How does Viper parse underlined configuration items?

[yzhengwei]

I used Viper to parse YAML to struct, but I found that I couldn't parse it when the struct key was different with the key in the YAML.Here is my struct and the yaml:

level: info
log_path: "/data/logs"
group: "sre"
max_size: 50
max_backups: 10
max_age: 7
compress: true
stdout: true

type Config struct {
	Level      string `yaml:"level"`
	LogPath    string `yaml:"log_path"`
	Stdout     bool   `yaml:"stdout"`
	App        string `yaml:"app"`
	Group      string `yaml:"group"`
	MaxSize    int    `yaml:"max_size"`
	MaxBackups int    `yaml:"max_backups"`
	MaxAge     int    `yaml:"max_age"`
	Compress   bool   `yaml:"compress"`
}

var config *Config

func main(){
	viper.SetConfigFile("config.yaml")

	viper.ReadInConfig()

	viper.Unmarshal(&config)

	fmt.Println(config)

}

output:
&{info  true  sre 0 0 0 true}

When the struct key has a different key name than a key in YAML, it cannot resolve it, like "max_size", How do I use viper parse it like I parse a YAML file?

[sagikazarmark]

https://github.com/spf13/viper/blob/master/TROUBLESHOOTING.md#unmarshaling-doesnt-work