DefaultCertificateMonitors returns 3 CertificateMonitors with the following periods: 1 day, 1 week and 4 weeks.

Create a new filesystem backend, all directories will be created for the given path Using a filesystem backend in production is not recommended!.

ErrAlreadyStarted is returned when start is called on an already running monitor.

ErrInvalidDuration is given when a period duration is 0 or negative.

ErrNotFound indicates that the specified crypto storage entry couldn't be found.

CertificateMonitor represents a go procedure which monitors expiring certificates within a given period.

Storage interface containing functions for storing and retrieving keys.