vs-deploy | Visual Studio Code extension that provides commands

It turns out that a lot more is involved in immutable deployments than in environment creation. Here is part of the response I received from AWS support, explaining the differences more clearly than I ever could:

What will happen on environment creation

1) The new environment creation command is issued

2) A CloudFormation stack is created to launch the resources associated with the environment

3) The instance or instances that will be launched as part of the AutoScaling group are provisioned: this implies to execute, in that particular case, CMD-StartUp which will execute also all the hooks associated. At this time the environment is provisioned.

What will happen on Immutable Deployments

1) A new CloudFormation stack is created to so the current one is not getting modified

2) One instance is being launched in a temporary AutoScaling group

3) The instance is provisioned the same way as the existing one was at environment creation with CMD-StartUp

4) The instance, once ready, is added to the environment's load balancer

5) The instance has to pass all health checks. If the environment is of type "Web server", it needs to pass 12 consecutive health checks; if the environment is of type "worker", it needs to pass 18 health checks. Since Enhanced health check is reporting the status every 10 seconds, it means that in the best possible scenario, this is going to take 2 minutes (10 x 12 = 120). (More information regarding this [1])

6) The "CMD-ImmutableDeploymentFlip" command needs to be executed on the new instance/instances, which will then call the "infra-reregister-cfn-hup.rb" script and performs different actions

7) Post-deployment configuration starts

8) When deployment succeeded, the old instance(s) needs to be terminated

9) The deployment is completed.

Take a look at the mappings section of the wiki to remap source directories to output directories. In your case, you need to add this to your targets: