micro/config/config.go
Vasiliy Tolstov ca9f6fb5eb config: add watcher interface
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2021-08-03 00:23:28 +03:00

64 lines
1.6 KiB
Go

// Package config is an interface for dynamic configuration.
package config
import (
"context"
"errors"
"time"
)
// DefaultConfig default config
var DefaultConfig Config = NewConfig()
// DefaultWatcherInterval default interval for poll changes
var DefaultWatcherInterval = 5 * time.Second
var (
// ErrCodecMissing is returned when codec needed and not specified
ErrCodecMissing = errors.New("codec missing")
// ErrInvalidStruct is returned when the target struct is invalid
ErrInvalidStruct = errors.New("invalid struct specified")
// ErrWatcherStopped is returned when source watcher has been stopped
ErrWatcherStopped = errors.New("watcher stopped")
)
// Config is an interface abstraction for dynamic configuration
type Config interface {
// Name returns name of config
Name() string
// Init the config
Init(opts ...Option) error
// Options in the config
Options() Options
// Load config from sources
Load(context.Context, ...LoadOption) error
// Save config to sources
Save(context.Context, ...SaveOption) error
// Watch a config for changes
Watch(context.Context, ...WatchOption) (Watcher, error)
// String returns config type name
String() string
}
// Watcher is the config watcher
type Watcher interface {
// Next blocks until update happens or error returned
Next() (map[string]interface{}, error)
// Stop stops watcher
Stop() error
}
// Load loads config from config sources
func Load(ctx context.Context, cs []Config, opts ...LoadOption) error {
var err error
for _, c := range cs {
if err = c.Init(); err != nil {
return err
}
if err = c.Load(ctx, opts...); err != nil {
return err
}
}
return nil
}