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Config Module for Tinh Tinh

The Config module for the Tinh Tinh framework provides flexible configuration management for Go applications. It supports loading environment variables from .env files and struct-based configs from YAML, with first-class integration for dependency injection and modular apps.

Features​

  • Load configuration from .env, .yaml, or .yml files
  • Strongly-typed config structs with tags for mapping, default values, and validation
  • Namespace-based config injection for multiple configs (e.g., database, cache)
  • Conditional module registration based on environment or custom logic
  • Supports default values and validation via struct tags
  • Seamless integration with Tinh Tinh modules and controllers

Installation​

go get -u github.com/tinh-tinh/config/v2

Quick Start​

1. Basic Usage with .env​

import "github.com/tinh-tinh/config/v2"

type AppConfig struct {
    NodeEnv   string        `mapstructure:"NODE_ENV"`
    Port      int           `mapstructure:"PORT"`
    ExpiresIn time.Duration `mapstructure:"EXPIRES_IN"`
    Log       bool          `mapstructure:"LOG"`
    Secret    string        `mapstructure:"SECRET"`
}

cfg, err := config.NewEnv[AppConfig](".env")
if err != nil {
    panic(err)
}
fmt.Println(cfg.Port)

2. Using with YAML​

type YamlConfig struct {
    Host string `yaml:"host"`
    Port int    `yaml:"port"`
}

cfg, err := config.NewYaml[YamlConfig]("config.yaml")
if err != nil {
    panic(err)
}
fmt.Println(cfg.Host)

Tinh Tinh Module Integration​

Register as a Global Config​

import "github.com/tinh-tinh/tinhtinh/v2/core"

appModule := core.NewModule(core.NewModuleOptions{
    Imports: []core.Modules{
        config.ForRoot[AppConfig](".env"),
    },
})

Inject Config Anywhere​

cfg := config.Inject[AppConfig](module)
fmt.Println(cfg.Port)

Namespaced Configs (Multiple Sources)​

type MysqlConfig struct {
    DBHost string `mapstructure:"MYSQL_DBHOST"`
    DBPort string `mapstructure:"MYSQL_DBPORT"`
}

type MongoConfig struct {
    DBHost string `mapstructure:"MONGO_DBHOST"`
    DBPort string `mapstructure:"MONGO_DBPORT"`
}

// Register namespaced configs
appModule := core.NewModule(core.NewModuleOptions{
    Imports: []core.Modules{
        config.ForFeature[MysqlConfig]("mysql"),
        config.ForFeature("mongo", func() *MongoConfig {
            return &MongoConfig{
                DBHost: os.Getenv("MONGO_DBHOST"),
                DBPort: os.Getenv("MONGO_DBPORT"),
            }
        }),
    },
})

// Usage in controller/service
mysqlCfg := config.InjectNamespace[MysqlConfig](module, "mysql")
mongoCfg := config.InjectNamespace[MongoConfig](module, "mongo")

Conditional Module Registration​

import "os"

// Register module only if an env var is set
mod := config.RegisterWhen(config.ForRoot[AppConfig](".env"), "NODE_ENV")

// Or by custom function
mod = config.RegisterWhen(config.ForRoot[AppConfig](".env"), func() bool {
    return os.Getenv("ENABLE_FEATURE") == "true"
})

Struct Tag Reference​

  • mapstructure:"ENV_VAR" — maps struct field to environment variable
  • default:"value" — sets default value if env is missing
  • validate:"..." — supports validation (e.g. required, isEmail)
  • yaml:"key" — for YAML files

Example:

type Config struct {
    NodeEnv string `mapstructure:"NODE_ENV" default:"production"`
}

Supported File Types​

Advanced: Raw Loading​

config.ForRootRaw(".env.example") // Load .env file globally (no struct)

Error Handling & Validation​

  • Returns errors when variables are missing, types are invalid, or validation fails.
  • Supports default values for missing environment variables.

Testing & Patterns​

See env_test.go and namespace_test.go for examples of real-world usage.

For more, see the source code.