I have a databricks job on E2 architecture in which I want to retrieve the workspace instance name within a notebook running in a Job cluster context so that I can use it further in my use case. 

While the call

dbutils.notebook.entry_point.getDbutils().notebook().getContext().tags().apply("browserHostName") 

works in an All-Purpose cluster in an interactive way, this key does not exist when running in a Job cluster context.