Merge pull request #99 from cybozu-go/add-pdb

create PodDisruptionBudget
cybozu-go · Nov 4, 2020 · dc86d17 · dc86d17
2 parents 03b1206 + 86078ca
commit dc86d17
Show file tree

Hide file tree

Showing 3 changed files with 132 additions and 0 deletions.
diff --git a/config/rbac/role.yaml b/config/rbac/role.yaml
@@ -159,3 +159,13 @@ rules:
   - get
   - patch
   - update
+- apiGroups:
+  - policy
+  resources:
+  - poddisruptionbudgets
+  verbs:
+  - create
+  - get
+  - list
+  - update
+  - watch
diff --git a/controllers/mysqlcluster_controller.go b/controllers/mysqlcluster_controller.go
@@ -19,11 +19,13 @@ import (
 	appsv1 "k8s.io/api/apps/v1"
 	batchv1beta1 "k8s.io/api/batch/v1beta1"
 	corev1 "k8s.io/api/core/v1"
+	policyv1beta1 "k8s.io/api/policy/v1beta1"
 	"k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/intstr"
 	"k8s.io/client-go/tools/record"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
@@ -86,6 +88,7 @@ type MySQLClusterReconciler struct {
 // +kubebuilder:rbac:groups="batch",resources=cronjobs,verbs=get;list;watch;create;update;patch;delete
 // +kubebuilder:rbac:groups="batch",resources=cronjobs/status,verbs=get
 // +kubebuilder:rbac:groups="",resources=events,verbs=get;list;watch;create;patch
+// +kubebuilder:rbac:groups="policy",resources=poddisruptionbudgets,verbs=get;list;watch;create;update
 
 // Reconcile reconciles MySQLCluster.
 func (r *MySQLClusterReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
@@ -232,6 +235,12 @@ func (r *MySQLClusterReconciler) reconcileInitialize(ctx context.Context, log lo
 		return false, err
 	}
 
+	isUpdated, err = r.createOrUpdatePodDisruptionBudget(ctx, log, cluster)
+	isUpdatedAtLeastOnce = isUpdatedAtLeastOnce || isUpdated
+	if err != nil {
+		return false, err
+	}
+
 	return isUpdatedAtLeastOnce, nil
 }
 
@@ -264,6 +273,7 @@ func (r *MySQLClusterReconciler) SetupWithManager(mgr ctrl.Manager, watcherInter
 		Owns(&corev1.ServiceAccount{}).
 		Owns(&corev1.ConfigMap{}).
 		Owns(&batchv1beta1.CronJob{}).
+		Owns(&policyv1beta1.PodDisruptionBudget{}).
 		Watches(&src, &handler.EnqueueRequestForObject{}).
 		WithOptions(
 			controller.Options{MaxConcurrentReconciles: 8},
@@ -1121,6 +1131,43 @@ func (r *MySQLClusterReconciler) createOrUpdateService(ctx context.Context, clus
 	return isUpdated, nil
 }
 
+func (r *MySQLClusterReconciler) createOrUpdatePodDisruptionBudget(ctx context.Context, log logr.Logger, cluster *mocov1alpha1.MySQLCluster) (bool, error) {
+	isUpdated := false
+
+	pdb := &policyv1beta1.PodDisruptionBudget{}
+	pdb.SetNamespace(cluster.Namespace)
+	pdb.SetName(moco.UniqueName(cluster))
+
+	op, err := ctrl.CreateOrUpdate(ctx, r.Client, pdb, func() error {
+		setStandardLabels(&pdb.ObjectMeta, cluster)
+		pdb.Spec.MaxUnavailable = &intstr.IntOrString{}
+		pdb.Spec.MaxUnavailable.Type = intstr.Int
+		if cluster.Spec.Replicas > 1 {
+			pdb.Spec.MaxUnavailable.IntVal = cluster.Spec.Replicas / 2
+		} else {
+			pdb.Spec.MaxUnavailable.IntVal = 1
+		}
+		pdb.Spec.Selector = &metav1.LabelSelector{}
+		pdb.Spec.Selector.MatchLabels = map[string]string{
+			moco.ClusterKey:   moco.UniqueName(cluster),
+			moco.ManagedByKey: moco.MyName,
+			moco.AppNameKey:   moco.AppName,
+		}
+
+		return ctrl.SetControllerReference(cluster, pdb, r.Scheme)
+	})
+	if err != nil {
+		log.Error(err, "unable to create-or-update PodDisruptionBudget")
+		return false, err
+	}
+	if op != controllerutil.OperationResultNone {
+		log.Info("reconcile PodDisruptionBudget successfully", "op", op)
+		isUpdated = true
+	}
+
+	return isUpdated, nil
+}
+
 func (r *MySQLClusterReconciler) generateAgentToken(ctx context.Context, log logr.Logger, cluster *mocov1alpha1.MySQLCluster) (bool, error) {
 	if len(cluster.Status.AgentToken) != 0 {
 		return false, nil

diff --git a/controllers/mysqlcluster_controller_test.go b/controllers/mysqlcluster_controller_test.go
@@ -15,6 +15,7 @@ import (
 	appsv1 "k8s.io/api/apps/v1"
 	batchv1beta1 "k8s.io/api/batch/v1beta1"
 	corev1 "k8s.io/api/core/v1"
+	policyv1beta1 "k8s.io/api/policy/v1beta1"
 	k8serror "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -737,4 +738,78 @@ var _ = Describe("MySQLCluster controller", func() {
 			Expect(isUpdated).Should(BeFalse())
 		})
 	})
+
+	Context("PodDisruptionBudget", func() {
+		It("should create pod disruption budget", func() {
+			expectedSpec := policyv1beta1.PodDisruptionBudgetSpec{
+				MaxUnavailable: &intstr.IntOrString{
+					Type:   intstr.Int,
+					IntVal: 1,
+				},
+				Selector: &metav1.LabelSelector{
+					MatchLabels: map[string]string{
+						moco.ClusterKey:   moco.UniqueName(cluster),
+						moco.AppNameKey:   moco.AppName,
+						moco.ManagedByKey: moco.MyName,
+					},
+				},
+			}
+
+			cluster.Spec.Replicas = 1
+
+			isUpdated, err := reconciler.createOrUpdatePodDisruptionBudget(ctx, reconciler.Log, cluster)
+			Expect(err).ShouldNot(HaveOccurred())
+			Expect(isUpdated).Should(BeTrue())
+
+			pdb := &policyv1beta1.PodDisruptionBudget{}
+			err = k8sClient.Get(ctx, client.ObjectKey{Name: moco.UniqueName(cluster), Namespace: cluster.Namespace}, pdb)
+			Expect(err).ShouldNot(HaveOccurred())
+
+			Expect(pdb.Spec).Should(Equal(expectedSpec))
+
+			isUpdated, err = reconciler.createOrUpdatePodDisruptionBudget(ctx, reconciler.Log, cluster)
+			Expect(err).ShouldNot(HaveOccurred())
+			Expect(isUpdated).Should(BeFalse())
+		})
+
+		It("should fill appropriate MaxUnavailable", func() {
+			expectedSpec := policyv1beta1.PodDisruptionBudgetSpec{
+				MaxUnavailable: &intstr.IntOrString{
+					Type:   intstr.Int,
+					IntVal: 1,
+				},
+				Selector: &metav1.LabelSelector{
+					MatchLabels: map[string]string{
+						moco.ClusterKey:   moco.UniqueName(cluster),
+						moco.AppNameKey:   moco.AppName,
+						moco.ManagedByKey: moco.MyName,
+					},
+				},
+			}
+
+			By("checking in case of 5 replicas")
+			cluster.Spec.Replicas = 5
+			isUpdated, err := reconciler.createOrUpdatePodDisruptionBudget(ctx, reconciler.Log, cluster)
+			Expect(err).ShouldNot(HaveOccurred())
+			Expect(isUpdated).Should(BeTrue())
+
+			pdb := &policyv1beta1.PodDisruptionBudget{}
+			err = k8sClient.Get(ctx, client.ObjectKey{Name: moco.UniqueName(cluster), Namespace: cluster.Namespace}, pdb)
+			Expect(err).ShouldNot(HaveOccurred())
+			expectedSpec.MaxUnavailable.IntVal = 2
+			Expect(pdb.Spec).Should(Equal(expectedSpec))
+
+			By("checking in case of 3 replicas")
+			cluster.Spec.Replicas = 3
+			isUpdated, err = reconciler.createOrUpdatePodDisruptionBudget(ctx, reconciler.Log, cluster)
+			Expect(err).ShouldNot(HaveOccurred())
+			Expect(isUpdated).Should(BeTrue())
+
+			pdb = &policyv1beta1.PodDisruptionBudget{}
+			err = k8sClient.Get(ctx, client.ObjectKey{Name: moco.UniqueName(cluster), Namespace: cluster.Namespace}, pdb)
+			Expect(err).ShouldNot(HaveOccurred())
+			expectedSpec.MaxUnavailable.IntVal = 1
+			Expect(pdb.Spec).Should(Equal(expectedSpec))
+		})
+	})
 })