Event-Based Mirroring: Listen for EC2 Service Events

[chelma]

Description

Per design discussion in (#35), we want to begin listening for and responding to AWS Service-emitted EventBridge Events to more swiftly capture new user traffic. This task is to listen for EC2 instances starting up/spinning down and automatically create mirroring configuration for them without having to take manual action or wait for a scheduled scan. It builds on the work accomplished in a preceding task (see #37).

This task will likely entail:

• Create new Rules to listen for both EC2 and EC2 Autoscaling Instance start/stop events on the AWS Account/Region's default Bus and kick off the appropriate per-ENI create/destroy Lambda to action it.
• Update the demo traffic source stacks to include an EC2 Autoscaling Group that can be used to test this behavior

Acceptance Criteria

• Demonstrate that mirroring configuration is correctly created/destroyed when EC2 Instances are added/removed from the User VPC WITHOUT having to wait for a scheduled scan.

[chelma]

It turns out that both ECS-on-EC2 and EC2 will use the same AWS Resources, code, and configuration. Therefore, this is effectively a duplicate of #37, with the exception of adding an dedicated, non-ECS autoscaling group to our demo test stack.

[chelma]

Mirroring is in place for EC2 instances. Since we can test the behavior using our ECS Cluster's backing ASG, I think I'm going to move the remaining work into a new issue and resolve this one.

[chelma]

Follow-up created; resolving this task.

#46