Is OpenSearch per index access control possible?

Yes, per-index access control is possible in Amazon OpenSearch Service. This can be achieved using fine-grained access control, which allows you to set specific permissions for different users at various levels, including the index level.

With fine-grained access control, you can create roles that have permissions for specific indices. Then, you can map these roles to individual users. This way, you can ensure that each user only has access to their designated index.

For example, if you have two indices (let's call them index1 and index2) and two users (user1 and user2), you could set up the access control as follows:

1. Create a role (e.g., "index1_access") with permissions to access and perform operations on index1.
2. Create another role (e.g., "index2_access") with permissions to access and perform operations on index2.
3. Map user1 to the "index1_access" role.
4. Map user2 to the "index2_access" role.

This configuration would ensure that user1 can only access index1, and user2 can only access index2.

Fine-grained access control in OpenSearch Service provides this level of granularity, allowing you to control access not just at the index level, but also at the cluster, document, and even field levels if needed. This feature gives you the flexibility to implement precise access controls that match your security requirements.
Sources
Fine-grained access control in Amazon OpenSearch Service - Amazon OpenSearch Service
Configuring OpenSearch permissions with fine-grained access control - Amazon Bedrock