Desired replicas vs actual replicas in Kubernetes - Hands-On Comparison

Desired replicas vs actual replicas

📖 Scenario: You are managing a Kubernetes deployment for a web application. You want to check if the number of running pods matches the desired number of replicas specified in the deployment configuration.

🎯 Goal: Build a simple script that stores the desired number of replicas and the actual number of running pods, compares them, and prints whether the deployment is healthy or not.

📋 What You'll Learn

Create a variable desired_replicas with the exact value 3

Create a variable actual_replicas with the exact value 2

Write a comparison to check if desired_replicas equals actual_replicas

Print "Deployment is healthy" if they match, otherwise print "Deployment is not healthy"

💡 Why This Matters

🌍 Real World

Kubernetes operators and DevOps engineers often need to verify if the actual running pods match the desired replicas to ensure application availability.

💼 Career

Understanding how to compare desired and actual states is fundamental for monitoring and troubleshooting Kubernetes deployments in real jobs.

1

Set desired replicas

Create a variable called desired_replicas and set it to the integer 3.

Kubernetes

# Create a variable called desired_replicas and set it to 3
# Your code here

Need a hint?

Use the assignment operator = to set desired_replicas to 3.

2

Set actual replicas

Create a variable called actual_replicas and set it to the integer 2.

Kubernetes

desired_replicas = 3
# Create a variable called actual_replicas and set it to 2
# Your code here

Need a hint?

Use the assignment operator = to set actual_replicas to 2.

3

Compare desired and actual replicas

Write an if statement that compares desired_replicas and actual_replicas using ==.

Kubernetes

desired_replicas = 3
actual_replicas = 2
# Write an if statement comparing desired_replicas and actual_replicas
# Your code here

Need a hint?

Use if desired_replicas == actual_replicas: to check equality and assign the status variable accordingly.

4

Print deployment status

Write a print statement to display the value of the variable status.

Kubernetes

desired_replicas = 3
actual_replicas = 2
if desired_replicas == actual_replicas:
    status = "Deployment is healthy"
else:
    status = "Deployment is not healthy"
# Print the status variable
# Your code here

Need a hint?

Use print(status) to show the deployment health message.