Function deployment and testing in GCP - Mini Project: Build & Apply

Function deployment and testing

📖 Scenario: You are working on a cloud project where you need to deploy a simple Google Cloud Function that responds with a greeting message. You will create the function code, configure deployment settings, deploy the function, and then test it to ensure it works correctly.

🎯 Goal: Build and deploy a Google Cloud Function named helloWorld that returns a greeting message. Then configure the function to allow unauthenticated access and test it by invoking it using the Google Cloud CLI.

📋 What You'll Learn

Create a Python function named helloWorld that returns the string 'Hello, Cloud!'

Create a deployment configuration specifying the runtime as Python 3.9 and the entry point as helloWorld

Deploy the function to Google Cloud with the name helloWorld in the us-central1 region

Allow unauthenticated invocations of the deployed function

Test the deployed function by invoking it using the gcloud CLI command

💡 Why This Matters

🌍 Real World

Cloud Functions let developers run code in response to events without managing servers. Deploying and testing functions is a common task in cloud projects.

💼 Career

Knowing how to deploy and test cloud functions is essential for cloud engineers, developers, and DevOps professionals working with serverless architectures.

1

Create the Cloud Function code

Create a Python function named helloWorld that takes request as a parameter and returns the string 'Hello, Cloud!'.

GCP

# Your code here

Hint

Define a function named helloWorld with one parameter request. Return the greeting string.

2

Create deployment configuration

Create a variable named deployment_config as a dictionary with keys runtime set to 'python39' and entry_point set to 'helloWorld'.

GCP

def helloWorld(request):
    return 'Hello, Cloud!'

# Your code here

Hint

Create a dictionary named deployment_config with the specified keys and values.

3

Deploy the Cloud Function

Write a shell command string named deploy_command that deploys the function helloWorld to the us-central1 region using the runtime and entry point from deployment_config. The command should use gcloud functions deploy with flags --runtime, --entry-point, and --region.

GCP

def helloWorld(request):
    return 'Hello, Cloud!'

deployment_config = {
    'runtime': 'python39',
    'entry_point': 'helloWorld'
}

# Your code here

Hint

Use an f-string to build the deploy command using values from deployment_config. Include --trigger-http and --allow-unauthenticated flags.

4

Test the deployed function

Write a shell command string named test_command that invokes the deployed function helloWorld in the us-central1 region using gcloud functions call.

GCP

def helloWorld(request):
    return 'Hello, Cloud!'

deployment_config = {
    'runtime': 'python39',
    'entry_point': 'helloWorld'
}

deploy_command = f"gcloud functions deploy helloWorld --runtime {deployment_config['runtime']} --entry-point {deployment_config['entry_point']} --region us-central1 --trigger-http --allow-unauthenticated"

# Your code here

Hint

Create a string named test_command with the exact gcloud CLI call command to invoke the function.

Practice

1. What does deploying a Cloud Function in GCP mean?

easy

A. Uploading your code to the cloud so it can run when needed

B. Writing code on your local computer only

C. Deleting old versions of your code

D. Running your code only on your personal device

Solution

1. Step 1: Understand deployment meaning

   Deployment means putting your code on the cloud so it can be accessed and run remotely.

2. Step 2: Compare options

   Only Uploading your code to the cloud so it can run when needed describes uploading code to the cloud to run on demand, which matches deployment.

3. Final Answer:

   Uploading your code to the cloud so it can run when needed -> Option A

4. Quick Check:

   Deploy = Upload code to cloud [OK]

Hint: Deployment means putting code on cloud to run [OK]

Common Mistakes:

• Confusing deployment with local coding
• Thinking deployment deletes code
• Assuming deployment runs code only locally

2. Which command correctly deploys a Cloud Function named helloWorld with runtime python39 and trigger HTTP?

easy

A. gcloud functions run helloWorld --runtime python39 --trigger-http

B. gcloud deploy function helloWorld --runtime python39 --trigger-http

C. gcloud functions create helloWorld --runtime python39 --trigger-http

D. gcloud functions deploy helloWorld --runtime python39 --trigger-http

Solution

1. Step 1: Recall correct deploy syntax

   The correct command starts with 'gcloud functions deploy' followed by the function name and flags.

2. Step 2: Check options

   Only gcloud functions deploy helloWorld --runtime python39 --trigger-http uses 'gcloud functions deploy' with correct flags for runtime and trigger.

3. Final Answer:

   gcloud functions deploy helloWorld --runtime python39 --trigger-http -> Option D

4. Quick Check:

   Deploy command = 'gcloud functions deploy' [OK]

Hint: Deploy uses 'gcloud functions deploy' command [OK]

Common Mistakes:

• Using 'create' instead of 'deploy'
• Using 'run' instead of 'deploy'
• Wrong command order or missing flags

3. Given this deployment command:

gcloud functions deploy greetUser --runtime nodejs18 --trigger-http --allow-unauthenticated

What is the effect of the --allow-unauthenticated flag?

medium

A. Only authenticated users can call the function

B. Anyone can call the function without signing in

C. The function will not be deployed

D. The function will require a password to run

Solution

1. Step 1: Understand the flag meaning

   The flag '--allow-unauthenticated' means the function can be called by anyone without login.

2. Step 2: Match options

   Anyone can call the function without signing in correctly states that anyone can call the function without signing in.

3. Final Answer:

   Anyone can call the function without signing in -> Option B

4. Quick Check:

   Allow unauthenticated = open access [OK]

Hint: Allow unauthenticated means open access [OK]

Common Mistakes:

• Thinking it restricts access
• Confusing with authentication required
• Assuming it blocks deployment

4. You deployed a function but get an error when testing it. Which of these is a common cause?

medium

A. The function name in the deploy command does not match the code's exported function

B. You used the correct runtime but forgot to deploy

C. The function was deployed with the correct trigger and runs fine

D. You tested the function before writing any code

Solution

1. Step 1: Identify common deployment error

   If the deployed function name does not match the exported function in code, it causes errors on test.

2. Step 2: Evaluate options

   The function name in the deploy command does not match the code's exported function correctly points out this mismatch as a common cause of errors.

3. Final Answer:

   The function name in the deploy command does not match the code's exported function -> Option A

4. Quick Check:

   Name mismatch causes test errors [OK]

Hint: Match deploy name with exported function name [OK]

Common Mistakes:

• Ignoring function name mismatch
• Assuming deployment without code causes errors
• Testing before code exists

5. You want to deploy a function that triggers on new files in a Cloud Storage bucket named my-bucket. Which command correctly sets this trigger?

hard

A. gcloud functions deploy processFile --runtime python39 --trigger-http

B. gcloud functions deploy processFile --runtime python39 --trigger-topic my-bucket

C. gcloud functions deploy processFile --runtime python39 --trigger-resource my-bucket --trigger-event google.storage.object.finalize

D. gcloud functions deploy processFile --runtime python39 --trigger-bucket my-bucket

Solution

1. Step 1: Identify correct trigger for Cloud Storage

   Cloud Storage triggers use '--trigger-resource' with bucket name and '--trigger-event' with event type like 'google.storage.object.finalize'.

2. Step 2: Check options

   gcloud functions deploy processFile --runtime python39 --trigger-resource my-bucket --trigger-event google.storage.object.finalize correctly uses '--trigger-resource my-bucket' and '--trigger-event google.storage.object.finalize'. Others use wrong triggers.

3. Final Answer:

   gcloud functions deploy processFile --runtime python39 --trigger-resource my-bucket --trigger-event google.storage.object.finalize -> Option C

4. Quick Check:

   Storage trigger = resource + event flags [OK]

Hint: Use --trigger-resource and --trigger-event for storage triggers [OK]

Common Mistakes:

• Using --trigger-http for storage events
• Using --trigger-topic instead of resource/event
• Using non-existent --trigger-bucket flag