signoz/pkg/config/conf.go

package config

import (
	"github.com/go-viper/mapstructure/v2"
	"github.com/knadh/koanf/providers/confmap"
	"github.com/knadh/koanf/v2"
)

const (
	KoanfDelimiter string = "::"
)

// Conf is a wrapper around the koanf library.
type Conf struct {
	*koanf.Koanf
}

// NewConf creates a new Conf instance.
func NewConf() *Conf {
	return &Conf{koanf.New(KoanfDelimiter)}
}

// NewConfFromMap creates a new Conf instance from a map.
func NewConfFromMap(m map[string]any) (*Conf, error) {
	conf := NewConf()
	if err := conf.Koanf.Load(confmap.Provider(m, KoanfDelimiter), nil); err != nil {
		return nil, err
	}

	return conf, nil
}

// MustNewConfFromMap creates a new Conf instance from a map.
// It panics if the conf cannot be created.
func MustNewConfFromMap(m map[string]any) *Conf {
	conf, err := NewConfFromMap(m)
	if err != nil {
		panic(err)
	}

	return conf
}

// Merge merges the current configuration with the input configuration.
func (conf *Conf) Merge(input *Conf) error {
	return conf.Koanf.Merge(input.Koanf)
}

// Merge merges the current configuration with the input configuration.
func (conf *Conf) MergeAt(input *Conf, path string) error {
	return conf.Koanf.MergeAt(input.Koanf, path)
}

// Unmarshal unmarshals the configuration at the given path into the input.
// It uses a WeaklyTypedInput to allow for more flexible unmarshalling.
func (conf *Conf) Unmarshal(path string, input any) error {
	dc := &mapstructure.DecoderConfig{
		TagName:          "mapstructure",
		WeaklyTypedInput: true,
		DecodeHook: mapstructure.ComposeDecodeHookFunc(
			mapstructure.StringToSliceHookFunc(","),
			mapstructure.StringToTimeDurationHookFunc(),
			mapstructure.TextUnmarshallerHookFunc(),
		),
		Result: input,
	}

	return conf.Koanf.UnmarshalWithConf(path, input, koanf.UnmarshalConf{Tag: "mapstructure", DecoderConfig: dc})
}

// Set sets the configuration at the given key.
// It decodes the input into a map as per mapstructure.Decode and then merges it into the configuration.
func (conf *Conf) Set(key string, input any) error {
	m := map[string]any{}
	err := mapstructure.Decode(input, &m)
	if err != nil {
		return err
	}

	newConf := NewConf()
	if err := newConf.Koanf.Load(confmap.Provider(m, KoanfDelimiter), nil); err != nil {
		return err
	}

	if err := conf.Koanf.MergeAt(newConf.Koanf, key); err != nil {
		return err
	}

	return nil
}