Prometheus for metrics collection in Kubernetes - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to expose metrics endpoint in a Kubernetes pod manifest.

Kubernetes

containers:
- name: app
  image: myapp:latest
  ports:
  - containerPort: [1]

Drag options to blanks, or click blank then click option'

A8080

B443

C80

D9090

Attempts:

3 left

💡 Hint

Common Mistakes

Using HTTP port 80 instead of Prometheus metrics port 9090.

Confusing HTTPS port 443 with metrics port.

The default port for Prometheus metrics endpoint is 9090, so the container should expose port 9090.

2fill in blank

medium

Complete the Prometheus scrape config to target Kubernetes pods with label 'app=web'.

Kubernetes

- job_name: 'kubernetes-pods'
  kubernetes_sd_configs:
  - role: pod
  relabel_configs:
  - source_labels: [__meta_kubernetes_pod_label_app]
    action: keep
    regex: [1]

Drag options to blanks, or click blank then click option'

Adatabase

Bweb

Ccache

Dapi

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong label value in regex causing no pods to be scraped.

Confusing label keys with label values.

The regex should match the label value 'web' to scrape pods labeled with app=web.

3fill in blank

hard

Fix the error in the Prometheus service monitor selector to match label 'release=prometheus'.

Kubernetes

selector:
  matchLabels:
    release: [1]

Drag options to blanks, or click blank then click option'

Amonitoring

Bkube-prometheus

Cprometheus

Ddefault

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect release name causing selector to fail.

Typos in label values.

The selector must match the label 'release=prometheus' to find the correct service monitor.

4fill in blank

hard

Fill both blanks to create a Prometheus alert rule that fires when CPU usage is above 80%.

Kubernetes

groups:
- name: cpu_alerts
  rules:
  - alert: HighCPUUsage
    expr: sum(rate(container_cpu_usage_seconds_total[1][5m])) by (pod) [2] 0.8
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: "CPU usage is high"

Drag options to blanks, or click blank then click option'

Anamespace="default"

Bnamespace="kube-system"

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong namespace filter causing no data.

Using '<' instead of '>' causing alert to never fire.

The expression filters metrics for the default namespace and triggers alert when usage is greater than 0.8 (80%).

5fill in blank

hard

Fill all three blanks to create a Prometheus scrape config for a Kubernetes service with port 'metrics' and path '/metrics'.

Kubernetes

- job_name: 'kubernetes-service'
  kubernetes_sd_configs:
  - role: service
  relabel_configs:
  - source_labels: [__meta_kubernetes_service_label_app]
    action: keep
    regex: [1]
  metrics_path: [2]
  scheme: [3]

Drag options to blanks, or click blank then click option'

Awebapp

B/metrics

Chttp

Dhttps

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong label value causing no targets.

Wrong metrics path or scheme causing scrape failures.

The job scrapes services labeled 'webapp' on the '/metrics' path using HTTP scheme.

Practice

1. What is the main purpose of Prometheus in a Kubernetes environment?

easy

A. To deploy applications automatically

B. To collect and store metrics data for monitoring

C. To manage Kubernetes cluster nodes

D. To provide a user interface for Kubernetes

Solution

1. Step 1: Understand Prometheus role

   Prometheus is designed to collect numerical data called metrics from applications and systems.

2. Step 2: Identify its main function in Kubernetes

   In Kubernetes, Prometheus collects metrics to monitor app health and performance.

3. Final Answer:

   To collect and store metrics data for monitoring -> Option B

4. Quick Check:

   Prometheus collects metrics = A [OK]

Hint: Prometheus = metrics collection tool [OK]

Common Mistakes:

• Confusing Prometheus with deployment tools
• Thinking Prometheus manages nodes
• Assuming Prometheus is a UI tool

2. Which Kubernetes resource is used to tell Prometheus which services to monitor?

easy

A. ServiceMonitor

B. PodMonitor

C. ConfigMap

D. Ingress

Solution

1. Step 1: Identify Prometheus monitoring resources

   Prometheus uses special Kubernetes custom resources to know what to watch.

2. Step 2: Recognize ServiceMonitor's role

   ServiceMonitor tells Prometheus which Kubernetes services to scrape metrics from.

3. Final Answer:

   ServiceMonitor -> Option A

4. Quick Check:

   ServiceMonitor selects services for Prometheus [OK]

Hint: ServiceMonitor = tells Prometheus what to watch [OK]

Common Mistakes:

• Confusing PodMonitor with ServiceMonitor
• Using ConfigMap for monitoring targets
• Thinking Ingress controls Prometheus scraping

3. Given this snippet of a ServiceMonitor YAML, what is the scrape interval Prometheus will use?

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: example-monitor
spec:
  endpoints:
  - port: web
    interval: 15s
  selector:
    matchLabels:
      app: example

medium

A. 5 seconds

B. 30 seconds

C. 15 seconds

D. 1 minute

Solution

1. Step 1: Locate the interval field in YAML

   The interval is set under endpoints as 'interval: 15s'.

2. Step 2: Understand interval meaning

   This means Prometheus scrapes metrics every 15 seconds from the specified port.

3. Final Answer:

   15 seconds -> Option C

4. Quick Check:

   interval: 15s means 15 seconds [OK]

Hint: Check 'interval' value under endpoints [OK]

Common Mistakes:

• Ignoring the interval field and guessing default
• Confusing seconds with minutes
• Assuming interval is global, not per endpoint

4. You created a ServiceMonitor but Prometheus is not scraping metrics from your service. Which of these is a likely cause?

medium

A. The ServiceMonitor selector labels do not match the service labels

B. The Prometheus server is not running on the cluster

C. The service port is not exposed in the ServiceMonitor endpoints

D. All of the above

Solution

1. Step 1: Check label matching

   If ServiceMonitor selector labels don't match service labels, Prometheus won't find the service.

2. Step 2: Verify Prometheus server status and endpoint config

   Prometheus must be running and the service port must be correctly specified in endpoints to scrape metrics.

3. Final Answer:

   All of the above -> Option D

4. Quick Check:

   Any mismatch or missing config stops scraping [OK]

Hint: Check labels, server status, and endpoints all match [OK]

Common Mistakes:

• Only checking one cause and ignoring others
• Assuming Prometheus always runs by default
• Forgetting to expose correct port in ServiceMonitor

5. You want Prometheus to scrape metrics from multiple services with different scrape intervals. How should you configure this in Kubernetes?

hard

A. Create separate ServiceMonitor resources for each service with their specific intervals

B. Set a global scrape interval in Prometheus config and ignore ServiceMonitor intervals

C. Create one ServiceMonitor with multiple endpoints, each having its own interval

D. Use a ConfigMap to list all services and intervals for Prometheus

Solution

1. Step 1: Understand ServiceMonitor scope

   Each ServiceMonitor targets services with specific scrape configs; intervals are per endpoint.

2. Step 2: Manage different intervals

   To have different intervals per service, create separate ServiceMonitors with their own intervals.

3. Step 3: Why not other options?

   One ServiceMonitor with multiple endpoints cannot set different intervals per service easily; global config overrides intervals; ConfigMap does not control scraping targets.

4. Final Answer:

   Create separate ServiceMonitor resources for each service with their specific intervals -> Option A

5. Quick Check:

   Separate ServiceMonitors allow different intervals [OK]

Hint: Use separate ServiceMonitors for different intervals [OK]

Common Mistakes:

• Trying to set different intervals in one ServiceMonitor
• Ignoring ServiceMonitor intervals in favor of global config
• Using ConfigMap incorrectly for scraping targets