config

README

Config

Config is a pluggable dynamic config package

Most config in applications are statically configured or include complex logic to load from multiple sources. Go Config makes this easy, pluggable and mergeable. You'll never have to deal with config in the same way again.

Features

• Dynamic Loading - Load configuration from multiple source as and when needed. Go Config manages watching config sources in the background and automatically merges and updates an in memory view.

• Pluggable Sources - Choose from any number of sources to load and merge config. The backend source is abstracted away into a standard format consumed internally and decoded via encoders. Sources can be env vars, flags, file, etcd, k8s configmap, etc.

• Mergeable Config - If you specify multiple sources of config, regardless of format, they will be merged and presented in a single view. This massively simplifies priority order loading and changes based on environment.

• Observe Changes - Optionally watch the config for changes to specific values. Hot reload your app using Go Config's watcher. You don't have to handle ad-hoc hup reloading or whatever else, just keep reading the config and watch for changes if you need to be notified.

• Sane Defaults - In case config loads badly or is completely wiped away for some unknown reason, you can specify fallback values when accessing any config values directly. This ensures you'll always be reading some sane default in the event of a problem.

Documentation

Overview

Package config is an interface for dynamic configuration.

Index

• Variables
• func Bytes() []byte
• func Get(path ...string) reader.Value
• func Load(source ...source.Source) error
• func LoadFile(path string) error
• func Map() map[string]interface{}
• func Scan(v interface{}) error
• func Sync() error
• type Config
  • func NewConfig(opts ...Option) (Config, error)
• type Option
  • func WithLoader(l loader.Loader) Option
  • func WithReader(r reader.Reader) Option
  • func WithSource(s source.Source) Option
  • func WithWatcherDisabled() Option
• type Options
• type Watcher
  • func Watch(path ...string) (Watcher, error)

Variables

var (
	// Default Config Manager.
	DefaultConfig, _ = NewConfig()
)

Functions

func Bytes

func Bytes() []byte

Return config as raw json.

func Get

func Get(path ...string) reader.Value

Get a value from the config.

func Load

func Load(source ...source.Source) error

Load config sources.

func LoadFile

func LoadFile(path string) error

LoadFile is short hand for creating a file source and loading it.

func Map

func Map() map[string]interface{}

Return config as a map.

func Scan

func Scan(v interface{}) error

Scan values to a go type.

func Sync

func Sync() error

Force a source changeset sync.

Types

type Config

type Config interface {
	// provide the reader.Values interface
	reader.Values
	// Init the config
	Init(opts ...Option) error
	// Options in the config
	Options() Options
	// Stop the config loader/watcher
	Close() error
	// Load config sources
	Load(source ...source.Source) error
	// Force a source changeset sync
	Sync() error
	// Watch a value for changes
	Watch(path ...string) (Watcher, error)
}

Config is an interface abstraction for dynamic configuration.

func NewConfig

func NewConfig(opts ...Option) (Config, error)

NewConfig returns new config.

type Option

type Option func(o *Options)

func WithLoader

func WithLoader(l loader.Loader) Option

WithLoader sets the loader for manager config.

func WithReader

func WithReader(r reader.Reader) Option

WithReader sets the config reader.

func WithSource

func WithSource(s source.Source) Option

WithSource appends a source to list of sources.

func WithWatcherDisabled

func WithWatcherDisabled() Option

type Options

type Options struct {
	Loader loader.Loader
	Reader reader.Reader

	// for alternative data
	Context context.Context

	Source []source.Source

	WithWatcherDisabled bool
}

type Watcher

type Watcher interface {
	Next() (reader.Value, error)
	Stop() error
}

Watcher is the config watcher.

func Watch

func Watch(path ...string) (Watcher, error)

Watch a value for changes.