Debugf logs a debug level log message.

Errorf logs an error level log message.

Infof logs an info level log message.

Tracef logs a trace level log message.

Warnf logs a warn level log message.

Log can be assigned a proper logger, such as logrus configured to your liking.

StdLog is a simplistic logger for rig.

Logger interface should be implemented by the logging library you wish to use.