Return error on infra cluster and control plane discovery

If no control plane reference is set in the Cluster object the describe cluster
command will fail. We should validate the error in any case.

Signed-off-by: Tobias Giese <[email protected]>

Author: tobiasgiese

cmd/clusterctl/client/tree/discovery.go

@@ -19,6 +19,7 @@ package tree
 import (
 	"context"
 
+	"github.com/pkg/errors"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	unstructured "k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -83,9 +84,11 @@ func Discovery(ctx context.Context, c client.Client, namespace, name string, opt
 	tree := NewObjectTree(cluster, options.toObjectTreeOptions())
 
 	// Adds cluster infra
-	if clusterInfra, err := external.Get(ctx, c, cluster.Spec.InfrastructureRef, cluster.Namespace); err == nil {
-		tree.Add(cluster, clusterInfra, ObjectMetaName("ClusterInfrastructure"))
+	clusterInfra, err := external.Get(ctx, c, cluster.Spec.InfrastructureRef, cluster.Namespace)
+	if err != nil {
+		return nil, errors.Wrap(err, "get InfraCluster reference from Cluster")
 	}
+	tree.Add(cluster, clusterInfra, ObjectMetaName("ClusterInfrastructure"))
 
 	if options.ShowClusterResourceSets {
 		addClusterResourceSetsToObjectTree(ctx, c, cluster, tree)
@@ -119,9 +122,11 @@ func Discovery(ctx context.Context, c client.Client, namespace, name string, opt
 	}
 
 	controlPlaneMachines := selectControlPlaneMachines(machinesList)
-	for i := range controlPlaneMachines {
-		cp := controlPlaneMachines[i]
-		addMachineFunc(controlPlane, cp)
+	if controlPlane != nil {
+		for i := range controlPlaneMachines {
+			cp := controlPlaneMachines[i]
+			addMachineFunc(controlPlane, cp)
+		}
 	}
 
 	machinePoolList, err := getMachinePoolsInCluster(ctx, c, cluster.Namespace, cluster.Name)