Function deployment and testing in GCP - Step-by-Step Execution

Process Flow - Function deployment and testing

Write function code

↓

Package code and dependencies

↓

Deploy function to GCP

↓

Trigger function (HTTP, event)

↓

Function executes

↓

Check logs and output

↓

Fix issues or confirm success

This flow shows how you write, deploy, trigger, and test a cloud function on GCP step-by-step.

Execution Sample

GCP

gcloud functions deploy helloWorld --runtime python312 --trigger-http --allow-unauthenticated

# Then test with:
curl https://REGION-PROJECT.cloudfunctions.net/helloWorld

Deploy a simple HTTP-triggered Python function and test it by sending an HTTP request.

Process Table

Step	Action	Input/Command	Result/Output
1	Write function code	def helloWorld(request): return 'Hello, World!'	Function code ready
2	Package and prepare	N/A	Code and dependencies ready for deployment
3	Deploy function	gcloud functions deploy helloWorld --runtime python312 --trigger-http --allow-unauthenticated	Function deployed, URL provided
4	Trigger function	curl https://REGION-PROJECT.cloudfunctions.net/helloWorld	HTTP 200 OK, response: 'Hello, World!'
5	Check logs	gcloud functions logs read helloWorld	Logs show function executed successfully
6	Fix or confirm	N/A	If errors, update code and redeploy; else confirm success

💡 Function tested successfully or redeployed after fixes

Status Tracker

Variable	Start	After Deploy	After Trigger	After Logs Check	Final
function_code	empty	helloWorld function code	helloWorld function code	helloWorld function code	helloWorld function code
deployment_status	not deployed	deployed	deployed	deployed	deployed or redeployed
trigger_response	none	none	'Hello, World!'	'Hello, World!'	'Hello, World!' or error
logs	empty	empty	execution logs	execution logs	logs reviewed

Key Moments - 3 Insights

Why do we need to redeploy the function after fixing code?

Because the deployed function runs the old code until you deploy the new version, as shown in step 6 of the execution_table.

What does the trigger step do in testing?

It sends a request to the deployed function URL to run the function and get the output, as shown in step 4.

Why check logs after triggering the function?

Logs show if the function ran correctly or had errors, helping to debug, as shown in step 5.

Visual Quiz - 3 Questions

Look at the execution_table, what is the output after triggering the function at step 4?

A Deployment URL

B Error message

C 'Hello, World!'

D Empty response

💡 Hint

Check the 'Result/Output' column at step 4 in the execution_table.

At which step do you check if the function executed successfully by reading logs?

A Step 5

B Step 2

C Step 3

D Step 6

💡 Hint

Look for the step mentioning 'Check logs' in the execution_table.

If the function code changes, what must you do next according to the flow?

A Check logs only

B Redeploy the function

C Trigger function again without redeploying

D Delete the function

💡 Hint

Refer to step 6 in the execution_table and key_moments about redeployment.

Concept Snapshot

Function Deployment & Testing on GCP:
1. Write your function code.
2. Deploy using gcloud with runtime and trigger.
3. Trigger function via HTTP or event.
4. Check output and logs.
5. Fix code and redeploy if needed.
Repeat testing until success.

Full Transcript

This visual execution shows how to deploy and test a cloud function on Google Cloud Platform. First, you write the function code. Then you deploy it using the gcloud command specifying runtime and trigger type. After deployment, you trigger the function by sending an HTTP request. The function runs and returns output. You check logs to confirm success or find errors. If errors exist, you fix the code and redeploy. This cycle repeats until the function works correctly.

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