ingress: handle ingress rule without HTTPIngressRule

Currently, defining an `Ingress` without an `HTTPIngressRule`
(e.g. only Host set) results in a panic in the Cilium Operator.

Therefore, this commit changes the ingress ingestion to process
the HTTP paths only if the HTTPIngressRule is set on the rule.

Signed-off-by: Marco Hofstetter <marco.hofstetter@isovalent.com>

operator/pkg/model/ingestion/ingress.go

@@ -90,6 +90,12 @@ func Ingress(ing slim_networkingv1.Ingress, defaultSecretNamespace, defaultSecre
 		}
 
 		l.Hostname = host
+		if rule.HTTP == nil {
+			log.WithField(logfields.Ingress, ing.Namespace+"/"+ing.Name).
+				Warn("Invalid Ingress rule without spec.rules.HTTP defined, skipping rule")
+			continue
+		}
+
 		for _, path := range rule.HTTP.Paths {
 
 			route := model.HTTPRoute{}

operator/pkg/model/ingestion/ingress_test.go

@@ -1270,14 +1270,28 @@ func useDefaultListenersTLSsecret(listeners []model.HTTPListener) []model.HTTPLi
 	return ret
 }
 
+func removeIngressHTTPRuleValues(ing slim_networkingv1.Ingress) slim_networkingv1.Ingress {
+	var rules []slim_networkingv1.IngressRule
+
+	for _, r := range ing.Spec.Rules {
+		r.HTTP = nil
+		rules = append(rules, r)
+	}
+
+	ret := slim_networkingv1.Ingress{}
+	ing.DeepCopyInto(&ret)
+	ret.Spec.Rules = rules
+
+	return ret
+}
+
 type testcase struct {
 	ingress       slim_networkingv1.Ingress
 	defaultSecret bool
 	want          []model.HTTPListener
 }
 
 func TestIngress(t *testing.T) {
-
 	tests := map[string]testcase{
 		"conformance default backend test": {
 			ingress: defaultBackend,
@@ -1291,6 +1305,10 @@ func TestIngress(t *testing.T) {
 			ingress: defaultBackendLegacyOverride,
 			want:    defaultBackendListeners,
 		},
+		"cilium test ingress without http rules": {
+			ingress: removeIngressHTTPRuleValues(hostRules),
+			want:    []model.HTTPListener{},
+		},
 		"conformance host rules test": {
 			ingress: hostRules,
 			want:    hostRulesListeners,