kubernetes/cmd/kubeadm/app/phases/bootstraptoken/node/token.go

// CreateNewTokens tries to create a token and fails if one with the same ID already exists
func CreateNewTokens(client clientset.Interface, tokens []bootstraptokenv1.BootstrapToken) error { … }

// UpdateOrCreateTokens attempts to update a token with the given ID, or create if it does not already exist.
func UpdateOrCreateTokens(client clientset.Interface, failIfExists bool, tokens []bootstraptokenv1.BootstrapToken) error { … }