Make DROP/CREATE DATABASE pluggable

go/test/endtoend/vtgate/createdb_plugin/main_test.go

@@ -0,0 +1,189 @@
+/*
+Copyright 2020 The Vitess Authors.
+
+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 unsharded
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"os"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/stretchr/testify/require"
+
+	"vitess.io/vitess/go/mysql"
+	"vitess.io/vitess/go/sqltypes"
+	"vitess.io/vitess/go/test/endtoend/cluster"
+)
+
+var (
+	clusterInstance *cluster.LocalProcessCluster
+	vtParams        mysql.ConnParams
+	keyspaceName    = "ks"
+	cell            = "zone1"
+	hostname        = "localhost"
+)
+
+func TestMain(m *testing.M) {
+	defer cluster.PanicHandler(nil)
+	flag.Parse()
+
+	exitCode := func() int {
+		clusterInstance = cluster.NewCluster(cell, hostname)
+		defer clusterInstance.Teardown()
+
+		// Start topo server
+		if err := clusterInstance.StartTopo(); err != nil {
+			return 1
+		}
+
+		// Start keyspace
+		keyspace := &cluster.Keyspace{
+			Name: keyspaceName,
+		}
+		if err := clusterInstance.StartKeyspace(*keyspace, []string{"-80", "80-"}, 0, false); err != nil {
+			return 1
+		}
+
+		// Start vtgate
+		clusterInstance.VtGateExtraArgs = []string{"-dbddl_plugin", "noop", "-mysql_server_query_timeout", "60s"}
+		vtgateProcess := clusterInstance.NewVtgateInstance()
+		vtgateProcess.SysVarSetEnabled = true
+		if err := vtgateProcess.Setup(); err != nil {
+			return 1
+		}
+
+		vtParams = mysql.ConnParams{
+			Host: clusterInstance.Hostname,
+			Port: clusterInstance.VtgateMySQLPort,
+		}
+		return m.Run()
+	}()
+	os.Exit(exitCode)
+}
+
+func TestDBDDLPlugin(t *testing.T) {
+	defer cluster.PanicHandler(t)
+	ctx := context.Background()
+	vtParams := mysql.ConnParams{
+		Host: "localhost",
+		Port: clusterInstance.VtgateMySQLPort,
+	}
+	conn, err := mysql.Connect(ctx, &vtParams)
+	require.NoError(t, err)
+	defer conn.Close()
+
+	createAndDrop := func(t *testing.T) {
+		wg := sync.WaitGroup{}
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			qr := exec(t, conn, `create database aaa`)
+			require.EqualValues(t, 1, qr.RowsAffected)
+		}()
+		time.Sleep(300 * time.Millisecond)
+		start(t, "aaa")
+
+		// wait until the create database query has returned
+		wg.Wait()
+
+		exec(t, conn, `use aaa`)
+		exec(t, conn, `create table t (id bigint primary key)`)
+		exec(t, conn, `insert into t(id) values (1),(2),(3),(4),(5)`)
+		assertMatches(t, conn, "select count(*) from t", `[[INT64(5)]]`)
+
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			_ = exec(t, conn, `drop database aaa`)
+		}()
+		time.Sleep(300 * time.Millisecond)
+		shutdown(t, "aaa")
+
+		// wait until the drop database query has returned
+		wg.Wait()
+
+		_, err = conn.ExecuteFetch(`select count(*) from t`, 1000, true)
+		require.Error(t, err)
+	}
+	t.Run("first try", func(t *testing.T) {
+		createAndDrop(t)
+	})
+	if !t.Failed() {
+		t.Run("second try", func(t *testing.T) {
+			createAndDrop(t)
+		})
+	}
+}
+
+func start(t *testing.T, ksName string) {
+	keyspace := &cluster.Keyspace{
+		Name: ksName,
+	}
+	require.NoError(t,
+		clusterInstance.StartUnshardedKeyspace(*keyspace, 0, false),
+		"new database creation failed")
+}
+
+func shutdown(t *testing.T, ksName string) {
+	for _, ks := range clusterInstance.Keyspaces {
+		if ks.Name != ksName {
+			continue
+		}
+		for _, shard := range ks.Shards {
+			for _, tablet := range shard.Vttablets {
+				if tablet.MysqlctlProcess.TabletUID > 0 {
+					_, err := tablet.MysqlctlProcess.StopProcess()
+					assert.NoError(t, err)
+				}
+				if tablet.MysqlctldProcess.TabletUID > 0 {
+					err := tablet.MysqlctldProcess.Stop()
+					assert.NoError(t, err)
+				}
+				_ = tablet.VttabletProcess.TearDown()
+			}
+		}
+	}
+
+	require.NoError(t,
+		clusterInstance.VtctlclientProcess.ExecuteCommand("DeleteKeyspace", "-recursive", ksName))
+
+	require.NoError(t,
+		clusterInstance.VtctlclientProcess.ExecuteCommand("RebuildVSchemaGraph"))
+}
+
+func exec(t *testing.T, conn *mysql.Conn, query string) *sqltypes.Result {
+	t.Helper()
+	qr, err := conn.ExecuteFetch(query, 1000, true)
+	require.NoError(t, err)
+	return qr
+}
+
+func assertMatches(t *testing.T, conn *mysql.Conn, query, expected string) {
+	t.Helper()
+	qr := exec(t, conn, query)
+	got := fmt.Sprintf("%v", qr.Rows)
+	diff := cmp.Diff(expected, got)
+	if diff != "" {
+		t.Errorf("Query: %s (-want +got):\n%s", query, diff)
+	}
+}

go/vt/sqlparser/ast.go

@@ -17,7 +17,6 @@ limitations under the License.
 package sqlparser
 
 import (
-	"fmt"
 	"strings"
 
 	"vitess.io/vitess/go/sqltypes"
@@ -343,6 +342,7 @@ type (
 
 	// DropDatabase represents a DROP database statement.
 	DropDatabase struct {
+		Comments Comments
 		DBName   string
 		IfExists bool
 	}
@@ -359,6 +359,7 @@ type (
 
 	// CreateDatabase represents a CREATE database statement.
 	CreateDatabase struct {
+		Comments      Comments
 		DBName        string
 		IfNotExists   bool
 		CreateOptions []CollateAndCharset
@@ -2039,9 +2040,9 @@ func (node *SetTransaction) Format(buf *TrackedBuffer) {
 func (node *DropDatabase) Format(buf *TrackedBuffer) {
 	exists := ""
 	if node.IfExists {
-		exists = " if exists"
+		exists = "if exists "
 	}
-	buf.WriteString(fmt.Sprintf("%s database%s %v", DropStr, exists, node.DBName))
+	buf.astPrintf(node, "%s database %v%s%s", DropStr, node.Comments, exists, node.DBName)
 }
 
 // Format formats the node.
@@ -3204,11 +3205,11 @@ func (node *SelectInto) Format(buf *TrackedBuffer) {
 
 // Format formats the node.
 func (node *CreateDatabase) Format(buf *TrackedBuffer) {
-	buf.WriteString("create database")
+	buf.astPrintf(node, "create database %v", node.Comments)
 	if node.IfNotExists {
-		buf.WriteString(" if not exists")
+		buf.WriteString("if not exists ")
 	}
-	buf.astPrintf(node, " %s", node.DBName)
+	buf.astPrintf(node, "%s", node.DBName)
 	if node.CreateOptions != nil {
 		for _, createOption := range node.CreateOptions {
 			if createOption.IsDefault {

go/vt/sqlparser/parse_test.go

@@ -1764,12 +1764,12 @@ var (
 	}, {
 		input: "rollback",
 	}, {
-		input: "create database test_db",
+		input: "create database /* simple */ test_db",
 	}, {
 		input:  "create schema test_db",
 		output: "create database test_db",
 	}, {
-		input: "create database if not exists test_db",
+		input: "create database /* simple */ if not exists test_db",
 	}, {
 		input:  "create schema if not exists test_db",
 		output: "create database if not exists test_db",
@@ -1785,12 +1785,12 @@ var (
 		input:  "CREATE DATABASE /*!32312 IF NOT EXISTS*/ `mysql` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N' */;",
 		output: "create database if not exists mysql default character set utf8mb4 collate utf8mb4_0900_ai_ci",
 	}, {
-		input: "drop database test_db",
+		input: "drop database /* simple */ test_db",
 	}, {
 		input:  "drop schema test_db",
 		output: "drop database test_db",
 	}, {
-		input: "drop database if exists test_db",
+		input: "drop database /* simple */ if exists test_db",
 	}, {
 		input:  "delete a.*, b.* from tbl_a a, tbl_b b where a.id = b.id and b.name = 'test'",
 		output: "delete a, b from tbl_a as a, tbl_b as b where a.id = b.id and b.`name` = 'test'",