GitHub - kkyr/fig: A minimalist Go configuration library (original) (raw)
fig
fig is a tiny library for loading an application's configuration into a Go struct.
Why fig?
- 🛠️ Define your configuration, validations and defaults all within a single struct.
- 🌍 Easily load your configuration from a file, the environment, or both.
- ⏰ Decode strings into
Time,Duration,Regexp, or any custom type that satisfies theStringUnmarshalerinterface. - 🗂️ Compatible with
yaml,json, andtomlfile formats. - 🧩 Only three external dependencies.
Getting Started
$ go get -d github.com/kkyr/fig
Define your config file:
config.yaml
build: "2020-01-09T12:30:00Z"
server: ports: - 8080 cleanup: 1h
logger: level: "warn" trace: true
Define your struct along with validations or defaults:
package main
import ( "fmt"
"github.com/kkyr/fig" )
type Config struct {
Build time.Time fig:"build" validate:"required"
Server struct {
Host string fig:"host" default:"127.0.0.1"
Ports []int fig:"ports" default:"[80,443]"
Cleanup time.Duration fig:"cleanup" default:"30m"
}
Logger struct {
Level string fig:"level" default:"info"
Pattern *regexp.Regexp fig:"pattern" default:".*"
Trace bool fig:"trace"
}
}
func main() { var cfg Config err := fig.Load(&cfg) // error handling omitted
fmt.Printf("%+v\n", cfg) // {Build:2019-12-25T00:00:00Z Server:{Host:127.0.0.1 Ports:[8080] Cleanup:1h0m0s} Logger:{Level:warn Pattern:.* Trace:true}} }
Fields marked as required are checked to ensure they're not empty, and default values are applied to fill in those that are empty.
Environment
By default, fig will only look for values in a config file. To also include values from the environment, use the UseEnv option:
fig.Load(&cfg, fig.UseEnv("APP_PREFIX"))
In case of conflicts, values from the environment take precedence.
Usage
See usage examples.
Documentation
For detailed documentation, visit go.dev.
Contributing
PRs are welcome! Please explain your motivation for the change in your PR and ensure your change is properly tested and documented.