Get AZ inside Lambda


Has anyone found a way of determining which AZ the current Lambda function is operating in?

I need to work with DB connections to outside the VPC where Lambda is running. The DB is set up with High Availability, with two access points, each in an AZ. Would like the function in an AZ to speak to the DB in the same AZ. So if my Lambda function is running in HA in eu-west-1a, to call the DB endpoint also in eu-west-1a.