Different versions of application in same environment after update

[Epimetheus89]

We are using eb_deployer with blue-green deployment and the following settings:

environments:
  prod:
    inactive_settings:
      - namespace: aws:autoscaling:asg
        option_name: "MinSize"
        value: "1"
      - namespace: aws:autoscaling:asg
        option_name: "MaxSize"
        value: "1"

and having MinSize and MaxSize equal 2 in active_settings as default.

Now if we simply deploy a new version via eb_deploy -e prod, the environment is updated as follows:

1. inactive environment is scaled up from 1 to 2 instances (seeing one instance added in elastic beanstalk log)
2. new code version is deployed

Ending up in this state:

• Old instance: new code version
• New instance: old code version

So it seems that the newly added instance does not get the update of the new code.

Is this a bug in eb_deployer or in aws api? Can someone reproduce it?

Some more information:

• Enhanced Elastic Beanstalk health states that both instances have the same version, so you have to look at the machines to verify versions.
• AWS support asked if there is an application version specified while deploying the new configuration (upscaling)