Sample config file:
# A comment
filesize = 10MB
log_level = Debug
log_file = /var/log/my.log
Quotes are not trimmed. Whitespaces before and after the value are trimmed.
Unmarshal config into struct
type Settings struct {
//ServerPort config value; if key not found in config the default 8080 is used
ServerPort int `cfg:"server_port" default:"8080"`
//Filesize returns bytes of specified filesize
Filesize cfg.Filesize `cfg:"filesize"`
//Log the nested struct
Log
}
type Log struct {
//File config key without default value; if not found an error is returned
File string `cfg:"log_file"`
//Level type LogLevel unmarshals the value "info" or "debug" into type LogLevel
Level LogLevel `cfg:"log_level"`
}
// LogLevel custom int type which holds the log level
type LogLevel int
//Possible log levels
const (
//Info logs everything with severity "Info"
Info = iota
//Debug logs everything with severity "Debug"
Debug
)
// Unmarshal the custom unmarshaler for the log level
func (lm *LogLevel) Unmarshal(value string) error {
if strings.ToLower(value) == "info" {
*lm = LogLevel(Info)
return nil
} else if strings.ToLower(value) == "debug" {
*lm = LogLevel(Debug)
return nil
}
return fmt.Errorf("unexpected config value '%s' for log level", value)
}
func main() {
// create a new ConfigFiles structure
c := cfg.ConfigFiles{}
// search for a config 'myconfig.conf' in folder '/etc' it fails if file is not found.
c.AddConfig("/etc", myconfig.conf, true)
settings := new(Settings)
// merges the config values into the settings struct
def, err := c.MergeConfigsInto(settings)
if err != nil {
panic(err)
}
for k, v := range def { // applied defaults
fmt.Printf("using default value %s for key %s\n", v.Value, k)
}
fmt.Println(settings.ServerPort)
fmt.Println(settings.Filesize)
fmt.Println(settings.Log.File)
fmt.Println(settings.Log.Level)
}