GetBoolEnv parses a boolean environment variable by the given key, if env is empty, returns the given fallback value.

GetDurationEnv parses a duration environment variable by the given key, if env is empty, returns the given fallback value.

GetStringEnv returns an environment variable by the given key, if env is empty, returns the given fallback value.

RegisterInterruptHandler registers a handler of interrupt signals from the OS.

RegisterSignalHandler registers a handler of signals from the OS.