config

README

go-config

Offers a rich configuration file handler.

• Read configuration files with ease
• Bind CLI flags
• Bind environment variables
• Watch file (or files) and get notified if they change

---

Uses the following precedence order:

• flag
• env
• toml

flag	env	toml	result
☑	☑	☑	flag
☑	☑	☐	flag
☑	☐	☑	flag
☐	☑	☑	env
☑	☐	☐	flag
☐	☑	☐	env
☐	☐	☑	toml

If flag is set and not given, it will parse env or toml according to their precedence order (otherwise flag default).

Basic Example

Call the Load() method to load a config.

    type MyConfig struct {
        Key1    string   `toml:"key1"`
        Key2    string   `toml:"key2"`
        Port    int      `toml:"-" flag:"port"`
        Secret  string   `toml:"-" flag:"-" env:"secret"`
    }

    _ = flag.Int("port", 8080, "Port to listen on") // <- notice no variable
    flag.Parse()

    var cfg MyConfig
    err := config.Load("./config.toml", &cfg)

    fmt.Printf("Loaded config: %#v\n", cfg)
    // Port info is in cfg.Port, parsed from `-port` param
    // Secret info is in cfg.Secret, parsed from `secret` environment variable

File Watching

Call Watch() method, get a notification channel and listen...

    ch, err := config.Watch(context.Background(), "config.toml")

    for {
        select {
        case e := <-ch:
        	if e != nil {
        		fmt.Printf("Error occured watching file: %v", e)
        		continue
        	}

            fmt.Println("Changed, reloading...")
            var cfg MyConfig
            err := config.Load("config.toml", &cfg)
            fmt.Printf("Loaded: %v %#v\n", err, cfg)
            // Handle cfg...
        }
    }

Documentation

Overview

Package config offers a rich configuration file handler.

Index

• func Load(filepath string, dst interface{}) error
• func Watch(ctx context.Context, pathtofile string) (<-chan error, error)

Functions

func Load

func Load(filepath string, dst interface{}) error

Load loads filepath into dst. It also handles "flag" binding.

func Watch

func Watch(ctx context.Context, pathtofile string) (<-chan error, error)

Watch starts watching the given file for changes, and returns a channel to get notified on. Errors are also passed through this channel: Receiving a nil from the channel indicates the file is updated.