If rally server is terminated, new servers created by auto scaling does not join cluster

Environment:
AWS CLI version: aws-cli/1.16.134 Python/2.7.6 Linux/3.13.0-141-generic botocore/1.12.124
Checked out repo: github.com/couchbase-partners/amazon-cloud-formation-couchbase.git
Branch: allAreRallys/testing
Last commit: cd0d376a34a5c8bb279b03b6b4e74fa0fb5f96c7
Working in dir: amazon-cloud-formation-couchbase/generator

Steps to reproduce:

• Create cloud template using yaml file provided below.
• Terminate rally server
• Check if new instance with data service gets created and joined cluster

Observed that new data node created, but new node does not have tag "cb:cluster-member" and it does not get added to cluster and rebalanced in automatically.

Expected o/p: new node should get created, added to cluster and rebalanced in.

Note: If any other server than rally server is terminated, new server gets added to cluster and rebalanced in.

File used to create cloud template-

serverVersion: 6.0.1

syncGatewayVersion: 2.1.0

cluster:

 - group: group1

 license: BYOL

 nodeCount: 3

 nodeType: m4.4xlarge

 dataDiskSize: 100

 services:

 - data

 - group: group2

 license: BYOL

 nodeCount: 0

 nodeType: m4.4xlarge

 dataDiskSize: 100

 services:

 - query

 - index

 - fts

 - group: group3

 license: BYOL

 nodeCount: 0

 nodeType: m4.4xlarge

 dataDiskSize: 100

 services:

 - analytics

 - eventing