Workflows for orchestration in GCP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a simple step in a Google Cloud Workflow.

GCP

steps:
  - sayHello:
      call: http.get
      args:
        url: "https://example.com/api/[1]"
      result: response

Drag options to blanks, or click blank then click option'

Aworld

Bhello

Cgreet

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using unrelated words that do not fit the URL path.

The URL path segment should be 'world' to complete the example API call.

2fill in blank

medium

Complete the code to specify the workflow's main entry point.

GCP

main:
  steps:
    - firstStep:
        call: [1]
        args:
          url: "https://example.com"
        result: output

Drag options to blanks, or click blank then click option'

AtriggerEvent

BstartWorkflow

CinitProcess

Dhttp.get

Attempts:

3 left

💡 Hint

Common Mistakes

Using custom function names instead of built-in calls.

The 'http.get' call is used to make an HTTP GET request in a workflow step.

3fill in blank

hard

Fix the error in the step that calls a Cloud Function.

GCP

steps:
  - callFunction:
      call: [1]
      args:
        name: projects/my-project/locations/us-central1/functions/myFunction
      result: functionResponse

Drag options to blanks, or click blank then click option'

Acloudfunctions.callFunction

Bcloudfunctions.invokeFunction

Ccloudfunctions.call

Dcloudfunctions.execute

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect method names that do not exist.

The correct method to call a Cloud Function in Workflows is 'cloudfunctions.call'.

4fill in blank

hard

Fill both blanks to correctly handle a conditional step in the workflow.

GCP

steps:
  - checkStatus:
      switch:
        - condition: ${response.status_code == [1]
          next: successStep
        - condition: ${response.status_code == [2]
          next: failureStep

Drag options to blanks, or click blank then click option'

A200

B404

C500

D302

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing status codes or using non-standard codes.

Status code 200 means success, 404 means not found (failure).

5fill in blank

hard

Fill all three blanks to correctly define a loop that calls an API for each item.

GCP

steps:
  - processItems:
      for:
        value: item
        in: [1]
      steps:
        - callApi:
            call: http.post
            args:
              url: "https://api.example.com/data"
              body: $[2]
            result: apiResponse
      result: responses
  - returnResults:
      return: [3]

Drag options to blanks, or click blank then click option'

AitemsList

B{"item": item}

Cresponses

DdataArray

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable names or returning undefined variables.

The loop iterates over 'itemsList', sends each 'item' in the body, and returns 'responses'.

Practice

1. What is the main purpose of Google Cloud Workflows?

easy

A. To store large amounts of data securely

B. To automate and coordinate multiple cloud services in a sequence

C. To create virtual machines for computing

D. To monitor network traffic in real-time

Solution

1. Step 1: Understand the role of Workflows

   Workflows are designed to automate tasks by connecting different cloud services step-by-step.

2. Step 2: Compare options with this role

   Options B, C, and D describe storage, computing, and monitoring, which are not the main purpose of Workflows.

3. Final Answer:

   To automate and coordinate multiple cloud services in a sequence -> Option B

4. Quick Check:

   Workflows automate cloud tasks = A [OK]

Hint: Workflows connect services step-by-step to automate tasks [OK]

Common Mistakes:

• Confusing Workflows with storage or compute services
• Thinking Workflows monitor network traffic
• Assuming Workflows create virtual machines

2. Which of the following is the correct way to start a step in a Google Cloud Workflow YAML?

easy

A. steps:

B. start:

C. main:

D. execute:

Solution

1. Step 1: Recall the YAML structure for Workflows

   The main entry point for a workflow is defined under the main: key.

2. Step 2: Check other options

   Options like steps:, start:, and execute: are not valid top-level keys for starting a workflow.

3. Final Answer:

   main: -> Option C

4. Quick Check:

   Workflow starts with main: in YAML [OK]

Hint: Workflows start with main: block in YAML [OK]

Common Mistakes:

• Using steps: instead of main:
• Confusing start: as the entry point
• Trying execute: which is invalid

3. Given this snippet of a workflow YAML:

main:
  steps:
  - call: http.get
    args:
      url: "https://example.com/api"
  - return: ${steps[0].body.status}

What will the workflow return if the HTTP GET response body is {"status": "success"}?

medium

A. "success"

B. {"status": "success"}

C. An error because of wrong syntax

D. null

Solution

1. Step 1: Understand the call and return steps

   The first step calls an HTTP GET and stores the response in steps[0]. The second step returns the status field from the response body.

2. Step 2: Extract the status value from the response

   The response body is {"status": "success"}, so steps[0].body.status is "success".

3. Final Answer:

   "success" -> Option A

4. Quick Check:

   Return status field from HTTP response = "success" [OK]

Hint: Return uses ${steps[index].body.field} to get JSON values [OK]

Common Mistakes:

• Returning the whole body instead of the status field
• Syntax errors in accessing steps array
• Assuming null if not parsed correctly

4. Identify the error in this workflow snippet:

main:
  steps:
  - call: http.get
    args:
      url: "https://example.com/api"
  - return: steps[0].body.status

medium

A. Missing quotes around the URL

B. Incorrect indentation of steps

C. http.get is not a valid call

D. Missing ${} around the expression in return

Solution

1. Step 1: Check expression syntax in return

   In Workflows YAML, expressions must be wrapped in ${} to be evaluated.

2. Step 2: Verify other parts

   Indentation is correct, http.get is valid, and URL is quoted properly.

3. Final Answer:

   Missing ${} around the expression in return -> Option D

4. Quick Check:

   Expressions need ${} to evaluate in return [OK]

Hint: Wrap expressions in ${} to evaluate in workflow YAML [OK]

Common Mistakes:

• Forgetting ${} around expressions
• Misaligning YAML indentation
• Assuming http.get is invalid
• Not quoting URLs

5. You want to create a workflow that calls two APIs in sequence, but only calls the second API if the first returns status "ok". Which workflow feature helps you implement this conditional logic?

hard

A. Using switch or if steps to check the first API's response

B. Using parallel steps to call both APIs at the same time

C. Using retry to repeat the first API call until status is ok

D. Using return to stop the workflow after the first call

Solution

1. Step 1: Understand conditional execution in workflows

   Workflows support switch or if steps to decide which steps run based on conditions.

2. Step 2: Match the requirement

   To call the second API only if the first returns "ok", use if or switch to check the first response before proceeding.

3. Final Answer:

   Using switch or if steps to check the first API's response -> Option A

4. Quick Check:

   Conditional steps use if/switch to control flow [OK]

Hint: Use if or switch to run steps conditionally in workflows [OK]

Common Mistakes:

• Using parallel steps which run both APIs simultaneously
• Using retry which repeats calls but doesn't conditionally run next
• Using return which ends workflow early