HTTP triggered functions in GCP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

HTTP Function Response Behavior

You deploy a Google Cloud Function triggered by HTTP. The function code is:

def hello_world(request):
    return 'Hello, World!'

What will the HTTP client receive as the response body?

GCP

def hello_world(request):
    return 'Hello, World!'

A The client receives an empty response with status code 204 (No Content).

B The client receives a JSON response with body '"Hello, World!"' and status code 200.

C The client receives a plain text response with body 'Hello, World!' and status code 200.

D The function raises an error because the return type is incorrect.

💡 Hint

Consider what happens when a string is returned directly from a Cloud Function.

Returning a string from a Python HTTP Cloud Function sends that string as the plain text response body with status 200.

❓ Configuration

intermediate

Setting HTTP Trigger Permissions

You want your HTTP triggered Cloud Function to be publicly accessible without authentication. Which IAM role should you grant to allUsers on the function?

A roles/cloudfunctions.invoker

B roles/cloudfunctions.admin

C roles/viewer

D roles/owner

💡 Hint

Think about the minimal permission needed to invoke a Cloud Function.

The roles/cloudfunctions.invoker role allows invoking the function. Granting it to allUsers makes the function public.

❓ Architecture

advanced

Designing Scalable HTTP Cloud Functions

You expect a sudden spike of HTTP requests to your Cloud Function. Which design choice helps ensure your function scales smoothly without cold start delays?

A Keep the function stateless and use minimum dependencies to reduce cold start time.

B Store session data in local memory inside the function instance.

C Use a single global variable to cache data across requests.

D Increase the function timeout to handle longer requests.

💡 Hint

Consider what causes cold starts and how to minimize their impact.

Stateless functions with minimal dependencies start faster and scale better. Local memory or global variables do not persist across instances reliably.

❓ security

advanced

Securing HTTP Cloud Functions with Authentication

You want to restrict your HTTP Cloud Function so only authenticated users from your Google Workspace domain can invoke it. What is the best approach?

A Grant roles/cloudfunctions.invoker to allUsers and rely on IP filtering.

B Make the function public and check the user's email in the request headers.

C Disable authentication and rely on a secret token passed as a query parameter.

D Require users to authenticate with Identity Platform and verify their ID token in the function code.

💡 Hint

Think about secure ways to verify user identity in Cloud Functions.

Using Identity Platform for authentication and verifying ID tokens ensures only authorized users can invoke the function securely.

✅ Best Practice

expert

Optimizing HTTP Cloud Function Cold Start Time

You notice your HTTP Cloud Function has high cold start latency due to large dependencies. Which option will most effectively reduce cold start time?

A Increase the function memory allocation to maximum to speed up startup.

B Use Cloud Functions Gen 2 with container-based deployment and optimize the container image size.

C Add a warm-up HTTP request every minute to keep the function instance alive.

D Rewrite the function in a slower language to reduce startup overhead.

💡 Hint

Consider newer Cloud Functions platforms and deployment methods.

Cloud Functions Gen 2 supports container images, allowing you to optimize dependencies and reduce cold start time effectively.