ToLogFile returns an io.Writer to configure WithOutput() option to write to a file and manage log rotation using lumberjack.

ToNull returns an io.Writer to configure WithOutput() option to discard all output.

ToStdOut returns an io.Writer to configure WithOutput() option to write to standard out.

WithLevel configures the log level.

WithNullLogger sets the logger to discard all output.

WithOutput configures the output destination.

logger instance used by the application.

logrus hook to write log to file.

type of log format.

Options is a function type that can be used to configure the logger.