fix: Do not create PodDisruptionBudget in single replica topology mode

The PodDisruptionBudget does not make sense in single replica topology
mode. It would have "spec.minAvailable" set to 1, but there would always
be one pod. It would cause a warning to be always present:

"The pod disruption budget is at the minimum disruptions allowed level.
The number of current healthy pods is equal to the desired healthy
pods."

Assisted-by: Claude <noreply@anthropic.com>
Signed-off-by: Andrej Krejcir <akrejcir@redhat.com>

Author: akrejcir

internal/operands/template-validator/reconcile.go

@@ -72,7 +72,9 @@ func (t *templateValidator) Reconcile(request *common.Request) ([]common.Reconci
 		reconcileConfigMap,
 		reconcileDeployment,
 		reconcileValidatingWebhook,
-		reconcilePodDisruptionBudget,
+	}
+	if !request.IsSingleReplicaTopologyMode() {
+		funcs = append(funcs, reconcilePodDisruptionBudget)
 	}
 	funcs = append(funcs, reconcileNetworkPolicies(request)...)
 	return common.CollectResourceStatus(request, funcs...)

internal/operands/template-validator/reconcile_test.go

@@ -6,8 +6,9 @@ import (
 
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
-	securityv1 "github.com/openshift/api/security/v1"
 
+	osconfv1 "github.com/openshift/api/config/v1"
+	securityv1 "github.com/openshift/api/security/v1"
 	admission "k8s.io/api/admissionregistration/v1"
 	apps "k8s.io/api/apps/v1"
 	core "k8s.io/api/core/v1"
@@ -95,6 +96,15 @@ var _ = Describe("Template validator operand", func() {
 		}
 	})
 
+	It("should not create PodDisruptionBudget when SingleReplicaTopologyMode is used", func() {
+		request.TopologyMode = osconfv1.SingleReplicaTopologyMode
+
+		_, err := operand.Reconcile(&request)
+		Expect(err).ToNot(HaveOccurred())
+
+		ExpectResourceNotExists(newPodDisruptionBudget(namespace), request)
+	})
+
 	It("should not update webhook CA bundle", func() {
 		_, err := operand.Reconcile(&request)
 		Expect(err).ToNot(HaveOccurred())

tests/single_node_test.go

@@ -4,9 +4,13 @@ import (
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 
+	policy "k8s.io/api/policy/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
 	"kubevirt.io/controller-lifecycle-operator-sdk/api"
+	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	ssp "kubevirt.io/ssp-operator/api/v1beta3"
+	validator "kubevirt.io/ssp-operator/internal/operands/template-validator"
 	"kubevirt.io/ssp-operator/tests/env"
 )
 
@@ -81,4 +85,10 @@ var _ = Describe("Single Node Topology", func() {
 		deployment := getTemplateValidatorDeployment()
 		Expect(int(deployment.Status.Replicas)).Should(Equal(0), "In Single Mode Topology the number of replicas is at most 1")
 	})
+
+	It("[test_id:TODO] PodDisruptionBudget should not be created", func() {
+		key := client.ObjectKey{Name: validator.DeploymentName, Namespace: strategy.GetNamespace()}
+		pdb := &policy.PodDisruptionBudget{}
+		Expect(apiClient.Get(ctx, key, pdb)).To(MatchError(errors.IsNotFound, "errors.IsNotFound"))
+	})
 })

tests/validator_test.go

@@ -214,9 +214,14 @@ var _ = Describe("Template validator operand", func() {
 			Entry("[test_id:4912] deployment", &deploymentRes),
 			Entry("[test_id:TODO] network policy kube api and dns", &networkPolicyKubeAPIAndDNSRes),
 			Entry("[test_id:TODO] network policy webhook and metrics", &networkPolicyWebhookAndMetricsRes),
-			Entry("[test_id:TODO] PodDisruptionBudget", &podDisruptionBudgetRes),
 		)
 
+		It("[test_id:TODO] PodDisruptionBudget", decorators.Conformance, func() {
+			strategy.SkipUnlessHighlyAvailableTopologyMode()
+			err := apiClient.Get(ctx, podDisruptionBudgetRes.GetKey(), podDisruptionBudgetRes.NewResource())
+			Expect(err).ToNot(HaveOccurred())
+		})
+
 		DescribeTable("should set app labels", expectAppLabels,
 			Entry("[test_id:5824]cluster role", &clusterRoleRes),
 			Entry("[test_id:5825]cluster role binding", &clusterRoleBindingRes),
@@ -228,8 +233,12 @@ var _ = Describe("Template validator operand", func() {
 			Entry("[test_id:5828]deployment", &deploymentRes),
 			Entry("[test_id:TODO]network policy kube api and dns", &networkPolicyKubeAPIAndDNSRes),
 			Entry("[test_id:TODO]network policy webhook and metrics", &networkPolicyWebhookAndMetricsRes),
-			Entry("[test_id:TODO] PodDisruptionBudget", &podDisruptionBudgetRes),
 		)
+
+		It("[test_id:TODO] should set app labels on PodDisruptionBudget", func() {
+			strategy.SkipUnlessHighlyAvailableTopologyMode()
+			expectAppLabels(&podDisruptionBudgetRes)
+		})
 	})
 
 	Context("resource deletion", func() {
@@ -244,8 +253,12 @@ var _ = Describe("Template validator operand", func() {
 			Entry("[test_id:4924] deployment", &deploymentRes),
 			Entry("[test_id:TODO] network policy kube api and dns", &networkPolicyKubeAPIAndDNSRes),
 			Entry("[test_id:TODO] network policy webhook and metrics", &networkPolicyWebhookAndMetricsRes),
-			Entry("[test_id:TODO] PodDisruptionBudget", &podDisruptionBudgetRes),
 		)
+
+		It("[test_id:TODO] PodDisruptionBudget recreate after delete", decorators.Conformance, func() {
+			strategy.SkipUnlessHighlyAvailableTopologyMode()
+			expectRecreateAfterDelete(&podDisruptionBudgetRes)
+		})
 	})
 
 	Context("resource change", func() {
@@ -259,9 +272,13 @@ var _ = Describe("Template validator operand", func() {
 			Entry("[test_id:4925] deployment", &deploymentRes),
 			Entry("[test_id:TODO] network policy kube api and dns", &networkPolicyKubeAPIAndDNSRes),
 			Entry("[test_id:TODO] network policy webhook and metrics", &networkPolicyWebhookAndMetricsRes),
-			Entry("[test_id:TODO] PodDisruptionBudget", &podDisruptionBudgetRes),
 		)
 
+		It("[test_id:TODO] should restore modified PodDisruptionBudget", decorators.Conformance, func() {
+			strategy.SkipUnlessHighlyAvailableTopologyMode()
+			expectRestoreAfterUpdate(&podDisruptionBudgetRes)
+		})
+
 		Context("with pause", func() {
 			BeforeEach(func() {
 				strategy.SkipSspUpdateTestsIfNeeded()
@@ -281,8 +298,12 @@ var _ = Describe("Template validator operand", func() {
 				Entry("[test_id:5539] deployment", &deploymentRes),
 				Entry("[test_id:TODO] network policy kube api and dns", &networkPolicyKubeAPIAndDNSRes),
 				Entry("[test_id:TODO] network policy webhook and metrics", &networkPolicyWebhookAndMetricsRes),
-				Entry("[test_id:TODO] PodDisruptionBudget", &podDisruptionBudgetRes),
 			)
+
+			It("[test_id:TODO] should restore modified PodDisruptionBudget with pause", decorators.Conformance, func() {
+				strategy.SkipUnlessHighlyAvailableTopologyMode()
+				expectRestoreAfterUpdateWithPause(&podDisruptionBudgetRes)
+			})
 		})
 
 		DescribeTable("should restore modified app labels", expectAppLabelsRestoreAfterUpdate,
@@ -295,8 +316,12 @@ var _ = Describe("Template validator operand", func() {
 			Entry("[test_id:6209] deployment", &deploymentRes),
 			Entry("[test_id:TODO] network policy kube api and dns", &networkPolicyKubeAPIAndDNSRes),
 			Entry("[test_id:TODO] network policy webhook and metrics", &networkPolicyWebhookAndMetricsRes),
-			Entry("[test_id:TODO] PodDisruptionBudget", &podDisruptionBudgetRes),
 		)
+
+		It("[test_id:TODO] should restore modified app labels on PodDisruptionBudget", func() {
+			strategy.SkipUnlessHighlyAvailableTopologyMode()
+			expectAppLabelsRestoreAfterUpdate(&podDisruptionBudgetRes)
+		})
 	})
 
 	It("[test_id:4913] should successfully start template-validator pod", decorators.Conformance, func() {