*: add pod disruption budget

api/v1alpha1/cluster_types.go

@@ -35,6 +35,12 @@ type ClusterSpec struct {
 	// +kubebuilder:default:=3
 	Replicas *int32 `json:"replicas,omitempty"`
 
+	// The number of pods from that set that must still be available after the
+	// eviction, even in the absence of the evicted pod
+	// +optional
+	// +kubebuilder:default:="50%"
+	MinAvailable string `json:"minAvailable,omitempty"`
+
 	// MysqlOpts is the options of MySQL container.
 	// +optional
 	// +kubebuilder:default:={rootPassword: "", rootHost: "127.0.0.1", user: "qc_usr", password: "Qing@123", database: "qingcloud", initTokuDB: true, resources: {limits: {cpu: "500m", memory: "1Gi"}, requests: {cpu: "100m", memory: "256Mi"}}}

charts/mysql-operator/crds/mysql.radondb.com_clusters.yaml

@@ -106,6 +106,11 @@ spec:
                         type: object
                     type: object
                 type: object
+              minAvailable:
+                default: 50%
+                description: The number of pods from that set that must still be available
+                  after the eviction, even in the absence of the evicted pod
+                type: string
               mysqlOpts:
                 default:
                   database: qingcloud

charts/mysql-operator/templates/cluster_rbac.yaml

@@ -99,6 +99,18 @@ rules:
   - get
   - patch
   - update
+- apiGroups:
+  - policy
+  resources:
+  - poddisruptionbudgets
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch
 - apiGroups:
   - rbac.authorization.k8s.io
   resources:

cluster/cluster.go

@@ -248,7 +248,7 @@ func (c *Cluster) EnsureVolumeClaimTemplates(schema *runtime.Scheme) ([]corev1.P
 // GetNameForResource returns the name of a resource from above
 func (c *Cluster) GetNameForResource(name utils.ResourceName) string {
 	switch name {
-	case utils.StatefulSet, utils.ConfigMap, utils.HeadlessSVC:
+	case utils.StatefulSet, utils.ConfigMap, utils.HeadlessSVC, utils.PodDisruptionBudget:
 		return fmt.Sprintf("%s-mysql", c.Name)
 	case utils.LeaderService:
 		return fmt.Sprintf("%s-leader", c.Name)

cluster/syncer/pdb.go

@@ -0,0 +1,49 @@
+/*
+Copyright 2021 RadonDB.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package syncer
+
+import (
+	"github.com/presslabs/controller-util/syncer"
+	policyv1beta1 "k8s.io/api/policy/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/intstr"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	"github.com/radondb/radondb-mysql-kubernetes/cluster"
+	"github.com/radondb/radondb-mysql-kubernetes/utils"
+)
+
+// NewPDBSyncer returns podDisruptionBudget syncer.
+func NewPDBSyncer(cli client.Client, c *cluster.Cluster) syncer.Interface {
+	pdb := &policyv1beta1.PodDisruptionBudget{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      c.GetNameForResource(utils.PodDisruptionBudget),
+			Namespace: c.Namespace,
+		},
+	}
+
+	return syncer.NewObjectSyncer("PDB", c.Unwrap(), pdb, cli, func() error {
+		if pdb.Spec.MinAvailable != nil {
+			// this mean that pdb is created and should return because spec is imutable
+			return nil
+		}
+		ma := intstr.FromString(c.Spec.MinAvailable)
+		pdb.Spec.MinAvailable = &ma
+		pdb.Spec.Selector = metav1.SetAsLabelSelector(c.GetSelectorLabels())
+		return nil
+	})
+}

cluster/syncer/rolebinding.go

@@ -39,7 +39,7 @@ func NewRoleBindingSyncer(cli client.Client, c *cluster.Cluster) syncer.Interfac
 			Labels:    c.GetLabels(),
 		},
 	}
-	return syncer.NewObjectSyncer("Role", c.Unwrap(), roleBinding, cli, func() error {
+	return syncer.NewObjectSyncer("RoleBinding", c.Unwrap(), roleBinding, cli, func() error {
 		roleBinding.RoleRef = rbacv1.RoleRef{
 			APIGroup: "rbac.authorization.k8s.io",
 			Kind:     "Role",

config/crd/bases/mysql.radondb.com_clusters.yaml

@@ -106,6 +106,11 @@ spec:
                         type: object
                     type: object
                 type: object
+              minAvailable:
+                default: 50%
+                description: The number of pods from that set that must still be available
+                  after the eviction, even in the absence of the evicted pod
+                type: string
               mysqlOpts:
                 default:
                   database: qingcloud

config/rbac/role.yaml

@@ -90,6 +90,18 @@ rules:
   - get
   - patch
   - update
+- apiGroups:
+  - policy
+  resources:
+  - poddisruptionbudgets
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch
 - apiGroups:
   - rbac.authorization.k8s.io
   resources:

controllers/cluster_controller.go

@@ -23,6 +23,7 @@ import (
 	"github.com/presslabs/controller-util/syncer"
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
+	policyv1beta1 "k8s.io/api/policy/v1beta1"
 	rbacv1 "k8s.io/api/rbac/v1"
 	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -52,6 +53,7 @@ type ClusterReconciler struct {
 // +kubebuilder:rbac:groups=core,resources=serviceaccounts,verbs=get;list;watch;create;update
 // +kubebuilder:rbac:groups=rbac.authorization.k8s.io,resources=roles;rolebindings,verbs=get;list;watch;create;update
 // +kubebuilder:rbac:groups=coordination.k8s.io,resources=leases,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups=policy,resources=poddisruptionbudgets,verbs=get;list;watch;create;update;patch;delete
 
 // Reconcile is part of the main kubernetes reconciliation loop which aims to
 // move the current state of the cluster closer to the desired state.
@@ -113,6 +115,7 @@ func (r *ClusterReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ct
 		clustersyncer.NewLeaderSVCSyncer(r.Client, instance),
 		clustersyncer.NewFollowerSVCSyncer(r.Client, instance),
 		clustersyncer.NewStatefulSetSyncer(r.Client, instance, cmRev, sctRev),
+		clustersyncer.NewPDBSyncer(r.Client, instance),
 	}
 
 	// run the syncers
@@ -136,5 +139,6 @@ func (r *ClusterReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		Owns(&rbacv1.RoleBinding{}).
 		Owns(&corev1.ServiceAccount{}).
 		Owns(&corev1.Secret{}).
+		Owns(&policyv1beta1.PodDisruptionBudget{}).
 		Complete(r)
 }

utils/constants.go

@@ -110,4 +110,6 @@ const (
 	RoleBinding ResourceName = "rolebinding"
 	// ServiceAccount is the alias of the serviceaccount resource.
 	ServiceAccount ResourceName = "service-account"
+	// PodDisruptionBudget is the name of pod disruption budget for the statefulset.
+	PodDisruptionBudget ResourceName = "pdb"
 )