gcfg 组件采用了接口化设计，以实现高扩展性。通过接口化设计的方式，使用者可以自定义对接的配置获取方式，例如 etcd, zookeeper, consul, kubernetes configmap, apollo 等等。

接口定义

https://github.com/gogf/gf/blob/master/os/gcfg/gcfg_adaper.go

// Adapter is the interface for configuration retrieving.
type Adapter interface {
    // Available checks and returns the configuration service is available.
    // The optional parameter `resource` specifies certain configuration resource.
    //
    // It returns true if configuration file is present in default AdapterFile, or else false.
    // Note that this function does not return error as it just does simply check for backend configuration service.
    Available(ctx context.Context, resource ...string) (ok bool)

    // Get retrieves and returns value by specified `pattern`.
    Get(ctx context.Context, pattern string) (value interface{}, err error)

    // Data retrieves and returns all configuration data as map type.
    // Note that this function may lead lots of memory usage if configuration data is too large,
    // you can implement this function if necessary.
    Data(ctx context.Context) (data map[string]interface{}, err error)
}

设置接口实现

配置对象可以通过 SetAdapter 方法设置当前使用的接口实现。

// SetAdapter sets the adapter of current Config object.
func (c *Config) SetAdapter(adapter Adapter)

获取接口实现

配置对象可以通过 GetAdapter 方法获取当前使用的接口实现。

// GetAdapter returns the adapter of current Config object.
func (c *Config) GetAdapter() Adapter