kubernetes/cmd/kubeadm/app/phases/certs/renewal/expiration.go

type ExpirationInfo …

// newExpirationInfo returns a new ExpirationInfo
func newExpirationInfo(name string, cert *x509.Certificate, externallyManaged bool) *ExpirationInfo { … }

// ResidualTime returns the time missing to expiration
func (e *ExpirationInfo) ResidualTime() time.Duration { … }