feat: Support OpenShift-specific topologies

pkg/manifests/manifests.go

@@ -346,6 +346,9 @@ type Factory struct {
 type InfrastructureReader interface {
 	HighlyAvailableInfrastructure() bool
 	HostedControlPlane() bool
+	SingleNodeControlPlane() bool
+	TwoNodeControlPlane() bool
+	HighlyAvailableControlPlane() bool
 }
 
 // ProxyReader has methods to describe the proxy configuration.
@@ -2475,24 +2478,38 @@ func (f *Factory) ControlPlanePrometheusRule() (*monv1.PrometheusRule, error) {
 
 	r.Namespace = f.namespace
 
-	if f.infrastructure.HostedControlPlane() {
-		groups := []monv1.RuleGroup{}
-		for _, g := range r.Spec.Groups {
-			switch g.Name {
-			case "kubernetes-system-apiserver",
-				"kubernetes-system-controller-manager",
-				"kubernetes-system-scheduler":
-				// skip
-			default:
-				groups = append(groups, g)
-			}
-		}
-		r.Spec.Groups = groups
+	switch {
+	case f.infrastructure.HostedControlPlane():
+		r.Spec.Groups = filterRuleGroups(r, []string{
+			"kubernetes-system-apiserver",
+			"kubernetes-system-controller-manager",
+			"kubernetes-system-scheduler",
+		})
+	case !f.infrastructure.HighlyAvailableControlPlane():
+		r.Spec.Groups = filterRuleGroups(r, []string{
+			// This group supports the SNO cluster configuration currently, but not TNO ones (TNA and TNF). This is
+			// because upstream is only concerned with the broader HA and non-HA scenarios, and not any
+			// OpenShift-specific cluster configurations.
+			"kubernetes-resources",
+		})
 	}
 
 	return r, nil
 }
 
+func filterRuleGroups(rule *monv1.PrometheusRule, ignoreGroups []string) (groups []monv1.RuleGroup) {
+	for _, g := range rule.Spec.Groups {
+		if slices.ContainsFunc(ignoreGroups, func(ig string) bool {
+			return g.Name == ig
+		}) {
+			continue
+		}
+		groups = append(groups, g)
+	}
+
+	return
+}
+
 func (f *Factory) ControlPlaneKubeletServiceMonitors() ([]*monv1.ServiceMonitor, error) {
 	return serviceMonitors(f.config.CollectionProfilesFeatureGateEnabled, f.ControlPlaneKubeletServiceMonitor, f.ControlPlaneKubeletMinimalServiceMonitor)
 }

pkg/manifests/manifests_test.go

@@ -40,6 +40,12 @@ import (
 type fakeInfrastructureReader struct {
 	highlyAvailableInfrastructure bool
 	hostedControlPlane            bool
+	singleNodeControlPlane        bool
+	twoNodeControlPlane           bool
+}
+
+func (f *fakeInfrastructureReader) HighlyAvailableControlPlane() bool {
+	return !f.singleNodeControlPlane && !f.twoNodeControlPlane
 }
 
 func (f *fakeInfrastructureReader) HighlyAvailableInfrastructure() bool {
@@ -50,8 +56,21 @@ func (f *fakeInfrastructureReader) HostedControlPlane() bool {
 	return f.hostedControlPlane
 }
 
+func (f *fakeInfrastructureReader) TwoNodeControlPlane() bool {
+	return f.twoNodeControlPlane
+}
+
+func (f *fakeInfrastructureReader) SingleNodeControlPlane() bool {
+	return f.singleNodeControlPlane
+}
+
 func defaultInfrastructureReader() InfrastructureReader {
-	return &fakeInfrastructureReader{highlyAvailableInfrastructure: true, hostedControlPlane: false}
+	return &fakeInfrastructureReader{
+		highlyAvailableInfrastructure: true,
+		hostedControlPlane:            false,
+		singleNodeControlPlane:        false,
+		twoNodeControlPlane:           false,
+	}
 }
 
 type fakeProxyReader struct {

pkg/operator/operator.go

@@ -58,6 +58,8 @@ import (
 type InfrastructureConfig struct {
 	highlyAvailableInfrastructure bool
 	hostedControlPlane            bool
+	singleNodeControlPlane        bool
+	twoNodeControlPlane           bool
 }
 
 var (
@@ -96,20 +98,43 @@ func NewDefaultInfrastructureConfig() *InfrastructureConfig {
 	return &InfrastructureConfig{
 		highlyAvailableInfrastructure: true,
 		hostedControlPlane:            false,
+		singleNodeControlPlane:        false,
+		twoNodeControlPlane:           false,
 	}
 }
 
 // NewInfrastructureConfig returns a new InfrastructureConfig from the given config.openshift.io/Infrastructure resource.
 func NewInfrastructureConfig(i *configv1.Infrastructure) *InfrastructureConfig {
 	ic := NewDefaultInfrastructureConfig()
 
+	// Data plane topology modes
+	// SNO
 	if i.Status.InfrastructureTopology == configv1.SingleReplicaTopologyMode {
 		ic.highlyAvailableInfrastructure = false
 	}
+
+	// TNO includes DualReplica and TNF topology modes. The latter is not exposed in openshift/api/config/v1 yet.
+	// TNA has a third etcd node, and considered to be highly available.
+	if i.Status.InfrastructureTopology == configv1.DualReplicaTopologyMode {
+		ic.highlyAvailableInfrastructure = false
+	}
+
+	// Control plane topology modes
+	// SNO
+	if i.Status.ControlPlaneTopology == configv1.SingleReplicaTopologyMode {
+		ic.singleNodeControlPlane = true
+	}
+
+	// TNO includes DualReplica and TNF topology modes. The latter is not exposed in openshift/api/config/v1 yet.
+	// TNA has a third etcd node, and considered to be highly available.
+	if i.Status.ControlPlaneTopology == configv1.DualReplicaTopologyMode {
+		ic.twoNodeControlPlane = true
+	}
+
+	// External topology mode is used for hosted control planes.
 	if i.Status.ControlPlaneTopology == configv1.ExternalTopologyMode {
 		ic.hostedControlPlane = true
 	}
-
 	return ic
 }
 
@@ -123,6 +148,24 @@ func (ic *InfrastructureConfig) HostedControlPlane() bool {
 	return ic.hostedControlPlane
 }
 
+// TwoNodeControlPlane implements the InfrastructureReader interface.
+func (ic *InfrastructureConfig) TwoNodeControlPlane() bool {
+	return ic.twoNodeControlPlane
+}
+
+// SingleNodeControlPlane implements the InfrastructureReader interface.
+func (ic *InfrastructureConfig) SingleNodeControlPlane() bool {
+	return ic.singleNodeControlPlane
+}
+
+// HighlyAvailableControlPlane implements the InfrastructureReader interface.
+func (ic *InfrastructureConfig) HighlyAvailableControlPlane() bool {
+	// Following the same pattern as we do for HighlyAvailableInfrastructure, i.e.,
+	// assuming topologies other than the currently known non-HA ones to be HA.
+	// Additionally, a cluster may have a non-HA control plane and an HA infrastructure, and vice versa.
+	return !ic.singleNodeControlPlane && !ic.twoNodeControlPlane
+}
+
 // ProxyConfig stores information about the proxy configuration.
 type ProxyConfig struct {
 	httpProxy  string