[release-4.18] OCPBUGS-46411: skip generating certs when networkConfig.status.ServiceNetwork is nil

pkg/operator/certrotationcontroller/servicehostname.go

@@ -25,6 +25,12 @@ func (c *CertRotationController) syncServiceHostnames() error {
 	if err != nil {
 		return err
 	}
+
+	// skip when the status.serviceNetwork is nil
+	if len(networkConfig.Status.ServiceNetwork) == 0 {
+		return fmt.Errorf("empty networkConfig ServiceNetwork, can't generate cert")
+	}
+
 	for _, cidrString := range networkConfig.Status.ServiceNetwork {
 		_, serviceCIDR, err := net.ParseCIDR(cidrString)
 		if err != nil {

pkg/operator/certrotationcontroller/servicehostname_test.go

@@ -0,0 +1,66 @@
+package certrotationcontroller
+
+import (
+	"fmt"
+	"testing"
+
+	configv1 "github.com/openshift/api/config/v1"
+	configv1listers "github.com/openshift/client-go/config/listers/config/v1"
+	"github.com/stretchr/testify/require"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/tools/cache"
+)
+
+func TestServiceHostNameFunc(t *testing.T) {
+	scenarios := []struct {
+		name          string
+		objects       []runtime.Object
+		expectedError error
+	}{
+		{
+			"network config status not available",
+			[]runtime.Object{
+				fakeNetwork(false),
+			},
+			fmt.Errorf("empty networkConfig ServiceNetwork, can't generate cert"),
+		},
+		{
+			"happy with network status network ServiceNetwork",
+			[]runtime.Object{
+				fakeNetwork(true),
+			},
+			nil,
+		},
+	}
+
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			indexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
+			for _, obj := range scenario.objects {
+				if err := indexer.Add(obj); err != nil {
+					require.NoError(t, err)
+				}
+			}
+			controller := CertRotationController{
+				networkLister:  configv1listers.NewNetworkLister(indexer),
+				serviceNetwork: &DynamicServingRotation{hostnamesChanged: make(chan struct{}, 10)},
+			}
+			err := controller.syncServiceHostnames()
+			require.Equal(t, err, scenario.expectedError)
+		})
+	}
+}
+
+func fakeNetwork(hasServiceNetwork bool) *configv1.Network {
+	var serviceNetwork []string
+	if hasServiceNetwork {
+		serviceNetwork = []string{"10.0.1.0/24"}
+	} else {
+		serviceNetwork = []string{}
+	}
+	return &configv1.Network{
+		ObjectMeta: metav1.ObjectMeta{Name: "cluster"},
+		Status:     configv1.NetworkStatus{ServiceNetwork: serviceNetwork},
+	}
+}