Get rid of aws-codedeploy-api and asCodeDeployLoadBalancer

[eladb]

I don't see a problem for the aws-codedeploy module to take a dependency on aws-elbv2 and aws-elb, eliminating the need for this intricate type hierarchy.

[skinny85]

A little bit of an explanation why it was modeled this way.

We wanted to pass either a Classic ELB, or an ALB/NLB Target Group directly to the loadBalancer property of a CodeDeploy Deployment Group when creating it:

new codedeploy.DeploymentGroup(this, 'DG', {
  // ...
  loadBalancer: new elasticloadbalancing.LoadBalancer(this, 'ELB', {
    // ...
  }),
});

Because CodeDeploy depends on aws-autoscaling (for AutoScalingGroup), it has a transitive dependency on both aws-elasticloadbalancing and aws-elasticloadbalancingv2, and so none of those packages could have a type from aws-codedeploy that could be implemented by both elasticloadbalancing.LoadBalancer and elasticloadbalancingv2.TargetGroup (as that would be a cycle).

If you want to get rid of this dependency, we need to change the current API of DeploymentGroup.

[eladb]

Yes, let's change the API.

Would it make sense to use "union-like classes":

loadBalancer: codedeploy.LoadBalancer.classic(elb)
// or
loadBalancer: codedeploy.LoadBalancer.targetGroup(group)

[skinny85]

Yeah, that's probably the only sensible way to go here.