chore: use shared MySQLClients (#183)

CONTRIBUTING.md

@@ -11,7 +11,6 @@ Run lint:
 golangci-lint run ./...
 ```
 
-
 # 2. Run mysql-operator
 
 ## 2.1. Local
@@ -238,6 +237,12 @@ docker rm -f $(docker ps | grep mysql | head -1 |awk '{print $1}')
 make test
 ```
 
+Run individual test
+
+```
+KUBEBUILDER_ASSETS="/Users/m.naka/Library/Application Support/io.kubebuilder.envtest/k8s/1.24.2-darwin-arm64" bin/ginkgo -skip-package=e2e --focus "Should have finalizer" --failFast ./...
+```
+
 ## 4.3. e2e
 
 ### 4.3.1. e2e (kind + skaffold + ginkgo + gomega)

README.md

@@ -9,9 +9,16 @@ This is a go-based Kubernetes operator built with [operator-sdk](https://sdk.ope
 - Go: 1.19
 ## Components
 
-- `MySQL`: MySQL cluster (holds credentials to connect to MySQL)
-- `MySQLUser`: MySQL user (`mysqlName` and `host`)
-- `MySQLDB`: MySQL database (`mysqlName` and `dbName`)
+![](diagram.drawio.svg)
+
+1. Custom Resource
+    1. `MySQL`: MySQL cluster (holds credentials to connect to MySQL)
+    1. `MySQLUser`: MySQL user (`mysqlName` and `host`)
+    1. `MySQLDB`: MySQL database (`mysqlName` and `dbName`)
+1. Reconciler
+    1. `MySQLReconciler` is responsible for updating `MySQLClients` based on `MySQL` resource
+    1. `MySQLUserReconciler` is responsible for managing `MySQLUser` using `MySQLClients`
+    1. `MySQLDBReconciler` is responsible for managing `MySQLDB` using `MySQLClients`
 
 ## Getting Started
 
@@ -88,8 +95,21 @@ This is a go-based Kubernetes operator built with [operator-sdk](https://sdk.ope
     kubectl delete -k https://github.com/nakamasato/mysql-operator/config/samples-on-k8s
     ```
 
-    NOTICE: custom resources might get stuck if MySQL is deleted before (to be improved). → Remove finalizers to forcifully delete the stuck objects
-    `kubectl patch mysqluser <resource_name> -p '{"metadata":{"finalizers": []}}' --type=merge` or `kubectl patch mysql <resource_name> -p '{"metadata":{"finalizers": []}}' --type=merge` (Bug: https://github.com/nakamasato/mysql-operator/issues/162)
+    <details><summary>NOTICE</summary>
+
+    custom resources might get stuck if MySQL is deleted before (to be improved). → Remove finalizers to forcifully delete the stuck objects:
+    ```
+    kubectl patch mysqluser <resource_name> -p '{"metadata":{"finalizers": []}}' --type=merge
+    ```
+    ```
+    kubectl patch mysql <resource_name> -p '{"metadata":{"finalizers": []}}' --type=merge
+    ```
+
+    ```
+    kubectl patch mysqldb <resource_name> -p '{"metadata":{"finalizers": []}}' --type=merge
+    ```
+
+    </details>
 
 1. (Optional) Delete MySQL
     ```

controllers/mysql_controller.go

@@ -18,6 +18,7 @@ package controllers
 
 import (
 	"context"
+	"database/sql"
 	"fmt"
 	"time"
 
@@ -29,14 +30,17 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/log"
 
 	mysqlv1alpha1 "github.com/nakamasato/mysql-operator/api/v1alpha1"
+	mysqlinternal "github.com/nakamasato/mysql-operator/internal/mysql"
 )
 
 const mysqlFinalizer = "mysql.nakamasato.com/finalizer"
 
 // MySQLReconciler reconciles a MySQL object
 type MySQLReconciler struct {
 	client.Client
-	Scheme *runtime.Scheme
+	Scheme          *runtime.Scheme
+	MySQLClients    mysqlinternal.MySQLClients
+	MySQLDriverName string
 }
 
 //+kubebuilder:rbac:groups=mysql.nakamasato.com,resources=mysqls,verbs=get;list;watch;create;update;patch;delete
@@ -68,6 +72,12 @@ func (r *MySQLReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl
 		log.Error(err, "[FetchMySQL] Failed to get MySQL")
 		return ctrl.Result{}, err
 	}
+
+	// Update MySQLClients
+	if err := r.UpdateMySQLClients(ctx, mysql); err != nil {
+		return ctrl.Result{}, err
+	}
+
 	// Add a finalizer if not exists
 	if controllerutil.AddFinalizer(mysql, mysqlFinalizer) {
 		if err := r.Update(ctx, mysql); err != nil {
@@ -123,6 +133,28 @@ func (r *MySQLReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		Complete(r)
 }
 
+func (r *MySQLReconciler) UpdateMySQLClients(ctx context.Context, mysql *mysqlv1alpha1.MySQL) error {
+	log := log.FromContext(ctx).WithName("MySQLReconciler")
+	if db, _ := r.MySQLClients.GetClient(mysql.Name); db != nil {
+		log.Info("MySQLClient already exists", "mysql.Name", mysql.Name)
+		return nil
+	}
+	// db, err := sql.Open("mysql", fmt.Sprintf("%s:%s@tpc(%s:%d)/", mysql.Spec.AdminUser, mysql.Spec.AdminPassword, mysql.Spec.Host, 3306))
+	db, err := sql.Open(r.MySQLDriverName, mysql.Spec.AdminUser+":"+mysql.Spec.AdminPassword+"@tcp("+mysql.Spec.Host+":3306)/")
+	if err != nil {
+		log.Error(err, "Failed to open MySQL database", "mysql.Name", mysql.Name)
+		return err
+	}
+	r.MySQLClients[mysql.Name] = db
+	err = db.PingContext(ctx)
+	if err != nil {
+		log.Error(err, "Ping failed", "mysql.Name", mysql.Name)
+		return err
+	}
+	log.Info("Successfully added MySQL client", "mysql.Name", mysql.Name)
+	return nil
+}
+
 func (r *MySQLReconciler) countReferencesByMySQLUser(ctx context.Context, mysql *mysqlv1alpha1.MySQL) (int, error) {
 	// 1. Get the referenced MySQLUser instances.
 	// 2. Return the number of referencing MySQLUser.
@@ -147,5 +179,17 @@ func (r *MySQLReconciler) countReferencesByMySQLDB(ctx context.Context, mysql *m
 
 // finalizeMySQL return true if no user and no db is referencing the given MySQL
 func (r *MySQLReconciler) finalizeMySQL(ctx context.Context, mysql *mysqlv1alpha1.MySQL) bool {
-	return mysql.Status.UserCount == 0 && mysql.Status.DBCount == 0
+	log := log.FromContext(ctx).WithName("MySQLReconciler")
+	if mysql.Status.UserCount > 0 || mysql.Status.DBCount > 0 {
+		log.Info("there's referencing user or database", "UserCount", mysql.Status.UserCount, "DBCount", mysql.Status.DBCount)
+		return false
+	}
+	if db, ok := r.MySQLClients[mysql.Name]; ok {
+		if err := db.Close(); err != nil {
+			return false
+		}
+		delete(r.MySQLClients, mysql.Name)
+	}
+	log.Info("Closed and removed MySQL client", "mysql.Name", mysql.Name)
+	return true
 }

controllers/mysql_controller_test.go

@@ -13,6 +13,7 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
 
 	mysqlv1alpha1 "github.com/nakamasato/mysql-operator/api/v1alpha1"
+	internalmysql "github.com/nakamasato/mysql-operator/internal/mysql"
 )
 
 var _ = Describe("MySQL controller", func() {
@@ -42,8 +43,10 @@ var _ = Describe("MySQL controller", func() {
 		}
 
 		err = (&MySQLReconciler{
-			Client: k8sManager.GetClient(),
-			Scheme: k8sManager.GetScheme(),
+			Client:          k8sManager.GetClient(),
+			Scheme:          k8sManager.GetScheme(),
+			MySQLClients:    internalmysql.MySQLClients{},
+			MySQLDriverName: "testdbdriver",
 		}).SetupWithManager(k8sManager)
 		Expect(err).ToNot(HaveOccurred())
 

controllers/mysqldb_controller.go

@@ -18,6 +18,8 @@ package controllers
 
 import (
 	"context"
+	"database/sql"
+	"fmt"
 	"time"
 
 	"k8s.io/apimachinery/pkg/api/errors"
@@ -43,8 +45,8 @@ const (
 // MySQLDBReconciler reconciles a MySQLDB object
 type MySQLDBReconciler struct {
 	client.Client
-	Scheme             *runtime.Scheme
-	MySQLClientFactory mysqlinternal.MySQLClientFactory
+	Scheme       *runtime.Scheme
+	MySQLClients mysqlinternal.MySQLClients
 }
 
 //+kubebuilder:rbac:groups=mysql.nakamasato.com,resources=mysqldbs,verbs=get;list;watch;create;update;patch;delete
@@ -82,38 +84,12 @@ func (r *MySQLDBReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ct
 		return ctrl.Result{}, err
 	}
 
-	// 3. Connect to MySQL
-	cfg := mysqlinternal.MySQLConfig{
-		AdminUser:     mysql.Spec.AdminUser,
-		AdminPassword: mysql.Spec.AdminPassword,
-		Host:          mysql.Spec.Host,
-	}
-	mysqlClient, err := r.MySQLClientFactory(cfg)
+	// 3. Get MySQL client
+	mysqlClient, err := r.MySQLClients.GetClient(db.Spec.MysqlName)
 	if err != nil {
-		db.Status.Phase = mysqlDBPhaseNotReady
-		db.Status.Reason = mysqlDBReasonMySQLConnectionFailed
-		if serr := r.Status().Update(ctx, db); serr != nil {
-			log.Error(serr, "Failed to update db status", "db", db.Name)
-		}
-		log.Error(err, "[MySQLClient] Failed to create")
-		return ctrl.Result{}, err // requeue
-	}
-	log.Info("[MySQLClient] Ping")
-	ctxPing, cancel := context.WithTimeout(ctx, time.Second)
-	defer cancel()
-	err = mysqlClient.PingContext(ctxPing)
-	if err != nil {
-		db.Status.Phase = mysqlDBPhaseNotReady
-		db.Status.Reason = mysqlDBReasonMySQLConnectionFailed
-		log.Error(err, "[MySQLClient] Failed to connect to MySQL", "mysqlName", mysql.Name)
-		if serr := r.Status().Update(ctx, db); serr != nil {
-			log.Error(serr, "Failed to update db status", "db", db.Name)
-			return ctrl.Result{RequeueAfter: time.Second}, nil
-		}
-		return ctrl.Result{RequeueAfter: time.Second}, nil // requeue after 1 second
+		log.Error(err, "Failed to get MySQL client", "mysqlName", db.Spec.MysqlName)
+		return ctrl.Result{}, err
 	}
-	log.Info("[MySQLClient] Successfully connected")
-	defer mysqlClient.Close()
 
 	// 4. Delete if NotFound with finalizer
 	if controllerutil.AddFinalizer(db, mysqlDBFinalizer) {
@@ -124,7 +100,7 @@ func (r *MySQLDBReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ct
 	}
 	if !db.GetDeletionTimestamp().IsZero() {
 		if controllerutil.ContainsFinalizer(db, mysqlDBFinalizer) {
-			if err := r.finalizeMySQLDB(ctx, db, mysql); err != nil {
+			if err := r.finalizeMySQLDB(ctx, mysqlClient, db); err != nil {
 				return ctrl.Result{}, err
 			}
 			if controllerutil.RemoveFinalizer(db, mysqlDBFinalizer) {
@@ -138,7 +114,7 @@ func (r *MySQLDBReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ct
 	}
 
 	// 5. Create if not exists
-	err = mysqlClient.Exec("CREATE DATABASE IF NOT EXISTS " + db.Spec.DBName + ";")
+	res, err := mysqlClient.ExecContext(ctx, fmt.Sprintf("CREATE DATABASE IF NOT EXISTS %s", db.Spec.DBName))
 	if err != nil {
 		log.Error(err, "[MySQL] Failed to create MySQL database.", "mysql", mysql.Name, "database", db.Spec.DBName)
 		db.Status.Phase = mysqlDBPhaseNotReady
@@ -149,34 +125,28 @@ func (r *MySQLDBReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ct
 		}
 		return ctrl.Result{}, err
 	}
-	db.Status.Phase = mysqlDBPhaseReady
-	db.Status.Reason = mysqlDBReasonCompleted
-	if serr := r.Status().Update(ctx, db); serr != nil {
-		log.Error(serr, "Failed to update MySQLDB status", "Name", db.Spec.DBName)
+	rows, err := res.RowsAffected()
+	if err != nil {
+		log.Error(err, "Failed to get res.RowsAffected")
+		return ctrl.Result{}, err
+	}
+	if rows > 0 {
+		db.Status.Phase = mysqlDBPhaseReady
+		db.Status.Reason = mysqlDBReasonCompleted
+		if serr := r.Status().Update(ctx, db); serr != nil {
+			log.Error(serr, "Failed to update MySQLDB status", "Name", db.Spec.DBName)
+		}
+	} else {
+		log.Info("database already exists", "database", db.Spec.DBName)
 	}
 
 	return ctrl.Result{}, nil
 }
 
 // finalizeMySQLDB drops MySQL database
-func (r *MySQLDBReconciler) finalizeMySQLDB(ctx context.Context, db *mysqlv1alpha1.MySQLDB, mysql *mysqlv1alpha1.MySQL) error {
-	mysqlClient, err := r.MySQLClientFactory(
-		mysqlinternal.MySQLConfig{
-			AdminUser:     mysql.Spec.AdminUser,
-			AdminPassword: mysql.Spec.AdminPassword,
-			Host:          mysql.Spec.Host,
-		})
-	if err != nil {
-		return err
-	}
-	ctxPing, cancel := context.WithTimeout(ctx, time.Second)
-	defer cancel()
-	err = mysqlClient.PingContext(ctxPing)
-	if err != nil {
-		return err
-	}
-	defer mysqlClient.Close()
-	return mysqlClient.Exec("DROP DATABASE IF EXISTS " + db.Spec.DBName + ";")
+func (r *MySQLDBReconciler) finalizeMySQLDB(ctx context.Context, mysqlClient *sql.DB, db *mysqlv1alpha1.MySQLDB) error {
+	_, err := mysqlClient.ExecContext(ctx, fmt.Sprintf("DROP DATABASE IF EXISTS %s", db.Spec.DBName))
+	return err
 }
 
 // SetupWithManager sets up the controller with the Manager.