fix: no nodeRefs when empty providerIDList is ok

This fixes MachinePool reconciliation when an empty providerIDList is
given. Previously it would always return an error in this case,
preventing the MachinePool readyReplicas etc. to go to 0.

Author: mweibel

exp/internal/controllers/machinepool_controller_noderef.go

@@ -221,7 +221,7 @@ func (r *MachinePoolReconciler) getNodeReferences(ctx context.Context, c client.
 		}
 	}
 
-	if len(nodeRefs) == 0 {
+	if len(nodeRefs) == 0 && len(providerIDList) != 0 {
 		return getNodeReferencesResult{}, errNoAvailableNodes
 	}
 	return getNodeReferencesResult{nodeRefs, available, ready}, nil

exp/internal/controllers/machinepool_controller_noderef_test.go

@@ -128,6 +128,15 @@ func TestMachinePoolGetNodeReference(t *testing.T) {
 			expected:       nil,
 			err:            errNoAvailableNodes,
 		},
+		{
+			name:           "no provider id, no node found",
+			providerIDList: []string{},
+			expected: &getNodeReferencesResult{
+				references: []corev1.ObjectReference{},
+				available:  0,
+				ready:      0,
+			},
+		},
 	}
 
 	for _, test := range testCases {