Nginx Plus monitoring - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Nginx Plus status endpoint output

What is the output of the following curl command when querying the Nginx Plus status endpoint configured at /status?

Nginx

curl -s http://localhost/status

A {"connections":{"active":10,"waiting":5,"reading":2,"writing":3},"server_zones":{"example.com":{"requests":1000,"responses":{"1xx":0,"2xx":950,"3xx":30,"4xx":15,"5xx":5}}}}

B {"error":"Not Found"}

C curl: (7) Failed to connect to localhost port 80: Connection refused

D <html><body>Status Page</body></html>

💡 Hint

Nginx Plus status endpoint returns JSON with connection and server zone metrics.

The Nginx Plus status endpoint returns a JSON object with detailed metrics about connections and server zones. Option A matches this expected JSON structure.

🧠 Conceptual

intermediate

Purpose of Nginx Plus API

What is the primary purpose of the Nginx Plus API in monitoring?

A To serve static website content faster

B To provide real-time metrics and configuration management via a RESTful interface

C To replace the need for a load balancer

D To encrypt all HTTP traffic automatically

💡 Hint

Think about how monitoring tools get data from Nginx Plus.

The Nginx Plus API offers a RESTful interface that provides real-time metrics and allows dynamic configuration changes, which is essential for monitoring and management.

❓ Troubleshoot

advanced

Diagnosing missing Nginx Plus status metrics

You configured the Nginx Plus status endpoint at /status but receive a 404 error when accessing it. What is the most likely cause?

A The SSL certificate expired

B The server is overloaded and cannot respond

C The firewall is blocking port 443

D The <code>status</code> directive is missing or misconfigured in the Nginx configuration

💡 Hint

Check the Nginx configuration for the status endpoint setup.

If the status endpoint returns 404, it usually means the status directive or location block is missing or incorrect in the Nginx config.

🔀 Workflow

advanced

Steps to enable Nginx Plus monitoring API

Which sequence correctly describes the steps to enable the Nginx Plus monitoring API?

A 1,3,2,4

B 2,1,3,4

C 1,2,3,4

D 3,2,1,4

💡 Hint

Think about installation first, then configuration, then reload.

You must first install Nginx Plus, then configure the status directive and location, and finally reload Nginx to enable the monitoring API.

✅ Best Practice

expert

Best practice for securing Nginx Plus status endpoint

What is the best practice to secure access to the Nginx Plus status endpoint?

A Restrict access to trusted IP addresses and use basic authentication

B Make the status endpoint publicly accessible for easy monitoring

C Disable the status endpoint entirely to avoid any risk

D Use HTTP instead of HTTPS to simplify access

💡 Hint

Think about limiting who can see sensitive metrics.

Securing the status endpoint by restricting IPs and requiring authentication prevents unauthorized access to sensitive server metrics.

Practice

1. What is the main purpose of the Nginx Plus monitoring API endpoint?

easy

A. To provide live data about server traffic and health

B. To serve static website files

C. To configure SSL certificates automatically

D. To block unwanted IP addresses

Solution

1. Step 1: Understand Nginx Plus monitoring role

   Nginx Plus monitoring API endpoint is designed to show live server data such as traffic, errors, and health.

2. Step 2: Identify the correct purpose

   Serving static files, configuring SSL, or blocking IPs are unrelated to monitoring API.

3. Final Answer:

   To provide live data about server traffic and health -> Option A

4. Quick Check:

   Monitoring API = live server data [OK]

Hint: Monitoring API shows live server info, not config or files [OK]

Common Mistakes:

• Confusing monitoring API with static file serving
• Thinking it manages SSL certificates
• Assuming it blocks IP addresses

2. Which configuration snippet correctly enables Nginx Plus monitoring API at the path /api?

easy

A. location /api { api; }

B. location /api { proxy_pass http://backend; }

C. location /api { return 404; }

D. location /api { root /var/www/html; }

Solution

1. Step 1: Recall correct syntax for enabling Nginx Plus API

   The directive api; inside a location block enables the monitoring API endpoint.

2. Step 2: Compare options

   Only location /api { api; } uses api; directive. Others proxy, return 404, or serve files, which do not enable monitoring API.

3. Final Answer:

   location /api { api; } -> Option A

4. Quick Check:

   Enable API = location with api; directive [OK]

Hint: Use 'location /api { api; }' to enable monitoring [OK]

Common Mistakes:

• Using proxy_pass instead of api directive
• Returning 404 disables the endpoint
• Serving files does not enable API

3. Given this Nginx Plus config snippet, what will be the output when accessing /api?

location /api {
    api;
}

medium

A. A 404 Not Found error

B. A JSON response with live server metrics

C. The contents of /api directory on disk

D. A redirect to another URL

Solution

1. Step 1: Understand the api; directive effect

   The api; directive enables the Nginx Plus monitoring API, which returns live server data in JSON format.

2. Step 2: Analyze the response type

   Accessing /api returns JSON with metrics, not a 404, file contents, or redirect.

3. Final Answer:

   A JSON response with live server metrics -> Option B

4. Quick Check:

   api; returns JSON metrics [OK]

Hint: api; returns JSON live metrics at /api [OK]

Common Mistakes:

• Expecting file contents instead of JSON
• Thinking it returns 404 error
• Assuming it redirects

4. You added this config to enable Nginx Plus monitoring but get a 404 error when accessing /api:

location /api {
    api
}

What is the likely cause?

medium

A. The api directive requires a parameter

B. Wrong location path, should be /monitor

C. Nginx Plus monitoring is not supported on this server

D. Missing semicolon after api directive

Solution

1. Step 1: Check syntax of the api directive

   The api directive must end with a semicolon (api;). Missing it causes config errors and 404 responses.

2. Step 2: Evaluate other options

   The location path /api is correct, monitoring is supported, and api directive takes no parameters.

3. Final Answer:

   Missing semicolon after api directive -> Option D

4. Quick Check:

   Directive missing semicolon = 404 error [OK]

Hint: Always end directives with semicolon ; [OK]

Common Mistakes:

• Omitting semicolon after api directive
• Changing location path unnecessarily
• Assuming api directive needs parameters

5. You want to monitor multiple Nginx Plus servers centrally. Which approach using the monitoring API is best?

hard

A. Use location /api { proxy_pass http://backend; } to forward monitoring requests

B. Set up a single Nginx Plus server with location /api { api; } and proxy all traffic through it

C. Configure each server with location /api { api; } and use a script to fetch JSON from each server's /api endpoint

D. Disable the monitoring API and use log files only

Solution

1. Step 1: Understand monitoring API usage per server

   Each Nginx Plus server exposes its own live data at /api when configured with api;.

2. Step 2: Centralize monitoring by fetching data

   A script or tool can query each server's /api endpoint to collect and aggregate metrics centrally.

3. Step 3: Evaluate other options

   Proxying all traffic through one server or disabling API loses direct live data. Proxy_pass does not enable monitoring API.

4. Final Answer:

   Configure each server with location /api { api; } and use a script to fetch JSON from each server's /api endpoint -> Option C

5. Quick Check:

   Each server exposes API; central script collects data [OK]

Hint: Enable api; on each server, fetch data centrally via script [OK]

Common Mistakes:

• Trying to proxy monitoring API through one server
• Disabling API and relying only on logs
• Misusing proxy_pass for monitoring API