add pdb configuration toggle

charts/postgres-operator/values.yaml

@@ -114,6 +114,7 @@ configKubernetesCRD:
   cluster_name_label: cluster-name
   enable_pod_antiaffinity: false
   pod_antiaffinity_topology_key: "kubernetes.io/hostname"
+  enable_pod_disruption_budget: true
   secret_name_template: "{username}.{cluster}.credentials.{tprkind}.{tprgroup}"
   # inherited_labels:
   # - application

manifests/postgresql-operator-default-configuration.yaml

@@ -40,6 +40,7 @@ configuration:
     pod_management_policy: "ordered_ready"
     enable_pod_antiaffinity: false
     pod_antiaffinity_topology_key: "kubernetes.io/hostname"
+    enable_pod_disruption_budget: true
   postgres_pod_resources:
     default_cpu_request: 100m
     default_memory_request: 100Mi

pkg/apis/acid.zalan.do/v1/operator_configuration_type.go

@@ -67,6 +67,7 @@ type KubernetesMetaConfiguration struct {
 	EnablePodAntiAffinity      bool          `json:"enable_pod_antiaffinity,omitempty"`
 	PodAntiAffinityTopologyKey string        `json:"pod_antiaffinity_topology_key,omitempty"`
 	PodManagementPolicy        string        `json:"pod_management_policy,omitempty"`
+	EnablePodDisruptionBudget  bool          `json:"enable_pod_disruption_budget,omitempty"`
 }
 
 // PostgresPodResourcesDefaults defines the spec of default resources

pkg/cluster/k8sres.go

@@ -1274,6 +1274,11 @@ func (c *Cluster) generateCloneEnvironment(description *acidv1.CloneDescription)
 func (c *Cluster) generatePodDisruptionBudget() *policybeta1.PodDisruptionBudget {
 	minAvailable := intstr.FromInt(1)
 
+	// Is PodDisruptionBudget is disabled or if there is no master, set the budget to 0.
+	if (c.OpConfig.EnablePodDisruptionBudget != nil && !*c.OpConfig.EnablePodDisruptionBudget) || c.Spec.NumberOfInstances <= 0 {
+		minAvailable = intstr.FromInt(0)
+	}
+
 	return &policybeta1.PodDisruptionBudget{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      c.podDisruptionBudgetName(),

pkg/cluster/k8sres_test.go

@@ -1,6 +1,8 @@
 package cluster
 
 import (
+	"reflect"
+
 	"k8s.io/api/core/v1"
 
 	"testing"
@@ -9,6 +11,10 @@ import (
 	"github.com/zalando/postgres-operator/pkg/util/config"
 	"github.com/zalando/postgres-operator/pkg/util/constants"
 	"github.com/zalando/postgres-operator/pkg/util/k8sutil"
+
+	policyv1beta1 "k8s.io/api/policy/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/intstr"
 )
 
 func True() *bool {
@@ -21,6 +27,11 @@ func False() *bool {
 	return &b
 }
 
+func toIntStr(val int) *intstr.IntOrString {
+	b := intstr.FromInt(val)
+	return &b
+}
+
 func TestGenerateSpiloJSONConfiguration(t *testing.T) {
 	var cluster = New(
 		Config{
@@ -143,6 +154,113 @@ func TestCreateLoadBalancerLogic(t *testing.T) {
 	}
 }
 
+func TestGeneratePodDisruptionBudget(t *testing.T) {
+	tests := []struct {
+		c   *Cluster
+		out policyv1beta1.PodDisruptionBudget
+	}{
+		// With multiple instances.
+		{
+			New(
+				Config{OpConfig: config.Config{Resources: config.Resources{ClusterNameLabel: "cluster-name", PodRoleLabel: "spilo-role"}, PDBNameFormat: "postgres-{cluster}-pdb"}},
+				k8sutil.KubernetesClient{},
+				acidv1.Postgresql{
+					ObjectMeta: metav1.ObjectMeta{Name: "myapp-database", Namespace: "myapp"},
+					Spec:       acidv1.PostgresSpec{TeamID: "myapp", NumberOfInstances: 3}},
+				logger),
+			policyv1beta1.PodDisruptionBudget{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "postgres-myapp-database-pdb",
+					Namespace: "myapp",
+					Labels:    map[string]string{"team": "myapp", "cluster-name": "myapp-database"},
+				},
+				Spec: policyv1beta1.PodDisruptionBudgetSpec{
+					MinAvailable: toIntStr(1),
+					Selector: &metav1.LabelSelector{
+						MatchLabels: map[string]string{"spilo-role": "master", "cluster-name": "myapp-database"},
+					},
+				},
+			},
+		},
+		// With zero instances.
+		{
+			New(
+				Config{OpConfig: config.Config{Resources: config.Resources{ClusterNameLabel: "cluster-name", PodRoleLabel: "spilo-role"}, PDBNameFormat: "postgres-{cluster}-pdb"}},
+				k8sutil.KubernetesClient{},
+				acidv1.Postgresql{
+					ObjectMeta: metav1.ObjectMeta{Name: "myapp-database", Namespace: "myapp"},
+					Spec:       acidv1.PostgresSpec{TeamID: "myapp", NumberOfInstances: 0}},
+				logger),
+			policyv1beta1.PodDisruptionBudget{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "postgres-myapp-database-pdb",
+					Namespace: "myapp",
+					Labels:    map[string]string{"team": "myapp", "cluster-name": "myapp-database"},
+				},
+				Spec: policyv1beta1.PodDisruptionBudgetSpec{
+					MinAvailable: toIntStr(0),
+					Selector: &metav1.LabelSelector{
+						MatchLabels: map[string]string{"spilo-role": "master", "cluster-name": "myapp-database"},
+					},
+				},
+			},
+		},
+		// With PodDisruptionBudget disabled.
+		{
+			New(
+				Config{OpConfig: config.Config{Resources: config.Resources{ClusterNameLabel: "cluster-name", PodRoleLabel: "spilo-role"}, PDBNameFormat: "postgres-{cluster}-pdb", EnablePodDisruptionBudget: False()}},
+				k8sutil.KubernetesClient{},
+				acidv1.Postgresql{
+					ObjectMeta: metav1.ObjectMeta{Name: "myapp-database", Namespace: "myapp"},
+					Spec:       acidv1.PostgresSpec{TeamID: "myapp", NumberOfInstances: 3}},
+				logger),
+			policyv1beta1.PodDisruptionBudget{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "postgres-myapp-database-pdb",
+					Namespace: "myapp",
+					Labels:    map[string]string{"team": "myapp", "cluster-name": "myapp-database"},
+				},
+				Spec: policyv1beta1.PodDisruptionBudgetSpec{
+					MinAvailable: toIntStr(0),
+					Selector: &metav1.LabelSelector{
+						MatchLabels: map[string]string{"spilo-role": "master", "cluster-name": "myapp-database"},
+					},
+				},
+			},
+		},
+		// With non-default PDBNameFormat and PodDisruptionBudget explicitly enabled.
+		{
+			New(
+				Config{OpConfig: config.Config{Resources: config.Resources{ClusterNameLabel: "cluster-name", PodRoleLabel: "spilo-role"}, PDBNameFormat: "postgres-{cluster}-databass-budget", EnablePodDisruptionBudget: True()}},
+				k8sutil.KubernetesClient{},
+				acidv1.Postgresql{
+					ObjectMeta: metav1.ObjectMeta{Name: "myapp-database", Namespace: "myapp"},
+					Spec:       acidv1.PostgresSpec{TeamID: "myapp", NumberOfInstances: 3}},
+				logger),
+			policyv1beta1.PodDisruptionBudget{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "postgres-myapp-database-databass-budget",
+					Namespace: "myapp",
+					Labels:    map[string]string{"team": "myapp", "cluster-name": "myapp-database"},
+				},
+				Spec: policyv1beta1.PodDisruptionBudgetSpec{
+					MinAvailable: toIntStr(1),
+					Selector: &metav1.LabelSelector{
+						MatchLabels: map[string]string{"spilo-role": "master", "cluster-name": "myapp-database"},
+					},
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		result := tt.c.generatePodDisruptionBudget()
+		if !reflect.DeepEqual(*result, tt.out) {
+			t.Errorf("Expected PodDisruptionBudget: %#v, got %#v", tt.out, *result)
+		}
+	}
+}
+
 func TestShmVolume(t *testing.T) {
 	testName := "TestShmVolume"
 	tests := []struct {
@@ -269,6 +387,5 @@ func TestCloneEnv(t *testing.T) {
 			t.Errorf("%s %s: Expected env value %s, have %s instead",
 				testName, tt.subTest, tt.env.Value, env.Value)
 		}
-
 	}
 }

pkg/controller/operator_config.go

@@ -41,6 +41,7 @@ func (c *Controller) importConfigurationFromCRD(fromCRD *acidv1.OperatorConfigur
 	result.PodServiceAccountRoleBindingDefinition = fromCRD.Kubernetes.PodServiceAccountRoleBindingDefinition
 	result.PodEnvironmentConfigMap = fromCRD.Kubernetes.PodEnvironmentConfigMap
 	result.PodTerminateGracePeriod = time.Duration(fromCRD.Kubernetes.PodTerminateGracePeriod)
+	result.EnablePodDisruptionBudget = fromCRD.Kubernetes.EnablePodDisruptionBudget
 	result.SpiloPrivileged = fromCRD.Kubernetes.SpiloPrivileged
 	result.SpiloFSGroup = fromCRD.Kubernetes.SpiloFSGroup
 	result.ClusterDomain = fromCRD.Kubernetes.ClusterDomain

pkg/util/config/config.go

@@ -121,9 +121,10 @@ type Config struct {
 	TeamAPIRoleConfiguration  map[string]string `name:"team_api_role_configuration" default:"log_statement:all"`
 	PodTerminateGracePeriod   time.Duration     `name:"pod_terminate_grace_period" default:"5m"`
 	PodManagementPolicy       string            `name:"pod_management_policy" default:"ordered_ready"`
+	EnablePodDisruptionBudget *bool             `name:"enable_pod_disruption_budget" default:"true"`
 	ProtectedRoles            []string          `name:"protected_role_names" default:"admin"`
 	PostgresSuperuserTeams    []string          `name:"postgres_superuser_teams" default:""`
-	SetMemoryRequestToLimit  bool              `name:"set_memory_request_to_limit" defaults:"false"`
+	SetMemoryRequestToLimit   bool              `name:"set_memory_request_to_limit" default:"false"`
 }
 
 // MustMarshal marshals the config or panics