feat: add logging and collector implementations

- Introduced `hertzx` package with `NewHertz` function for server initialization.
- Implemented `logx` package with various log collectors: Console, Loki, Elasticsearch, and Prometheus.
- Added `Logger` struct to manage logging levels and collectors.
- Created environment variable loading functionality in `osx` package to support configuration.
- Enhanced logging capabilities with structured log entries and asynchronous collection.

dbx/mysql.go

@@ -0,0 +1,71 @@
+package dbx
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"gorm.io/driver/mysql"
+	"gorm.io/gorm"
+)
+
+func GetMySQLDB(cfg *DBConfig, dbName string) *gorm.DB {
+	db, err := getMySQLInstance(cfg, dbName)
+	if err != nil {
+		panic("failed to connect to MySQL database: " + err.Error())
+	}
+	return db
+}
+
+func getMySQLInstance(cfg *DBConfig, dbName string) (*gorm.DB, error) {
+	targetDSN := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=utf8mb4&parseTime=True&loc=Local",
+		cfg.User, cfg.Password, cfg.Host, cfg.Port, dbName)
+
+	// 先尝试直接连接目标库
+	if db, err := gorm.Open(mysql.Open(targetDSN), &gorm.Config{}); err == nil {
+		return db, nil
+	}
+
+	// 以不指定数据库的 DSN 连接（用于创建数据库）
+	adminDSN := fmt.Sprintf("%s:%s@tcp(%s:%s)/?charset=utf8mb4&parseTime=True&loc=Local",
+		cfg.User, cfg.Password, cfg.Host, cfg.Port)
+	adminDB, err := gorm.Open(mysql.Open(adminDSN), &gorm.Config{})
+	if err != nil {
+		return nil, fmt.Errorf("connect admin mysql failed: %w", err)
+	}
+	// 关闭底层连接
+	if sqlDB, e := adminDB.DB(); e == nil {
+		defer sqlDB.Close()
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	// 检查是否存在（使用 INFORMATION_SCHEMA）
+	var count int64
+	checkSQL := "SELECT count(*) FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = ?"
+	if err := adminDB.WithContext(ctx).Raw(checkSQL, dbName).Scan(&count).Error; err != nil {
+		return nil, fmt.Errorf("check mysql database existence failed: %w", err)
+	}
+	if count == 0 {
+		ident := escapeMySQLIdentifier(dbName)
+		createSQL := fmt.Sprintf("CREATE DATABASE %s DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci", ident)
+		if err := adminDB.WithContext(ctx).Exec(createSQL).Error; err != nil {
+			return nil, fmt.Errorf("create mysql database %s failed: %w", dbName, err)
+		}
+	}
+
+	// 重试连接目标数据库
+	db2, err := gorm.Open(mysql.Open(targetDSN), &gorm.Config{})
+	if err != nil {
+		return nil, fmt.Errorf("connect mysql target after create failed: %w", err)
+	}
+	return db2, nil
+}
+
+// 辅助：安全转义 MySQL 标识符（用反引号并把 ` 替换为 “）
+func escapeMySQLIdentifier(s string) string {
+	s = strings.ReplaceAll(s, "`", "``")
+	return "`" + s + "`"
+}