// Caller must have lock.
func (wp *Pool) updateWorker(inst cloud.Instance, it arvados.InstanceType) (*worker, bool) {
secret := inst.Tags()[wp.tagKeyPrefix+tagKeyInstanceSecret]
// Caller must have lock.
func (wp *Pool) updateWorker(inst cloud.Instance, it arvados.InstanceType) (*worker, bool) {
secret := inst.Tags()[wp.tagKeyPrefix+tagKeyInstanceSecret]