+func (cfg *Config) Start(reg *prometheus.Registry) error {
+ if cfg.Debug {
+ log.Level = logrus.DebugLevel
+ cfg.debugLogf = log.Printf
+ cfg.debugLogf("debugging enabled")
+ } else {
+ log.Level = logrus.InfoLevel
+ cfg.debugLogf = func(string, ...interface{}) {}
+ }
+
+ f := formatter[strings.ToLower(cfg.LogFormat)]
+ if f == nil {
+ return fmt.Errorf(`unsupported log format %q (try "text" or "json")`, cfg.LogFormat)
+ }
+ log.Formatter = f
+