FilterLevels returns all the logrus.Level values <= maxLevel.

FormatForSyslog formats logs in a way tailored for syslog.

safeParseLogLevel parses a string version of a logrus log level, defaulting to logrus.PanicLevel on failure.

FieldForceFlush is a field name used to signal to the BackgroundHook that it should flush the log after this message.

BackgroundHook is a logrus Hook that (synchronously) formats each log and sends it to one or more Destinations for writing ona background thread.

Formatter is our custom log formatter designed to balance ease of machine processing with human readability.

NullWriter is a dummy writer that always succeeds and does nothing.