Get WorkerID from within a activity

So, this activity has to dynamically determine if that particular worker machine has enough resources (storage) to be able to continue the work. For that I am storing/ updating the storage information of each worker in a separate DB. This activity will query the DB and determine if that worker has enough unreserved storage left, then only it will continue, else reject. For this storing and querying purpose of each worker’s unreserved storage information I need to access the unique WorkerID for each worker machine.