Prevent patching the HybridOverlayConfig

Since adding a hybrid network after install time is not a supported
operation throw an error when processesing the config.

pkg/network/ovn_kubernetes.go

@@ -141,9 +141,12 @@ func isOVNKubernetesChangeSafe(prev, next *operv1.NetworkSpec) []error {
 	if !reflect.DeepEqual(pn.GenevePort, nn.GenevePort) {
 		errs = append(errs, errors.Errorf("cannot change ovn-kubernetes genevePort"))
 	}
+	if pn.HybridOverlayConfig == nil && nn.HybridOverlayConfig != nil {
+		errs = append(errs, errors.Errorf("cannot start a hybrid overlay network after install time"))
+	}
 	if pn.HybridOverlayConfig != nil {
 		if !reflect.DeepEqual(pn.HybridOverlayConfig, nn.HybridOverlayConfig) {
-			errs = append(errs, errors.Errorf("once set cannot change ovn-kubernetes Hybrid Overlay Config"))
+			errs = append(errs, errors.Errorf("cannot edit a running hybrid overlay network"))
 		}
 	}
 

pkg/network/ovn_kubernetes_test.go

@@ -262,6 +262,34 @@ func TestOVNKubernetesIsSafe(t *testing.T) {
 	errs := isOVNKubernetesChangeSafe(prev, next)
 	g.Expect(errs).To(BeEmpty())
 
+	// try to add a new hybrid overlay config
+	hybridOverlayConfigNext :=
+		operv1.HybridOverlayConfig{
+			HybridClusterNetwork: []operv1.ClusterNetworkEntry{
+				{CIDR: "10.132.0.0/14", HostPrefix: 23},
+			},
+		}
+	next.DefaultNetwork.OVNKubernetesConfig.HybridOverlayConfig = &hybridOverlayConfigNext
+
+	errs = isOVNKubernetesChangeSafe(prev, next)
+	g.Expect(errs).To(HaveLen(1))
+	g.Expect(errs[0]).To(MatchError("cannot start a hybrid overlay network after install time"))
+
+	//try to change a previous hybrid overlay
+	hybridOverlayConfigPrev :=
+		operv1.HybridOverlayConfig{
+			HybridClusterNetwork: []operv1.ClusterNetworkEntry{
+				{CIDR: "10.135.0.0/14", HostPrefix: 23},
+			},
+		}
+	prev.DefaultNetwork.OVNKubernetesConfig.HybridOverlayConfig = &hybridOverlayConfigPrev
+	errs = isOVNKubernetesChangeSafe(prev, next)
+	g.Expect(errs).To(HaveLen(1))
+	g.Expect(errs[0]).To(MatchError("cannot edit a running hybrid overlay network"))
+
+	prev.DefaultNetwork.OVNKubernetesConfig.HybridOverlayConfig = nil
+	next.DefaultNetwork.OVNKubernetesConfig.HybridOverlayConfig = nil
+
 	// change the mtu
 	mtu := uint32(70000)
 	next.DefaultNetwork.OVNKubernetesConfig.MTU = &mtu
@@ -273,4 +301,5 @@ func TestOVNKubernetesIsSafe(t *testing.T) {
 	g.Expect(errs).To(HaveLen(2))
 	g.Expect(errs[0]).To(MatchError("cannot change ovn-kubernetes MTU"))
 	g.Expect(errs[1]).To(MatchError("cannot change ovn-kubernetes genevePort"))
+
 }