Access control#

Aiven for OpenSearch® supports index-level access control lists (ACL) to control permissions. This approach allows you to limit the operations that are available to specific service users and restrict access to certain data sets.


When access control is initially enabled for the service, a set of rules that allows full unlimited access to existing service users is created automatically.

Patterns and permissions#

Rules are defined separately for each user as pattern/permission combinations. The pattern defines the indices that the permission applies to. Patterns are glob-style, where * matches any number of characters (including none) and ? matches any single character.

You can grant the following permissions. They are ordered by importance:

  1. deny: explicitly deny access

  2. admin: unlimited access to the index

  3. readwrite: full access to documents

  4. read: allow only searching and retrieving documents

  5. write: allow updating, adding, and deleting documents

The permission also implies which index APIs the service user can access:

  1. deny: no access

  2. admin: no restrictions

  3. readwrite: _search, _mget, _bulk, _mapping, _update_by_query, _delete_by_query

  4. read: _search, _mget

  5. write: _bulk, _mapping, _update_by_query, _delete_by_query


When no rules match, access is implicitly denied.


write permission allows creating indices that match the rule’s index pattern but does now allow deleting them. Indices can only be deleted when a matching admin permission rule exists.

When multiple rules match, they are applied in the order listed above regardless of the rule order (see the example below).


As an example, we can use the following set of rules:

  • logs_*/read

  • events_*/write

  • logs_2018*/deny

  • logs_201901*/read

  • logs_2019*/admin

This set would allow the service user to

  • add documents to events_2018 (second rule),

  • retrieve and search documents from logs_20171230 (first rule),

  • gain full access to logs_20190201 (fifth rule), and

  • gain full access to logs_20190115 (fifth rule, as the admin permission gets higher priority than the read permission in the fourth rule.

The same set would deny the service user to

  • gain any access to messages_2019 (no matching rules),

  • read or search documents from events_2018 (the second rule only grants write permission), and

  • write to or use the API for logs_20171230 (the first rule only grants read permission).

Access control and aliases#


Aliases are not expanded. If you use aliases, the ACL must include a rule where the pattern matches the alias.


Rules matching the indices the alias “expands” to are not used, only the rule where the pattern matches the alias itself.

Controlling access to top-level APIs#

In addition to indices, ACLs can be used to control access to “top-level” APIs by creating a API specific rule.


Access to the _cluster, _cat, _tasks, _scripts, _snapshot, and _nodes APIs is controlled by the service itself, not by these ACLs.


Access to the top-level _mget, _msearch, and _bulk APIs can also be controlled by enabling ExtendedACL.

Using ACLs to control access#

Only rules where the pattern starts with _ are considered for top-level API access. Normal index rules do not grant access to these APIs. For example, *search/admin only grants access to indices that match the pattern, not to _msearch.


  • _*/admin would grant unlimited access to all top-level APIs

  • _msearch/admin grants unlimited access to the _msearch API only

The ACL only controls access to the API and not what it can be used for. Giving access to the top-level API will in effect circumvent index specific rules, for example _msearch/admin access allows searching any index via the API as the indices to search are defined in the request body itself.


When top-level API access is granted via explicit ACL the request content is not examined.

Enabling extended ACLs#

Instead of creating a rule that allows access to the top-level _mget, _msearch and _bulk APIs, you can switch on the ExtendedAcl. This will automatically enable these APIs for the user and each API request is checked to make sure operations only target indices that the user has appropriate permissions for (as defined by the normal index ACLs).

As the service must inspect the content of the request, this can cause performance and latency issues. The requests are also limited to a maximum of 15000 bytes in size. If the request is too large or if any of the operations or indices are not allowed by the ACLs, the entire request is rejected.


ACLs permitting access to top-level API will always take precedence over ExtendedACL, you can for example allow access to _bulk for a trusted service account to do mass updates.

Access control and OpenSearch Dashboards#

Enabling ACLs does not restrict access to OpenSearch Dashboards itself, but all requests done by OpenSearch Dashboards are checked against the current user’s ACLs.


You might encounter HTTP 500 internal server errors when you try to view dashboards as a service user that has read-only access to certain indices, as these dashboards call the _msearch API. In such cases, add a new ACL rule that grants Admin access to _msearch for that service user.