Amazon OpenSearch Service domain is not publicly accessible

# Restrict OpenSearch access policy to your account only
resource "aws_opensearch_domain" "<example_resource_name>" {
  domain_name = "<example_resource_name>"

  # critical: limits access to the owning account, removing public access
  access_policies = jsonencode({
    Version = "2012-10-17"
    Statement = [{
      Effect    = "Allow"
      Principal = { AWS = "arn:aws:iam::<ACCOUNT_ID>:root" }
      Action    = "es:*"
      Resource  = "arn:aws:es:<REGION>:<ACCOUNT_ID>:domain/<example_resource_name>/*"
    }]
  })
}

# CloudFormation: restrict OpenSearch access policy to your account only
Resources:
  <example_resource_name>:
    Type: AWS::OpenSearchService::Domain
    Properties:
      DomainName: <example_resource_name>
      AccessPolicies:  # critical: restricts access to your account only, removing public access
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              AWS: arn:aws:iam::<ACCOUNT_ID>:root  # critical: only this account can access
            Action: es:*
            Resource: arn:aws:es:<REGION>:<ACCOUNT_ID>:domain/<example_resource_name>/*

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {"AWS": "arn:aws:iam::<ACCOUNT_ID>:root"},
      "Action": "es:*",
      "Resource": "arn:aws:es:<REGION>:<ACCOUNT_ID>:domain/<DOMAIN_NAME>/*"
    }
  ]
}