NodePort service type in Kubernetes - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a NodePort service in Kubernetes.

Kubernetes

apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  type: [1]
  selector:
    app: MyApp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 9376

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

ANodePort

BLoadBalancer

CClusterIP

DExternalName

Attempts:

3 left

💡 Hint

Common Mistakes

Using ClusterIP instead of NodePort will not expose the service outside the cluster.

LoadBalancer is used for cloud providers, not basic NodePort exposure.

The type field set to NodePort exposes the service on each Node's IP at a static port.

2fill in blank

medium

Complete the code to specify the port number for the NodePort service.

Kubernetes

apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  type: NodePort
  selector:
    app: MyApp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 9376
      nodePort: [1]

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

A80

B30000

C8080

D22

Attempts:

3 left

💡 Hint

Common Mistakes

Setting nodePort to 80 or 22 will cause errors because those ports are reserved.

Choosing a port outside the 30000-32767 range is invalid.

The nodePort must be a port number between 30000 and 32767 for NodePort services.

3fill in blank

hard

Fix the error in the service definition by completing the missing field.

Kubernetes

apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  type: NodePort
  selector:
    app: MyApp
  ports:
    - protocol: TCP
      port: 80
      [1]: 9376
      nodePort: 30001

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

AtargetPort

BportNumber

CtargetPortNumber

DcontainerPort

Attempts:

3 left

💡 Hint

Common Mistakes

Using portNumber instead of targetPort causes the service to fail.

Confusing containerPort with targetPort in the service spec.

The correct field to specify the port on the pod is targetPort.

4fill in blank

hard

Fill both blanks to complete the NodePort service ports configuration.

Kubernetes

ports:
  - protocol: [1]
    port: [2]
    targetPort: 8080
    nodePort: 30010

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

ATCP

BUDP

C80

D443

Attempts:

3 left

💡 Hint

Common Mistakes

Using UDP protocol for HTTP services is incorrect.

Setting port to 443 without TLS configuration is confusing.

The protocol is usually TCP and the service port is commonly 80 for HTTP.

5fill in blank

hard

Fill all three blanks to complete the NodePort service YAML snippet.

Kubernetes

apiVersion: v1
kind: Service
metadata:
  name: example-service
spec:
  type: [1]
  selector:
    app: example
  ports:
    - protocol: [2]
      port: [3]
      targetPort: 5000
      nodePort: 31000

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

ANodePort

BTCP

C80

DClusterIP

Attempts:

3 left

💡 Hint

Common Mistakes

Using ClusterIP instead of NodePort will not expose the service externally.

Using UDP protocol for HTTP services is incorrect.

Setting port to 5000 instead of 80 changes the exposed port.

The service type must be NodePort, protocol TCP, and port 80 to expose the app on port 80 via NodePort.

Practice

1. What does a Kubernetes NodePort service do?

easy

A. Exposes the service on a static port on each node's IP address

B. Creates an internal cluster IP only accessible inside the cluster

C. Routes traffic through an external load balancer automatically

D. Runs the service only on a single node in the cluster

Solution

1. Step 1: Understand NodePort service purpose

   A NodePort service exposes the application on a fixed port on every node's IP, allowing external access.

2. Step 2: Compare with other service types

   ClusterIP is internal only, LoadBalancer uses external balancers, and NodePort is not limited to a single node.

3. Final Answer:

   Exposes the service on a static port on each node's IP address -> Option A

4. Quick Check:

   NodePort = fixed port on all nodes [OK]

Hint: NodePort always opens a fixed port on every node IP [OK]

Common Mistakes:

• Confusing NodePort with ClusterIP (internal only)
• Thinking NodePort uses external load balancers automatically
• Assuming NodePort restricts service to one node

2. Which of the following is the correct YAML snippet to define a NodePort service?

easy

A. apiVersion: v1\nkind: Pod\nmetadata:\n name: my-service\nspec:\n containers:\n - name: app\n image: my-app-image

B. apiVersion: v1\nkind: Service\nmetadata:\n name: my-service\nspec:\n type: ClusterIP\n selector:\n app: my-app\n ports:\n - port: 80\n targetPort: 8080\n nodePort: 30007

C. apiVersion: v1\nkind: Service\nmetadata:\n name: my-service\nspec:\n type: NodePort\n selector:\n app: my-app\n ports:\n - port: 80\n targetPort: 8080\n nodePort: 30007

D. apiVersion: v1\nkind: Service\nmetadata:\n name: my-service\nspec:\n type: LoadBalancer\n selector:\n app: my-app\n ports:\n - port: 80\n targetPort: 8080\n nodePort: 30007

Solution

1. Step 1: Identify correct service type

   The service type must be NodePort to expose on a node port.

2. Step 2: Check YAML structure and fields

   The YAML must define kind: Service, type: NodePort, and specify nodePort under ports.

3. Final Answer:

   YAML with type NodePort and nodePort field -> Option C

4. Quick Check:

   NodePort type + nodePort field = correct YAML [OK]

Hint: NodePort service YAML must have type: NodePort and nodePort set [OK]

Common Mistakes:

• Using ClusterIP or LoadBalancer instead of NodePort
• Defining nodePort in a Pod instead of Service
• Missing the nodePort field in ports

3. Given this NodePort service YAML, what port will you use to access the app externally?

apiVersion: v1
kind: Service
metadata:
  name: example-service
spec:
  type: NodePort
  selector:
    app: example
  ports:
    - port: 80
      targetPort: 8080
      nodePort: 31000

medium

A. Port 31000 on the node IP

B. Port 80 on the node IP

C. Port 8080 on the node IP

D. Port 80 on the pod IP

Solution

1. Step 1: Understand NodePort port usage

   The nodePort field defines the port exposed on each node's IP for external access.

2. Step 2: Identify the correct port from YAML

   The YAML sets nodePort: 31000, so external access uses port 31000 on any node IP.

3. Final Answer:

   Port 31000 on the node IP -> Option A

4. Quick Check:

   External access uses nodePort value = 31000 [OK]

Hint: Use the nodePort value to access service externally [OK]

Common Mistakes:

• Using targetPort or port instead of nodePort externally
• Trying to access pod IP directly
• Confusing port and nodePort fields

4. You created a NodePort service but cannot access your app externally. Which is the most likely cause?

medium

A. The pod selector labels do not match any pods

B. All of the above

C. The service type is set to ClusterIP instead of NodePort

D. The nodePort value is outside the allowed range (30000-32767)

Solution

1. Step 1: Check nodePort range validity

   NodePort must be between 30000 and 32767; outside this range causes failure.

2. Step 2: Verify pod selector and service type

   If selector labels don't match pods or service type is not NodePort, external access fails.

3. Step 3: Combine all issues

   Any of these issues can cause access failure, so all are likely causes.

4. Final Answer:

   All of the above -> Option B

5. Quick Check:

   Invalid port, selector, or type = no external access [OK]

Hint: Check port range, selector labels, and service type [OK]

Common Mistakes:

• Ignoring nodePort range limits
• Not verifying pod labels match selector
• Assuming service type is correct without checking

5. You want to expose a web app on port 80 inside the cluster and port 32000 externally using NodePort. Which YAML snippet correctly achieves this?

hard

A. apiVersion: v1\nkind: Service\nmetadata:\n name: webapp-service\nspec:\n type: ClusterIP\n selector:\n app: webapp\n ports:\n - port: 80\n targetPort: 80\n nodePort: 32000

B. apiVersion: v1\nkind: Service\nmetadata:\n name: webapp-service\nspec:\n type: LoadBalancer\n selector:\n app: webapp\n ports:\n - port: 32000\n targetPort: 80\n nodePort: 80

C. apiVersion: v1\nkind: Service\nmetadata:\n name: webapp-service\nspec:\n type: NodePort\n selector:\n app: webapp\n ports:\n - port: 32000\n targetPort: 32000\n nodePort: 80

D. apiVersion: v1\nkind: Service\nmetadata:\n name: webapp-service\nspec:\n type: NodePort\n selector:\n app: webapp\n ports:\n - port: 80\n targetPort: 80\n nodePort: 32000

Solution

1. Step 1: Match internal and external ports correctly

   The port is the internal cluster port (80), targetPort is the container port (80), and nodePort is the external port (32000).

2. Step 2: Verify service type and port fields

   Service type must be NodePort and ports must be set accordingly to expose externally on 32000.

3. Final Answer:

   YAML with type NodePort, port 80, targetPort 80, nodePort 32000 -> Option D

4. Quick Check:

   NodePort type + nodePort 32000 + port 80 = correct setup [OK]

Hint: Set port=internal, targetPort=container, nodePort=external port [OK]

Common Mistakes:

• Swapping port and nodePort values
• Using LoadBalancer or ClusterIP instead of NodePort
• Setting nodePort outside allowed range