AWS ElasticSearch cluster is not in a VPC

Description

AWS Elasticsearch domains that reside within a VPC have an extra layer of security when compared to ES domains that use public endpoints. Launching an Amazon ES cluster within an AWS VPC enables secure communication between the ES cluster (domain) and other AWS services without the need for an Internet Gateway, a NAT device or a VPN connection and all traffic remains secure within the AWS Cloud.

Fix - Buildtime

Terraform

• Resource: aws_elasticsearch_domain
• Argument: vpc_options

resource "aws_elasticsearch_domain" "es" {
          domain_name           = var.domain
          elasticsearch_version = "6.3"
        
          cluster_config {
            instance_type = "m4.large.elasticsearch"
          }
        
+         vpc_options {
+           subnet_ids = [
+             data.aws_subnet_ids.selected.ids[0],
+             data.aws_subnet_ids.selected.ids[1],
+           ]
        
            security_group_ids = [aws_security_group.es.id]
          }
        
        }