Authentication basics in Elasticsearch - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Elasticsearch authentication request?

Given the following Elasticsearch request using basic authentication, what will be the HTTP status code in the response if the credentials are correct?

Elasticsearch

GET /_security/_authenticate

A 403

B 401

C 200

D 500

💡 Hint

Successful authentication returns HTTP 200 OK.

When the username and password are correct, Elasticsearch returns HTTP status 200 indicating successful authentication.

❓ Predict Output

intermediate

What error does this Elasticsearch request raise with missing authentication header?

What error will Elasticsearch return if you send a request to a secured cluster without any authentication header?

Elasticsearch

GET /_cluster/health

A 401 Unauthorized

B 200 OK

C 403 Forbidden

D 404 Not Found

💡 Hint

Missing authentication usually results in 401 Unauthorized.

Elasticsearch secured clusters require authentication. Without credentials, it returns 401 Unauthorized.

🧠 Conceptual

advanced

Which authentication method is supported natively by Elasticsearch for REST API?

Elasticsearch supports several authentication methods. Which one is supported natively for REST API calls without plugins?

A Basic Authentication with username and password

B OAuth 2.0 Bearer Tokens

C SAML Single Sign-On

D API Key with JWT signature

💡 Hint

Elasticsearch supports basic authentication out of the box.

Elasticsearch natively supports Basic Authentication using username and password for REST API calls. Other methods require plugins or external systems.

❓ Predict Output

advanced

What is the output of this API key authentication request?

Given this curl command using an API key for authentication, what will be the HTTP status code if the API key is invalid?

Elasticsearch

curl -H 'Authorization: ApiKey invalid_api_key' -X GET 'https://localhost:9200/_security/_authenticate'

A 400 Bad Request

B 200 OK

C 403 Forbidden

D 401 Unauthorized

💡 Hint

Invalid API keys cause 401 Unauthorized errors.

If the API key is invalid, Elasticsearch returns 401 Unauthorized indicating authentication failure.

🚀 Application

expert

How many roles are assigned to the user after this authentication response?

Given this Elasticsearch authentication response JSON, how many roles does the authenticated user have?

Elasticsearch

{
  "username": "admin",
  "roles": ["superuser", "monitoring_user", "kibana_user"],
  "full_name": "Admin User",
  "email": "[e-mail]",
  "metadata": {},
  "enabled": true
}

A 4

B 3

C 1

D 0

💡 Hint

Count the items in the roles array.

The roles array contains three strings, so the user has 3 roles assigned.

Practice

1. What is the main purpose of authentication in Elasticsearch?

easy

A. To backup the Elasticsearch index

B. To store data securely in the cluster

C. To verify the identity of a user or system before granting access

D. To improve search speed

Solution

1. Step 1: Understand authentication concept

   Authentication is the process of checking who you are before allowing access.

2. Step 2: Match with Elasticsearch context

   Elasticsearch uses authentication to verify user or system identity before access.

3. Final Answer:

   To verify the identity of a user or system before granting access -> Option C

4. Quick Check:

   Authentication = Verify identity [OK]

Hint: Authentication means checking who you are [OK]

Common Mistakes:

• Confusing authentication with data storage
• Thinking authentication speeds up search
• Mixing authentication with backup processes

2. Which of the following is the correct way to call the Elasticsearch API to check your authentication status?

easy

A. GET /_cluster/_health

B. POST /_search/_authenticate

C. PUT /_security/_authenticate

D. GET /_security/_authenticate

Solution

1. Step 1: Identify the correct API endpoint for authentication

   The correct endpoint to verify identity is _security/_authenticate with GET method.

2. Step 2: Check HTTP method correctness

   Authentication check uses GET, not POST or PUT.

3. Final Answer:

   GET /_security/_authenticate -> Option D

4. Quick Check:

   Use GET on _security/_authenticate [OK]

Hint: Use GET method on _security/_authenticate [OK]

Common Mistakes:

• Using POST or PUT instead of GET
• Calling wrong API like _search or _cluster
• Misspelling the endpoint path

3. What will be the result of this curl command if the credentials are correct?

curl -u elastic:changeme -X GET "localhost:9200/_security/_authenticate"

medium

A. An error message saying 'Unauthorized'

B. A JSON response with user details and roles

C. A list of all indices in the cluster

D. A blank response with status 200

Solution

1. Step 1: Understand the curl command

   The command uses basic auth with username 'elastic' and password 'changeme' to call the authenticate API.

2. Step 2: Predict the API response on correct credentials

   If credentials are correct, the API returns JSON with user info and roles, not errors or unrelated data.

3. Final Answer:

   A JSON response with user details and roles -> Option B

4. Quick Check:

   Correct credentials = user info JSON [OK]

Hint: Correct credentials return user info JSON [OK]

Common Mistakes:

• Expecting an error with correct credentials
• Confusing authenticate API with index listing
• Assuming blank response means success

4. You run this command but get an 'Unauthorized' error:

curl -X GET "localhost:9200/_security/_authenticate"

What is the most likely cause?

medium

A. You forgot to include authentication credentials

B. The Elasticsearch cluster is down

C. The API endpoint is incorrect

D. The curl command syntax is invalid

Solution

1. Step 1: Analyze the curl command

   The command calls the authenticate API but does not provide any credentials.

2. Step 2: Understand why 'Unauthorized' occurs

   Without credentials, Elasticsearch denies access, causing 'Unauthorized' error.

3. Final Answer:

   You forgot to include authentication credentials -> Option A

4. Quick Check:

   Missing credentials cause Unauthorized error [OK]

Hint: Always include credentials for secure APIs [OK]

Common Mistakes:

• Assuming cluster is down without checking
• Thinking API endpoint is wrong
• Believing curl syntax is incorrect

5. You want to create an API key for authentication in Elasticsearch using this request:

POST /_security/api_key
{"name": "my-key", "role_descriptors": {"my-role": {"cluster": ["all"]}}}

What is the correct way to authenticate this request?

hard

A. Use basic authentication with a user having the 'manage_api_key' privilege

B. No authentication is needed to create API keys

C. Use the API key itself in the request header

D. Use anonymous access enabled in Elasticsearch

Solution

1. Step 1: Understand API key creation requirements

   Creating API keys requires authentication with a user having 'manage_api_key' privilege.

2. Step 2: Identify correct authentication method

   Basic authentication with such a user is needed; API key or anonymous access won't work for creation.

3. Final Answer:

   Use basic authentication with a user having the 'manage_api_key' privilege -> Option A

4. Quick Check:

   API key creation requires privileged user auth [OK]

Hint: API key creation needs privileged user auth [OK]

Common Mistakes:

• Trying to create API key without authentication
• Using API key before it exists
• Assuming anonymous access allows API key creation