workers.MachinePools {
+				if mp.Variables != nil {
+					oldMPVariables[mp.Name] = mp.Variables.Overrides
+				}
 			}
 		}
 	}

internal/webhooks/cluster_test.go

@@ -164,6 +164,18 @@ func TestClusterDefaultAndValidateVariables(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "should pass with empty oldTopology",
+			clusterClass: builder.ClusterClass(metav1.NamespaceDefault, "class1").
+				Build(),
+			topology:    &clusterv1.Topology{},
+			oldTopology: &clusterv1.Topology{},
+			expect: &clusterv1.Topology{
+				Class:     "class1",
+				Version:   "v1.22.2",
+				Variables: []clusterv1.ClusterVariable{},
+			},
+		},
 		{
 			name: "don't change a variable if it is already set",
 			clusterClass: builder.ClusterClass(metav1.NamespaceDefault, "class1").