[BUG][opensearch] Can't define nodeGroup to be coordinating only

[brgsousa]

Describe the bug
Installing a helm chat opensearch version 2.17.0, I try to brake the cluster into different pieces: coordinating, clustermanager, hot data and warm data, similar to what is described in https://opensearch.org/docs/latest/tuning-your-cluster/ . But the coordinating nodegroup act as data node as well, when it shouldn't!

To Reproduce
Steps to reproduce the behavior:

1. Install four helm charts opensearch version 2.17.0. These are snippets of values.yaml below
   Clustermanager nodegroup:
   roles: ["master"]
   Coordinating nodegroup:
   roles: []
   Hot data nodegroup:
   roles: ["ingest" , "data"]
   Warm data nodegroup:
   roles: ["ingest" , "data"]

2. Create new index.

3. Index is created considering "Hot data nodegroup", "Warm data nodegroup" and "Coordinating nodegroup" as nodes to scatter shards.

Expected behavior
Coordinating nodegroup should behave as only coordinating, not as data as well.

Chart Name
opensearch version 2.17.0

Host/Environment (please complete the following information):

• Helm Version: 3.12.2-1
• Kubernetes Version: 1.26.6-00

[prudhvigodithi]

[Triage]
Hey @brgsousa there is issue related to this topic in core repo opensearch-project/OpenSearch#3412, the is fix in the main branch but not back ported yet, once backported and released (mostly for 3.0.0 OpenSearch release), using the [] should support in helm chart.
Thanks