Elasticsearch & Full Text Search Systems · Lesson

Field and Document Level Security

Implement fine-grained security by restricting access to specific fields or even individual documents based on user roles.

Field and Document Level Security is a free Elasticsearch & Full Text Search Systems lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Elasticsearch & Full Text Search Systems learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

Why Fine-Grained Security?

In Elasticsearch, you might not want every user to see all data. Sometimes, certain users should only access specific parts of documents or only a subset of documents.

This is where fine-grained security comes in. It allows you to control access at a much more detailed level than just index permissions.

What is Field Level Security (FLS)?

Field Level Security (FLS) lets you restrict which fields within a document a user can see. Imagine a product document with many fields.

A sales agent might only need to see product_name and price.
An inventory manager might need quantity and supplier_id.

FLS ensures users only retrieve the fields relevant to their role, hiding sensitive or irrelevant data.

Configuring FLS in Roles

FLS is configured within a user's role definition. You specify which fields are granted (allowed) or excepted (disallowed) for specific indices.

Using grant is generally safer as it follows a whitelist approach, only allowing explicitly listed fields.

{
  "applications": [],
  "cluster": [],
  "indices": [
    {
      "names": ["products"],
      "privileges": ["read"],
      "field_security": {
        "grant": ["product_name", "price"]
      }
    }
  ],
  "run_as": [],
  "metadata": {},
  "transient_metadata": {}
}

FLS Example: Product Viewer Role

Let's create a role named product_viewer. Users with this role can read documents from the products index, but only see the product_name and price fields.

Other fields like internal_cost or supplier_secret would be hidden.

PUT /_security/role/product_viewer
{
  "indices": [
    {
      "names": ["products"],
      "privileges": ["read"],
      "field_security": {
        "grant": ["product_name", "price"]
      }
    }
  ]
}

What is Document Level Security (DLS)?

Document Level Security (DLS) allows you to restrict which documents a user can see. Instead of hiding fields, DLS filters entire documents based on a query.

For example, a regional sales manager should only see sales orders from their specific region, not from other regions.

Configuring DLS in Roles

DLS is configured in a role using a query object. This query acts as a filter that is automatically applied to all search requests made by users assigned to that role.

Only documents matching this query will be returned to the user, regardless of their original search request.

{
  "applications": [],
  "cluster": [],
  "indices": [
    {
      "names": ["sales_data"],
      "privileges": ["read"],
      "query": {
        "term": { "region.keyword": "east" }
      }
    }
  ],
  "run_as": [],
  "metadata": {},
  "transient_metadata": {}
}

DLS Example: East Region Sales

Let's create a role named east_sales_manager. Users with this role can read documents from the sales_data index, but only those documents where the region field is east.

This effectively isolates sales data by region.

PUT /_security/role/east_sales_manager
{
  "indices": [
    {
      "names": ["sales_data"],
      "privileges": ["read"],
      "query": {
        "term": { "region.keyword": "east" }
      }
    }
  ]
}

Combining FLS and DLS

You can apply both Field Level Security and Document Level Security within a single role definition.

This means a user could be restricted to seeing only specific fields, AND only specific documents that match a filter query. This offers a very powerful way to create fine-grained access control.

Best Practices for FLS/DLS

When implementing FLS and DLS:

Design roles carefully: Plan out exactly what each user group needs to see.
Test thoroughly: Always verify that your roles provide the intended level of access, and nothing more.
Use `grant` for FLS: Whitelisting fields is generally more secure than blacklisting.
Keep DLS queries simple: Complex queries can impact performance.
Least privilege: Always grant the minimum necessary permissions.

Quick Check: Security Features

Which of the following statements about Elasticsearch Field and Document Level Security are true?

Recap: Fine-Grained Security

You've learned about Field Level Security (FLS) for restricting visible fields and Document Level Security (DLS) for filtering documents based on queries.

These powerful features, configured within user roles, enable you to create highly granular access control, ensuring users only see the data they are authorized for. This is crucial for maintaining data privacy and security in your Elasticsearch cluster.

Frequently asked questions

Is the “Field and Document Level Security” lesson free?

Yes — the full text of “Field and Document Level Security” is free to read here on the web, and the Elasticsearch & Full Text Search Systems course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Elasticsearch & Full Text Search Systems course, upgrade to CoddyKit PRO.

What will I learn in “Field and Document Level Security”?

Implement fine-grained security by restricting access to specific fields or even individual documents based on user roles. You practise Elasticsearch & Full Text Search Systems with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start Elasticsearch & Full Text Search Systems?

No prior experience is required. Elasticsearch & Full Text Search Systems on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “Field and Document Level Security” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this Elasticsearch & Full Text Search Systems lesson?

Yes. Every Elasticsearch & Full Text Search Systems lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

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