Creating Deployments with YAML in Kubernetes - Try It Yourself

Creating Deployments with YAML

📖 Scenario: You are working as a DevOps engineer. Your team needs to deploy a simple web application on Kubernetes. You will create a Deployment YAML file step-by-step to manage the application pods.

🎯 Goal: Build a Kubernetes Deployment YAML file that defines a Deployment named webapp-deployment running 3 replicas of the nginx:1.21 container.

📋 What You'll Learn

Create a Deployment YAML with apiVersion, kind, and metadata

Add a spec section with replicas and selector

Define the pod template with container name and image

Output the complete YAML content

💡 Why This Matters

🌍 Real World

Kubernetes Deployments are used to manage and scale containerized applications in production environments.

💼 Career

Understanding how to write Deployment YAML files is essential for DevOps engineers and site reliability engineers working with Kubernetes.

1

Create the Deployment header and metadata

Create a YAML file starting with apiVersion: apps/v1, kind: Deployment, and metadata with name: webapp-deployment.

Kubernetes

# Your code here

Need a hint?

Start by specifying the API version, the kind of resource, and the deployment name under metadata.

2

Add replicas and selector to the spec

Add a spec section with replicas: 3 and a selector matching app: webapp under matchLabels.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp-deployment
# Add spec with replicas and selector below
# Your code here

Need a hint?

The spec defines how many pods to run and how to select them using labels.

3

Define the pod template with container details

Under spec.template, add metadata.labels with app: webapp. Then add spec.containers with one container named nginx-container using the image nginx:1.21.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: webapp
# Add template with metadata.labels and containers below
# Your code here

Need a hint?

The pod template defines the pods that will be created. Labels must match the selector. Containers need a name and image.

4

Output the complete Deployment YAML

Print the entire YAML content stored in a variable called deployment_yaml.

Kubernetes

deployment_yaml = '''
apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: webapp
  template:
    metadata:
      labels:
        app: webapp
    spec:
      containers:
      - name: nginx-container
        image: nginx:1.21
'''
# Print the deployment_yaml variable below
# Your code here

Need a hint?

Use print(deployment_yaml) to show the full YAML content.