Field Level Security in Elasticsearch

Introduction

Field Level Security (FLS) in Elasticsearch allows you to control access to individual fields within your documents. This is particularly useful when you need to restrict sensitive information from certain users while still allowing them to access other parts of the document. In this tutorial, we will cover the basics of setting up and using FLS in Elasticsearch.

Prerequisites

Before we dive into Field Level Security, ensure that you have the following:

• Elasticsearch instance running with X-Pack installed.
• Basic understanding of Elasticsearch security concepts.
• Administrative access to your Elasticsearch cluster.

Setting Up Field Level Security

To set up Field Level Security, you need to define roles that specify which fields can be accessed by users assigned to those roles.

Defining Roles

Let's start by defining a role that includes permissions for accessing specific fields. In this example, we will create a role named read_sensitive_fields that grants read access to the username and email fields of a document.

PUT /_security/role/read_sensitive_fields
{
  "indices": [
    {
      "names": [ "my_index" ],
      "privileges": [ "read" ],
      "field_security": {
        "grant": [ "username", "email" ]
      }
    }
  ]
}
                

Assigning Roles to Users

After defining the role, you need to assign it to users who should have access to the specified fields. Below is an example of assigning the read_sensitive_fields role to a user named john_doe.

PUT /_security/user/john_doe
{
  "password" : "password123",
  "roles" : [ "read_sensitive_fields" ],
  "full_name" : "John Doe",
  "email" : "john.doe@example.com"
}
                

Testing Field Level Security

To test the Field Level Security, you can execute a search query as the user john_doe and verify that only the granted fields are returned. Below is an example search query.

GET /my_index/_search
{
  "query": {
    "match_all": {}
  }
}
                

If the setup is correct, the response will only include the username and email fields.

Conclusion

In this tutorial, we explored how to set up and use Field Level Security in Elasticsearch. By defining roles with specific field permissions and assigning them to users, you can ensure that sensitive information is only accessible to authorized users.

Field Level Security is a powerful feature that enhances the security of your Elasticsearch data. Use it wisely to protect your sensitive information.