Installation
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go get github.com/spf13/viper
Write Config Files
app.env
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DB_DRIVER="postgres"
DB_SOURCE="postgres://root:secret@localhost:5432/test_db?sslmode=disable"
SERVER_ADDRESS="0.0.0.0:3000"
you can also create config files in other extensions like yaml, json, TOML …
Read Config Files
env/config.go
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package env
import "github.com/spf13/viper"
type Config struct {
DBDriver string `mapstructure:"DB_DRIVER"`
DBSource string `mapstructure:"DB_SOURCE"`
ServerAddress string `mapstructure:"SERVER_ADDRESS"`
}
func LoadConfig(path string) (config Config, err error) {
viper.AddConfigPath(path)
viper.SetConfigName("app") // your config file's name : [app].env
viper.SetConfigType("env") // your config file's extension : app.[env]
viper.AutomaticEnv()
err = viper.ReadInConfig()
if err != nil {
return
}
err = viper.Unmarshal(&config)
return
}
main.go
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package main
import (
"testenv/env"
"fmt"
"reflect"
)
func main() {
config, err := env.LoadConfig(".") // path of app.env
if err != nil {
log.Fatal("cannot read config: ", err)
}
values := reflect.ValueOf(config)
typeOfFields := values.Type()
for i := 0; i < values.NumField(); i++ {
fmt.Printf(" %s : %v \n", typeOfFields.Field(i).Name, v.Field(i).Interface())
}
}
Output
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DBDriver : postgres
DBSource : postgres://root:secret@localhost:5432/test_db?sslmode=disable
ServerAddress : 0.0.0.0:3000