Prometheus exporter in Nginx - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Prometheus Nginx Exporter Metrics Endpoint Output

You have configured the Prometheus Nginx exporter to expose metrics at http://localhost:9113/metrics. What is the expected output when you curl this endpoint?

Nginx

curl http://localhost:9113/metrics

A A binary file download containing compressed metrics data

B A JSON object with keys 'active_connections' and 'total_requests' showing numeric values

C A plain text list of metrics including lines like 'nginx_connections_active 5' and 'nginx_http_requests_total 12345'

D An HTML page showing graphs of Nginx metrics

💡 Hint

Prometheus exporters expose metrics in a simple text format for scraping.

Prometheus exporters expose metrics as plain text with metric names and values, not JSON or HTML.

❓ Configuration

intermediate

Configuring Nginx for Prometheus Exporter

Which Nginx configuration snippet correctly enables the stub_status module at /nginx_status for Prometheus exporter scraping?

A location /nginx_status { stub_status; allow 127.0.0.1; deny all; }

B location /nginx_status { return 404; }

C location /nginx_status { proxy_pass http://localhost:9113; }

D location /nginx_status { autoindex on; }

💡 Hint

The stub_status directive provides basic Nginx metrics.

The stub_status directive enables Nginx to expose metrics at the specified location, allowing Prometheus exporter to scrape them.

❓ Troubleshoot

advanced

Prometheus Exporter Fails to Scrape Nginx Metrics

You configured Prometheus to scrape Nginx metrics from http://localhost:9113/metrics, but no data appears in Prometheus. What is the most likely cause?

A The Nginx stub_status endpoint is not enabled or accessible

B Prometheus server is not running on port 9113

C Nginx is running on a different server than Prometheus exporter

D Prometheus uses JSON format but exporter provides plain text

💡 Hint

Check if Nginx exposes metrics for the exporter to collect.

If the stub_status endpoint is not enabled or blocked, the exporter cannot collect metrics, so Prometheus sees no data.

🔀 Workflow

advanced

Steps to Add Nginx Metrics to Prometheus Monitoring

What is the correct order of steps to add Nginx metrics to Prometheus using the Prometheus Nginx exporter?

A 1,4,2,3

B 1,2,4,3

C 2,1,3,4

D 1,2,3,4

💡 Hint

Think about enabling metrics first, then running exporter, then configuring Prometheus.

First enable stub_status, then run exporter to collect metrics, then configure Prometheus to scrape, finally reload services.

✅ Best Practice

expert

Securing Nginx Metrics Endpoint for Prometheus Exporter

Which method is the best practice to secure the Nginx stub_status endpoint exposed for Prometheus scraping?

A Use basic authentication with a username and password

B Allow access only from Prometheus server IP and deny all others

C Expose the endpoint publicly without restrictions for easy access

D Disable stub_status and rely on logs for metrics

💡 Hint

Limit access to trusted sources only.

Restricting access by IP ensures only Prometheus can scrape metrics, reducing security risks.