*: Support running single node. #361 (#584)

feat(singleNode): Support running single node. #361

api/v1alpha1/mysqlcluster_types.go

@@ -31,7 +31,7 @@ type MysqlClusterSpec struct {
 
 	// Replicas is the number of pods.
 	// +optional
-	// +kubebuilder:validation:Enum=0;2;3;5
+	// +kubebuilder:validation:Enum=0;1;2;3;5
 	// +kubebuilder:default:=3
 	Replicas *int32 `json:"replicas,omitempty"`
 

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

@@ -1277,6 +1277,7 @@ spec:
                 description: Replicas is the number of pods.
                 enum:
                 - 0
+                - 1
                 - 2
                 - 3
                 - 5

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

@@ -1277,6 +1277,7 @@ spec:
                 description: Replicas is the number of pods.
                 enum:
                 - 0
+                - 1
                 - 2
                 - 3
                 - 5

controllers/mysqlcluster_controller.go

@@ -38,6 +38,7 @@ import (
 	"github.com/radondb/radondb-mysql-kubernetes/internal"
 	"github.com/radondb/radondb-mysql-kubernetes/mysqlcluster"
 	clustersyncer "github.com/radondb/radondb-mysql-kubernetes/mysqlcluster/syncer"
+	"github.com/radondb/radondb-mysql-kubernetes/utils"
 )
 
 var clusterFinalizer string = "mysqlcluster-finalizer"
@@ -137,12 +138,23 @@ func (r *MysqlClusterReconciler) Reconcile(ctx context.Context, req ctrl.Request
 		clustersyncer.NewServiceAccountSyncer(r.Client, instance),
 		clustersyncer.NewHeadlessSVCSyncer(r.Client, instance),
 		clustersyncer.NewLeaderSVCSyncer(r.Client, instance),
-		clustersyncer.NewFollowerSVCSyncer(r.Client, instance),
-		clustersyncer.NewStatefulSetSyncer(r.Client, instance, cmRev, sctRev, r.SQLRunnerFactory, r.XenonExecutor),
-		clustersyncer.NewPDBSyncer(r.Client, instance),
-		clustersyncer.NewXenonCMSyncer(r.Client, instance),
 	}
-
+	if *instance.Unwrap().Spec.Replicas == 1 {
+		// Delete follower service
+		r.deleteFollowerService(ctx, req, instance.Unwrap())
+		syncers = append(syncers,
+			clustersyncer.NewStatefulSetSyncer(r.Client, instance, cmRev, sctRev, r.SQLRunnerFactory, r.XenonExecutor),
+			clustersyncer.NewPDBSyncer(r.Client, instance),
+			clustersyncer.NewXenonCMSyncer(r.Client, instance),
+		)
+	} else {
+		syncers = append(syncers,
+			clustersyncer.NewFollowerSVCSyncer(r.Client, instance),
+			clustersyncer.NewStatefulSetSyncer(r.Client, instance, cmRev, sctRev, r.SQLRunnerFactory, r.XenonExecutor),
+			clustersyncer.NewPDBSyncer(r.Client, instance),
+			clustersyncer.NewXenonCMSyncer(r.Client, instance),
+		)
+	}
 	if instance.Spec.MetricsOpts.Enabled {
 		syncers = append(syncers, clustersyncer.NewMetricsSVCSyncer(r.Client, instance))
 	}
@@ -204,3 +216,25 @@ func (r *MysqlClusterReconciler) deleteAllBackup(ctx context.Context, req ctrl.R
 
 	return nil
 }
+
+// For SingleNode, follower service do not need.
+func (r *MysqlClusterReconciler) deleteFollowerService(ctx context.Context, req ctrl.Request, instance *apiv1alpha1.MysqlCluster) error {
+	log := log.FromContext(ctx).WithName("controllers").WithName("MysqlCluster")
+	labelSet := labels.Set{"mysql.radondb.com/service-type": string(utils.FollowerService)}
+	serviceList := corev1.ServiceList{}
+	if err := r.List(ctx,
+		&serviceList,
+		&client.ListOptions{
+			Namespace:     instance.Namespace,
+			LabelSelector: labelSet.AsSelector(),
+		},
+	); err != nil {
+		return err
+	}
+	for _, svc := range serviceList.Items {
+		if err := r.Delete(context.TODO(), &svc); err != nil {
+			log.Error(err, "failed to delete a backup", "backup", svc)
+		}
+	}
+	return nil
+}

mysqlcluster/container/xenon.go

@@ -43,7 +43,11 @@ func (c *xenon) getImage() string {
 
 // getCommand get the container command.
 func (c *xenon) getCommand() []string {
-	return nil
+	if *c.Spec.Replicas == 1 {
+		return []string{"xenon", "-c", "/etc/xenon/xenon.json", "-r", "LEADER"}
+	}
+	// If return nil, statefulset never update command , And I don't know why.
+	return []string{"xenon", "-c", "/etc/xenon/xenon.json"}
 }
 
 // getEnvVars get the container env.

mysqlcluster/container/xenon_test.go

@@ -64,7 +64,7 @@ func TestGetXenonImage(t *testing.T) {
 }
 
 func TestGetXenonCommand(t *testing.T) {
-	assert.Nil(t, xenonCase.Command)
+	assert.Equal(t, []string{"xenon", "-c", "/etc/xenon/xenon.json"}, xenonCase.Command)
 }
 
 func TestGetXenonEnvVar(t *testing.T) {