[Enhancement]: Manage OpenSearch index auto creation cluster setting in Terraform provider

[janfreymann]

Description

Cluster-specific settings like index auto creation can be configured via the OpenSearch API.

We could not find a way to manage the index auto creation setting in Terraform. That is why we use curl to change the setting outside of the terraform-managed data:

curl -X PUT "https://cluster-domain.example.com/_cluster/settings?pretty" -H 'Content-Type: application/json' -d'
{
  "persistent": {
    "action.auto_create_index": "false"
  }
}'

It would be great if the index auto creation setting (as well as other cluster settings?) could be managed with Terraform.

Affected Resource(s) and/or Data Source(s)

• aws_opensearch_domain
• aws_opensearch_domain -> cluster_config

Potential Terraform Configuration

resource "aws_opensearch_domain" "os-cluster" {
  cluster_config {
    settings {
      action_auto_create_index = false
    } 
  }
}

References

• https://opensearch.org/docs/latest/api-reference/cluster-api/cluster-settings/

Would you like to implement a fix?

None

[github-actions]

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[DrFaust92]

I think you are looking for this as this is a opensearch specific config that is managed via the opensearch API:

https://registry.terraform.io/providers/opensearch-project/opensearch/latest/docs/resources/cluster_settings - this support what you are requesting

[justinretzolk]

Similar #27371

Based on the most recent comment in the linked issue, it seems a though this currently isn't supported via the available API(s). Since this isn't exactly the same as the other issue, I'm going to leave this open for now, so that we can track it separately. Thank you very much for taking the time to raise this!

[janfreymann]

https://registry.terraform.io/providers/opensearch-project/opensearch/latest/docs/resources/cluster_settings - this support what you are requesting

Thanks for the hint! We're currently using this HashiCorp AWS provider in production. To switch providers, we would need to migrate everything to the OpenSearch Project provider. Due to the effort and risk involved, we've decided not to make the switch (for now).