Why serverless patterns matter in GCP - See It in Action

Why Serverless Patterns Matter

📖 Scenario: You are working for a small startup that wants to build a simple web application. The team wants to use cloud services that automatically handle scaling and reduce the need to manage servers. You will learn how to set up a basic serverless function and understand why using serverless patterns is helpful.

🎯 Goal: Build a simple serverless function on Google Cloud Platform (GCP) that responds to HTTP requests. Learn how serverless patterns help by automatically scaling and reducing infrastructure management.

📋 What You'll Learn

Create a basic HTTP Cloud Function in GCP

Add a configuration variable to control a greeting message

Implement the function logic to return the greeting message

Deploy the function with the correct entry point and runtime

💡 Why This Matters

🌍 Real World

Serverless functions let developers focus on code without managing servers. They automatically scale with demand, saving time and cost.

💼 Career

Understanding serverless patterns is essential for cloud engineers and developers working with modern cloud platforms like GCP, AWS, or Azure.

1

Create the initial Cloud Function code

Create a Python function called hello_world that takes request as a parameter and returns the string 'Hello, Serverless!'.

GCP

# Define the hello_world function that returns 'Hello, Serverless!'
# Your code here

Hint

Define a function named hello_world with one parameter request. Return the exact string 'Hello, Serverless!'.

2

Add a greeting message configuration variable

Add a variable called GREETING and set it to the string 'Welcome to Serverless Patterns' above the hello_world function.

GCP

GREETING = ''  # Set the greeting message here

def hello_world(request):
    return 'Hello, Serverless!'
# Your code here

Hint

Define the variable GREETING before the function with the exact string value.

3

Use the greeting variable in the function

Change the hello_world function to return the value of the GREETING variable instead of the fixed string.

GCP

GREETING = 'Welcome to Serverless Patterns'

def hello_world(request):
    # Return the GREETING variable
    
# Your code here

Hint

Replace the return statement to return the GREETING variable.

4

Add deployment configuration for the Cloud Function

Add a comment at the top specifying the runtime as python39 and the entry point as hello_world to prepare for deployment.

GCP

# Runtime: python39
# Entry point: hello_world

GREETING = 'Welcome to Serverless Patterns'

def hello_world(request):
    return GREETING
# Your code here

Hint

Add comments at the top exactly as shown to indicate runtime and entry point.

Practice

1. What is the main benefit of using serverless patterns in cloud applications?

easy

A. Fixed monthly billing regardless of usage

B. Manual control over server hardware

C. Automatic scaling without managing servers

D. Requires setting up virtual machines

Solution

1. Step 1: Understand serverless basics

   Serverless means the cloud provider manages servers, so you don't have to.

2. Step 2: Identify key benefit

   Serverless apps scale automatically based on demand without manual server management.

3. Final Answer:

   Automatic scaling without managing servers -> Option C

4. Quick Check:

   Serverless = automatic scaling [OK]

Hint: Serverless means no server setup needed [OK]

Common Mistakes:

• Thinking serverless means no servers exist
• Assuming fixed billing regardless of usage
• Confusing serverless with manual server control

2. Which of the following is the correct way to define a Cloud Function trigger in GCP serverless pattern?

easy

A. trigger: http

B. trigger: virtual_machine

C. trigger: manual_start

D. trigger: database_backup

Solution

1. Step 1: Recall Cloud Function triggers

   Cloud Functions commonly trigger on HTTP requests or events, not manual or VM triggers.

2. Step 2: Identify valid trigger

   trigger: http is the correct syntax for HTTP-triggered functions.

3. Final Answer:

   <code>trigger: http</code> -> Option A

4. Quick Check:

   HTTP trigger syntax = correct [OK]

Hint: Cloud Functions trigger on events like HTTP [OK]

Common Mistakes:

• Using triggers that don't exist like manual_start
• Confusing VM triggers with serverless triggers
• Assuming database_backup is a trigger

3. Given this serverless function code snippet in GCP:

def hello_world(event, context):
    print('Hello, world!')

What happens when this function is deployed and triggered by an event?

medium

A. The function prints 'Hello, world!' to the logs

B. The function returns 'Hello, world!' to the caller

C. The function fails because of missing return statement

D. The function runs only once and then stops

Solution

1. Step 1: Understand function behavior

   The function prints a message to logs when triggered; no return value is needed.

2. Step 2: Identify output

   Print statements appear in logs, not as return to caller.

3. Final Answer:

   The function prints 'Hello, world!' to the logs -> Option A

4. Quick Check:

   Print output = logs [OK]

Hint: Print outputs go to logs, not caller [OK]

Common Mistakes:

• Expecting print to return value to caller
• Thinking missing return causes failure
• Assuming function runs only once

4. You deployed a serverless function but it never triggers on new file uploads to Cloud Storage. What is the most likely cause?

medium

A. The function code has syntax errors

B. The function trigger is not set to Cloud Storage events

C. The Cloud Storage bucket is empty

D. The function is set to manual trigger only

Solution

1. Step 1: Check trigger configuration

   For automatic runs on file uploads, the function must have a Cloud Storage event trigger.

2. Step 2: Identify cause of no trigger

   If trigger is missing or incorrect, function won't run on uploads.

3. Final Answer:

   The function trigger is not set to Cloud Storage events -> Option B

4. Quick Check:

   Trigger mismatch = no function run [OK]

Hint: Check event trigger matches source action [OK]

Common Mistakes:

• Assuming empty bucket stops triggers
• Blaming code errors without checking triggers
• Confusing manual trigger with event trigger

5. You want to build a serverless app that processes images uploaded to Cloud Storage and stores metadata in Firestore. Which serverless pattern best fits this use case?

hard

A. Using a scheduled job to scan the bucket every hour

B. Manual invocation of functions via HTTP requests

C. Running a VM continuously to watch the bucket

D. Event-driven functions triggered by Cloud Storage events

Solution

1. Step 1: Analyze use case requirements

   The app needs to react immediately to image uploads and process them.

2. Step 2: Match pattern to requirement

   Event-driven functions triggered by Cloud Storage events run code automatically on uploads.

3. Step 3: Evaluate other options

   Manual HTTP triggers, VMs, or scheduled jobs are less efficient or not real-time.

4. Final Answer:

   Event-driven functions triggered by Cloud Storage events -> Option D

5. Quick Check:

   Event-driven = automatic, real-time processing [OK]

Hint: Use event triggers for real-time processing [OK]

Common Mistakes:

• Choosing manual triggers for automatic events
• Using VMs instead of serverless functions
• Relying on scheduled jobs for immediate processing