Google Professional Cloud Network Engineer Question 583
Single answerGoogle Cloud PlatformYour company is hosting a web application on a Google Kubernetes Engine (GKE) cluster. The application needs to expose a backend service on a specific static port (e.g., port 8080) to ensure communication with an external legacy system. How should you configure the port allocation to meet this requirement while ensuring proper traffic routing?
- A
Configure a GKE Service of type 'LoadBalancer' and specify the static port 8080 in the 'targetPort' field.
- B
Configure a GKE Service of type 'NodePort' and specify port 8080 in the 'nodePort' field.
- C
Configure a GKE Service of type 'ClusterIP' and specify port 8080 in the 'port' field.
- D
Configure a GKE Service of type 'ExternalName' and specify port 8080 in the 'externalName' field.
Show answer and explanation
Correct answer: B
Explanation
To meet the requirement of exposing a backend service on a specific static port (e.g., port 8080), you must use a GKE Service of type 'NodePort'. This allows you to manually specify the port value in the 'nodePort' field, ensuring that external systems can reliably connect to the application on the predefined port. Other service types either do not support static port allocation for external traffic or are not designed for exposing services externally.
- A. Incorrect.
Incorrect. While a 'LoadBalancer' service can expose an application externally, it uses dynamically allocated node ports by default unless otherwise specified, and does not allow direct control over the nodePort value.
- B. Correct.
Correct. A 'NodePort' service allows you to manually specify a static port (e.g., 8080) in the 'nodePort' field, ensuring external systems can reliably connect to the application on that specific port.
- C. Incorrect.
Incorrect. A 'ClusterIP' service only exposes the application internally within the cluster, and does not allow direct external access or static port configuration for external communication.
- D. Incorrect.
Incorrect. An 'ExternalName' service is used to map a service to an external DNS name and does not involve port configuration for exposing the application.