Refactor database initialization to use a configuration struct for improved connection management

cmd/start.go

@@ -34,7 +34,8 @@ var startCmd = &cobra.Command{
 
 		// Database Setup
 		dbDSN := viper.GetString("db-dsn")
-		database, err := db.NewDB(ctx, logger, dbDSN)
+		dbConfig := db.DefaultDBConfig(dbDSN)
+		database, err := db.NewDB(ctx, logger, dbConfig)
 		if err != nil {
 			logger.Error("failed to initialize database", slog.Any("error", err))
 			os.Exit(1)

internal/db/database.go

@@ -8,6 +8,7 @@ import (
 	"log/slog"
 	"os"
 	"path/filepath"
+	"time"
 
 	_ "github.com/mattn/go-sqlite3" // SQLite driver
 )
@@ -17,30 +18,56 @@ var ddl string
 
 // DBConfig holds database configuration.
 type DBConfig struct {
-	DSN string // Data Source Name for SQLite
+	DSN             string        // Data Source Name for SQLite
+	MaxOpenConns    int           // Maximum number of open connections
+	MaxIdleConns    int           // Maximum number of idle connections
+	ConnMaxLifetime time.Duration // Maximum lifetime of connections
+	ConnMaxIdleTime time.Duration // Maximum idle time for connections
+}
+
+// DefaultDBConfig returns a DBConfig with sensible defaults for SQLite.
+func DefaultDBConfig(dsn string) *DBConfig {
+	return &DBConfig{
+		DSN:             dsn,
+		MaxOpenConns:    25,               // SQLite performs better with limited connections
+		MaxIdleConns:    10,               // Keep some connections idle for reuse
+		ConnMaxLifetime: 30 * time.Minute, // Rotate connections every 30 minutes
+		ConnMaxIdleTime: 5 * time.Minute,  // Close idle connections after 5 minutes
+	}
 }
 
 // NewDB initializes and returns a new database connection pool and runs migrations.
-func NewDB(ctx context.Context, logger *slog.Logger, dsn string) (*sql.DB, error) {
+func NewDB(ctx context.Context, logger *slog.Logger, config *DBConfig) (*sql.DB, error) {
 	// Ensure the directory for the SQLite file exists
-	dbDir := filepath.Dir(dsn)
+	dbDir := filepath.Dir(config.DSN)
 	if err := os.MkdirAll(dbDir, 0755); err != nil {
 		return nil, fmt.Errorf("failed to create database directory %s: %w", dbDir, err)
 	}
 
-	db, err := sql.Open("sqlite3", dsn+"?_foreign_keys=on") // Enable foreign key constraints
+	db, err := sql.Open("sqlite3", config.DSN+"?_foreign_keys=on") // Enable foreign key constraints
 	if err != nil {
 		return nil, fmt.Errorf("failed to open database: %w", err)
 	}
 
+	// Configure connection pool
+	db.SetMaxOpenConns(config.MaxOpenConns)
+	db.SetMaxIdleConns(config.MaxIdleConns)
+	db.SetConnMaxLifetime(config.ConnMaxLifetime)
+	db.SetConnMaxIdleTime(config.ConnMaxIdleTime)
+
 	if err = db.PingContext(ctx); err != nil {
+		db.Close() // Clean up connection on failure
 		return nil, fmt.Errorf("failed to ping database: %w", err)
 	}
 
-	logger.Info("database connection established", slog.String("dsn", dsn))
+	logger.Info("database connection established",
+		slog.String("dsn", config.DSN),
+		slog.Int("max_open_conns", config.MaxOpenConns),
+		slog.Int("max_idle_conns", config.MaxIdleConns))
 
 	// Execute schema.
 	if _, err := db.ExecContext(ctx, ddl); err != nil {
+		db.Close() // Clean up connection on failure
 		return nil, fmt.Errorf("failed to execute DDL: %w", err)
 	}
 	logger.Info("database schema applied")