TNF: add Two Node Fencing exception to allow less than two etcd endpoints

In a Two Node Fencing cluster (DualReplicaTopology) is it acceptable to
have less than two etcd endpoints.

Author: clobrano

pkg/monitortestlibrary/pathologicaleventlibrary/duplicated_event_patterns.go

@@ -499,6 +499,9 @@ func NewUniversalPathologicalEventMatchers(kubeConfig *rest.Config, finalInterva
 	newCrioReloadedTooOftenEventMatcher := newCrioReloadedTooOftenEventMatcher(finalIntervals)
 	registry.AddPathologicalEventMatcherOrDie(newCrioReloadedTooOftenEventMatcher)
 
+	twoNodeEtcdEndpointsMatcher := newTwoNodeEtcdEndpointsConfigMissingEventMatcher(finalIntervals)
+	registry.AddPathologicalEventMatcherOrDie(twoNodeEtcdEndpointsMatcher)
+
 	return registry
 }
 
@@ -715,6 +718,20 @@ var CertificateRotation = &SimplePathologicalEventMatcher{
 	messageReasonRegex: regexp.MustCompile(`^(CABundleUpdateRequired|SignerUpdateRequired|TargetUpdateRequired|CertificateUpdated|CertificateRemoved|CertificateUpdateFailed|CSRCreated|CSRApproved|CertificateRotationStarted|ClientCertificateCreated|NoValidCertificateFound)$`),
 }
 
+func newTwoNodeEtcdEndpointsConfigMissingEventMatcher(finalIntervals monitorapi.Intervals) EventMatcher {
+	// Use topology-based detection for DualReplica (two-node fencing) clusters
+	dualReplicaTopology := v1.DualReplicaTopologyMode
+	return &SimplePathologicalEventMatcher{
+		name: "EtcdEndpointsConfigMissingDuringTwoNodeTests",
+		locatorKeyRegexes: map[monitorapi.LocatorKey]*regexp.Regexp{
+			monitorapi.LocatorNamespaceKey: regexp.MustCompile(`^openshift-kube-apiserver-operator$`),
+		},
+		messageReasonRegex: regexp.MustCompile(`^ConfigMissing$`),
+		messageHumanRegex:  regexp.MustCompile(`apiServerArguments\.etcd-servers has less than two live etcd endpoints`),
+		topology:           &dualReplicaTopology,
+	}
+}
+
 // IsEventAfterInstallation returns true if the monitorEvent represents an event that happened after installation.
 func IsEventAfterInstallation(monitorEvent monitorapi.Interval, kubeClientConfig *rest.Config) (bool, error) {
 	if kubeClientConfig == nil {