feat: optional MySQL/MariaDB database driver for deployments that cannot use local SQLite

internal/infrastructure/persistence/database/driver.go

@@ -8,9 +8,16 @@ import (
 	"gorm.io/gorm"
 )
 
+type PoolSettings struct {
+	MaxOpenConns    int
+	MaxIdleConns    int
+	ConnMaxLifetime time.Duration
+}
+
 type Config struct {
 	Driver string
 	Source string
+	Pool   *PoolSettings
 }
 
 type Driver interface {
@@ -20,6 +27,7 @@ type Driver interface {
 
 var drivers = map[string]Driver{
 	DriverSQLite: sqliteDriver{},
+	DriverMySQL:  mysqlDriver{},
 }
 
 type Connection struct {
@@ -36,9 +44,25 @@ func Connect(config Config) (*Connection, error) {
 	if err != nil {
 		return nil, err
 	}
+	if config.Pool != nil {
+		if err := applyPool(db, *config.Pool); err != nil {
+			return nil, err
+		}
+	}
 	return &Connection{DB: db, driver: driver}, nil
 }
 
+func applyPool(db *gorm.DB, pool PoolSettings) error {
+	sqlDb, err := db.DB()
+	if err != nil {
+		return err
+	}
+	sqlDb.SetMaxOpenConns(pool.MaxOpenConns)
+	sqlDb.SetMaxIdleConns(pool.MaxIdleConns)
+	sqlDb.SetConnMaxLifetime(pool.ConnMaxLifetime)
+	return nil
+}
+
 func (c *Connection) NewBackup(directory string, now func() time.Time) domainUpdate.DatabaseBackup {
 	return c.driver.NewBackup(c.DB, directory, now)
 }