Pod Disruption Budgets in Kubernetes - Mini Project: Build & Apply

Pod Disruption Budgets

📖 Scenario: You manage a Kubernetes cluster running a web application. To keep the app reliable during maintenance, you want to control how many pods can be disrupted at once.

🎯 Goal: Create a Pod Disruption Budget (PDB) YAML manifest that limits disruptions to your app pods, ensuring at least one pod is always available during voluntary disruptions.

📋 What You'll Learn

Create a YAML manifest named pdb.yaml for a Pod Disruption Budget

Set minAvailable to 1 to keep at least one pod running

Target pods with the label app: webapp

Use the policy/v1 API version

Name the PDB webapp-pdb

💡 Why This Matters

🌍 Real World

Pod Disruption Budgets help maintain application availability during planned maintenance or upgrades by limiting how many pods can be taken down at once.

💼 Career

Understanding PDBs is essential for Kubernetes administrators and DevOps engineers to ensure high availability and reliability of applications in production environments.

1

Create the basic YAML structure for the Pod Disruption Budget

Create a YAML file named pdb.yaml with the following keys: apiVersion set to policy/v1, kind set to PodDisruptionBudget, and metadata with name set to webapp-pdb.

Kubernetes

# Your code here

Need a hint?

Start by defining the API version, kind, and metadata name exactly as specified.

2

Add the spec section with minAvailable

Add a spec section to pdb.yaml with minAvailable set to 1.

Kubernetes

apiVersion: policy/v1
kind: PodDisruptionBudget
metadata:
  name: webapp-pdb
# Add spec with minAvailable: 1 below
# Your code here

Need a hint?

Indent minAvailable under spec exactly with value 1.

3

Add the selector to target pods with label app: webapp

Under spec, add a selector with matchLabels targeting pods labeled app: webapp.

Kubernetes

apiVersion: policy/v1
kind: PodDisruptionBudget
metadata:
  name: webapp-pdb
spec:
  minAvailable: 1
  # Add selector with matchLabels: app: webapp below
  # Your code here

Need a hint?

Indent selector and matchLabels properly under spec.

4

Display the complete Pod Disruption Budget YAML

Print the contents of pdb.yaml to verify the Pod Disruption Budget manifest.

Kubernetes

# Print the contents of pdb.yaml
# Your code here

Need a hint?

Use cat pdb.yaml in your terminal to display the file content.