Cloud Scheduler for cron jobs in GCP - Mini Project: Build & Apply

Cloud Scheduler for cron jobs

📖 Scenario: You work for a company that needs to run a task every day at 9 AM to clean up old files in a storage bucket. You will use Google Cloud Scheduler to create a cron job that triggers a Cloud Function daily.

🎯 Goal: Create a Cloud Scheduler job with a cron schedule that triggers a Cloud Function every day at 9 AM.

📋 What You'll Learn

Create a Cloud Scheduler job resource with the exact name daily-cleanup-job.

Set the schedule to run every day at 9 AM using cron syntax.

Configure the job to use the HTTP target with the exact URI https://us-central1-your-project.cloudfunctions.net/cleanupFunction.

Set the HTTP method to POST.

💡 Why This Matters

🌍 Real World

Cloud Scheduler is used to automate tasks like backups, cleanups, and report generation by running jobs on a schedule.

💼 Career

Knowing how to configure Cloud Scheduler jobs is essential for cloud engineers and DevOps professionals managing automated workflows in Google Cloud.

1

Create the Cloud Scheduler job resource

Create a Cloud Scheduler job resource named daily-cleanup-job in YAML format with an empty schedule and target section.

GCP

# Define the Cloud Scheduler job resource named daily-cleanup-job
# Your code here

Hint

Start by defining the job with the name daily-cleanup-job. Leave schedule and httpTarget empty for now.

2

Add the cron schedule

Add the schedule to run every day at 9 AM using the cron expression 0 9 * * * under the spec section of the daily-cleanup-job resource.

GCP

apiVersion: scheduler.googleapis.com/v1beta1
kind: Job
metadata:
  name: daily-cleanup-job
spec:
  schedule: ""
  httpTarget: {}
# Add the cron schedule 0 9 * * * below

Hint

The cron expression 0 9 * * * means every day at 9 AM.

3

Configure the HTTP target URI and method

Set the httpTarget section with the exact URI https://us-central1-your-project.cloudfunctions.net/cleanupFunction and HTTP method POST inside the daily-cleanup-job resource.

GCP

apiVersion: scheduler.googleapis.com/v1beta1
kind: Job
metadata:
  name: daily-cleanup-job
spec:
  schedule: "0 9 * * *"
  httpTarget: {}
# Add httpTarget uri and httpMethod here

Hint

Use uri and httpMethod keys inside httpTarget.

4

Add the timezone configuration

Add the timeZone field with the value America/Los_Angeles under the spec section of the daily-cleanup-job resource to ensure the job runs at 9 AM in that timezone.

GCP

apiVersion: scheduler.googleapis.com/v1beta1
kind: Job
metadata:
  name: daily-cleanup-job
spec:
  schedule: "0 9 * * *"
  httpTarget:
    uri: https://us-central1-your-project.cloudfunctions.net/cleanupFunction
    httpMethod: POST
# Add timeZone: America/Los_Angeles below

Hint

Adding timeZone ensures the job triggers at the correct local time.

Practice

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

easy

A. To store large amounts of data

B. To create virtual machines

C. To run tasks automatically at scheduled times

D. To monitor network traffic

Solution

1. Step 1: Understand Cloud Scheduler's role

   Cloud Scheduler is designed to run jobs automatically based on a schedule you set.

2. Step 2: Compare options with this role

   The incorrect options describe storing large amounts of data, creating virtual machines, and monitoring network traffic, which are other GCP services.

3. Final Answer:

   To run tasks automatically at scheduled times -> Option C

4. Quick Check:

   Cloud Scheduler = automatic task runner [OK]

Hint: Cloud Scheduler runs jobs on a timer, like an alarm clock [OK]

Common Mistakes:

• Confusing with storage or VM services
• Thinking it monitors traffic
• Assuming it manages databases

2. Which of the following is the correct format for a cron schedule in Cloud Scheduler?

easy

A. day month year hour minute

B. year month day hour minute

C. hour minute second day month

D. minute hour day month day-of-week

Solution

1. Step 1: Recall cron format used by Cloud Scheduler

   Cloud Scheduler uses the standard cron format: minute, hour, day of month, month, day of week.

2. Step 2: Match options to this format

   minute hour day month day-of-week matches this order exactly; others have incorrect sequences or extra fields.

3. Final Answer:

   minute hour day month day-of-week -> Option D

4. Quick Check:

   Cron format = minute hour day month day-of-week [OK]

Hint: Cron starts with minute, then hour, then day [OK]

Common Mistakes:

• Mixing up order of fields
• Including year field incorrectly
• Confusing day and month positions

3. Given this cron expression in Cloud Scheduler: 0 9 * * 1, when will the job run?

medium

A. Every Monday at 9:00 AM

B. Every day at 9:00 AM

C. Every hour on the first day of the month

D. Every Monday at 12:00 AM

Solution

1. Step 1: Decode the cron expression

   The expression means: minute=0, hour=9, day=any, month=any, day-of-week=1 (Monday).

2. Step 2: Interpret the schedule

   This runs the job every Monday at 9:00 AM.

3. Final Answer:

   Every Monday at 9:00 AM -> Option A

4. Quick Check:

   0 9 * * 1 = Monday 9 AM [OK]

Hint: Day-of-week 1 means Monday in cron [OK]

Common Mistakes:

• Thinking it runs daily
• Confusing day-of-week with day-of-month
• Mixing up hour and minute fields

4. You created a Cloud Scheduler job with cron expression 60 12 * * *. What is the issue?

medium

A. Minute value 60 is invalid; must be 0-59

B. Hour value 12 is invalid; must be 0-11

C. Day of month cannot be *

D. Cron expression is correct and will run daily at 12:00

Solution

1. Step 1: Check minute field validity

   The minute field must be between 0 and 59. 60 is invalid.

2. Step 2: Verify other fields

   Hour 12 is valid (represents noon), and day/month/day-of-week as * means every day.

3. Final Answer:

   Minute value 60 is invalid; must be 0-59 -> Option A

4. Quick Check:

   Minute must be 0-59, 60 is invalid [OK]

Hint: Minutes max at 59, 60 causes error [OK]

Common Mistakes:

• Using 60 for minutes
• Thinking hour 12 is invalid
• Assuming * is not allowed for day

5. You want a Cloud Scheduler job to run every weekday at 7:30 AM and trigger a Cloud Function via HTTP. Which cron expression and target setup is correct?

hard

A. Cron: 7 30 * * 1-5, Target: Pub/Sub topic

B. Cron: 30 7 * * 1-5, Target: HTTP with Cloud Function URL

C. Cron: 30 7 * * 0,6, Target: HTTP with Cloud Function URL

D. Cron: 30 7 * * *, Target: Cloud Storage bucket

Solution

1. Step 1: Choose correct cron expression for weekdays at 7:30 AM

   The expression 30 7 * * 1-5 means minute 30, hour 7, any day/month, weekdays (Monday=1 to Friday=5).

2. Step 2: Select proper target for Cloud Function trigger

   Cloud Scheduler triggers Cloud Functions via HTTP target using the function's URL.

3. Final Answer:

   Cron: 30 7 * * 1-5, Target: HTTP with Cloud Function URL -> Option B

4. Quick Check:

   Weekdays 7:30 AM + HTTP trigger = Cron: 30 7 * * 1-5, Target: HTTP with Cloud Function URL [OK]

Hint: Weekdays are 1-5 in cron; Cloud Functions use HTTP triggers [OK]

Common Mistakes:

• Swapping hour and minute
• Using weekend days instead of weekdays
• Wrong target type for Cloud Function