Add "init_config" option to mysqlctl.

Author: jvaidya

go/cmd/mysqlctl/mysqlctl.go

@@ -50,6 +50,21 @@ const (
 	dbconfigFlags = dbconfigs.DbaConfig
 )
 
+func initConfigCmd(subFlags *flag.FlagSet, args []string) error {
+	subFlags.Parse(args)
+
+	// Generate my.cnf from scratch and use it to find mysqld.
+	mysqld, err := mysqlctl.CreateMysqld(uint32(*tabletUID), *mysqlSocket, int32(*mysqlPort), dbconfigFlags)
+	if err != nil {
+		return fmt.Errorf("failed to initialize mysql config: %v", err)
+	}
+	defer mysqld.Close()
+	if err := mysqld.InitConfig(); err != nil {
+		return fmt.Errorf("failed to init mysql config: %v", err)
+	}
+	return nil
+}
+
 func initCmd(subFlags *flag.FlagSet, args []string) error {
 	waitTime := subFlags.Duration("wait_time", 5*time.Minute, "how long to wait for startup")
 	initDBSQLFile := subFlags.String("init_db_sql_file", "", "path to .sql file to run after mysql_install_db")
@@ -189,6 +204,8 @@ type command struct {
 var commands = []command{
 	{"init", initCmd, "[-wait_time=5m] [-init_db_sql_file=]",
 		"Initalizes the directory structure and starts mysqld"},
+	{"init_config", initConfigCmd, "",
+		"Initalizes the directory structure, creates my.cnf file, but does not start mysqld"},
 	{"reinit_config", reinitConfigCmd, "",
 		"Reinitalizes my.cnf file with new server_id"},
 	{"teardown", teardownCmd, "[-wait_time=5m] [-force]",

go/vt/mysqlctl/mysqld.go

@@ -466,11 +466,10 @@ func binaryPath(root, binary string) (string, error) {
 		binary, root, strings.Join(subdirs, ","))
 }
 
-// Init will create the default directory structure for the mysqld process,
-// generate / configure a my.cnf file, install a skeleton database,
-// and apply the provided initial SQL file.
-func (mysqld *Mysqld) Init(ctx context.Context, initDBSQLFile string) error {
-	log.Infof("mysqlctl.Init")
+// InitConfig will create the default directory structure for the mysqld process,
+// generate / configure a my.cnf file.
+func (mysqld *Mysqld) InitConfig() error {
+	log.Infof("mysqlctl.InitConfig")
 	err := mysqld.createDirs()
 	if err != nil {
 		log.Errorf("%s", err.Error())
@@ -487,7 +486,19 @@ func (mysqld *Mysqld) Init(ctx context.Context, initDBSQLFile string) error {
 		log.Errorf("failed creating %v: %v", mysqld.config.path, err)
 		return err
 	}
+	return nil
+}
 
+// Init will create the default directory structure for the mysqld process,
+// generate / configure a my.cnf file install a skeleton database,
+// and apply the provided initial SQL file.
+func (mysqld *Mysqld) Init(ctx context.Context, initDBSQLFile string) error {
+	log.Infof("mysqlctl.Init")
+	err := mysqld.InitConfig()
+	if err != nil {
+		log.Errorf("%s", err.Error())
+		return err
+	}
 	// Install data dir.
 	if err = mysqld.installDataDir(); err != nil {
 		return err