update configuration to include database connection settings and adjust connection management

.env.example

@@ -1,4 +1,12 @@
+# Server Settings
 PORT=8080
+
+# DB Settings
 DB_DSN=root:secret@tcp(127.0.0.1:3306)/emly?parseTime=true&loc=UTC
+MAX_OPEN_CONNS=25
+MAX_IDLE_CONNS=5
+CONN_MAX_LIFETIME=5m
+
+# API Keys
 API_KEY=key-one
 ADMIN_KEY=admin-key-one

internal/config/config.go

@@ -2,14 +2,18 @@ package config
 
 import (
 	"os"
+	"strconv"
 	"strings"
 )
 
 type Config struct {
-	Port     string
+	Port            string
-	DSN      string
+	DSN             string
-	APIKey   string
+	APIKey          string
-	AdminKey string
+	AdminKey        string
+	MaxOpenConns    int
+	MaxIdleConns    int
+	ConnMaxLifetime int
 }
 
 func Load() *Config {
@@ -38,10 +42,26 @@ func Load() *Config {
 		}
 	}
 
+	maxOpenConns, err := strconv.Atoi(os.Getenv("DB_MAX_OPEN_CONNS"))
+	if err != nil {
+		maxOpenConns = 30
+	}
+	maxIdleConns, err := strconv.Atoi(os.Getenv("DB_MAX_IDLE_CONNS"))
+	if err != nil {
+		maxIdleConns = 5
+	}
+	connMaxLifetime, err := strconv.Atoi(os.Getenv("DB_CONN_MAX_LIFETIME"))
+	if err != nil {
+		connMaxLifetime = 5
+	}
+
 	return &Config{
-		Port:     port,
+		Port:            port,
-		DSN:      os.Getenv("DB_DSN"),
+		DSN:             os.Getenv("DB_DSN"),
-		APIKey:   apiKey,
+		APIKey:          apiKey,
-		AdminKey: adminKey,
+		AdminKey:        adminKey,
+		MaxOpenConns:    maxOpenConns,
+		MaxIdleConns:    maxIdleConns,
+		ConnMaxLifetime: connMaxLifetime,
 	}
 }

internal/database/database.go

@@ -15,9 +15,9 @@ func Connect(cfg *config.Config) (*sqlx.DB, error) {
 		return nil, err
 	}
 
-	db.SetMaxOpenConns(25)
+	db.SetMaxOpenConns(cfg.MaxOpenConns)
-	db.SetMaxIdleConns(5)
+	db.SetMaxIdleConns(cfg.MaxIdleConns)
-	db.SetConnMaxLifetime(5 * time.Minute)
+	db.SetConnMaxLifetime(time.Duration(cfg.ConnMaxLifetime) * time.Minute)
 
 	return db, nil
 }