Amazon EC2 Fleet added support for Block Device Mapping overrides

Starting today, EC2 Fleet customers can override the Block Device Mapping specified in the Launch Template when launching a new fleet. With this release, customers save the effort of creating and associating new Launch Templates with their fleet requests, when they need to customize the Block Device Mapping but keep rest of the instance configurations the same. Customers use EC2 Fleet to access wider EC2 capacity across instance types and availability zones within a single launch request. To provide their EC2 instance configurations such as Amazon Machine Images, Key pair etc, customers associate a Launch Template with their Fleet requests. They can override the values specified for select parameters in the Launch Template for each instance type. With this release, customers can also override Block Device Mapping parameters specified in the Launch Template. With Block Device Mapping, customers can launch additional EBS volumes or instance store volumes to attach to an instance, or update the Block Device Mapping specified in the Amazon Machine Image that you use to launch the instances. The feature is available in all commercial AWS regions and the AWS GovCloud (US) Regions. To learn more, refer the [API references](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API%5FFleetLaunchTemplateOverrides.html) and [EC2 user guide](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/create-ec2-fleet.html).