feat: complete Kra admin backend migration

internal/data/database.go

@@ -30,8 +30,10 @@ func normalizedDriver(driver string) string {
 		return "sqlite"
 	case "oracle":
 		return "oracle"
-	default:
+	case "", "mysql":
 		return "mysql"
+	default:
+		return ""
 	}
 }
 
@@ -114,8 +116,11 @@ func openWithDriver(driver, dsn string) (*gorm.DB, error) {
 	}
 }
 
-func openDatabase(c *conf.Data_Database, create bool) (*gorm.DB, error) {
+func openDatabase(c *conf.Data_Database, create bool, template string) (*gorm.DB, error) {
 	driver := normalizedDriver(c.Driver)
+	if driver == "" {
+		return nil, fmt.Errorf("unsupported database driver %q", c.Driver)
+	}
 	if driver == "sqlite" {
 		dsn, err := databaseDSN(c, "")
 		if err != nil {
@@ -150,9 +155,15 @@ func openDatabase(c *conf.Data_Database, create bool) (*gorm.DB, error) {
 		case "mysql":
 			statement = "CREATE DATABASE IF NOT EXISTS `" + c.Name + "` CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci"
 		case "pgsql":
+			if template == "" {
+				template = "template0"
+			}
+			if !databaseNamePattern.MatchString(template) {
+				return nil, fmt.Errorf("invalid PostgreSQL template %q", template)
+			}
 			var count int64
 			if err = adminDB.Raw("SELECT count(*) FROM pg_database WHERE datname = ?", c.Name).Scan(&count).Error; err == nil && count == 0 {
-				statement = `CREATE DATABASE "` + c.Name + `"`
+				statement = `CREATE DATABASE "` + c.Name + `" TEMPLATE "` + template + `"`
 			}
 		case "mssql":
 			statement = "IF DB_ID(N'" + c.Name + "') IS NULL CREATE DATABASE [" + c.Name + "]"