Progressive delivery concept in Kubernetes - Mini Project: Build & Apply

Progressive Delivery Concept with Kubernetes

📖 Scenario: You work as a DevOps engineer for a company that wants to safely release new versions of their web application. Instead of deploying the new version to all users at once, you will use progressive delivery to gradually roll out the update. This helps catch issues early and reduces risk.

🎯 Goal: Build a simple Kubernetes deployment manifest that uses labels and selectors to manage a canary release. You will create the initial deployment, add a canary version with a label, and then use a service selector to route traffic to both versions progressively.

📋 What You'll Learn

Create a Kubernetes deployment manifest for the stable version of the app

Add a canary deployment with a specific label

Create a service that selects both stable and canary pods using labels

Print the final combined manifest to verify the setup

💡 Why This Matters

🌍 Real World

Progressive delivery helps companies release new software versions safely by controlling how many users get the update at a time.

💼 Career

DevOps engineers use Kubernetes manifests with labels and services to manage canary deployments and reduce risk during software releases.

1

Create the stable deployment manifest

Create a Kubernetes deployment manifest named stable-deployment.yaml with these exact specifications: deployment name webapp-stable, app label webapp, container image nginx:1.21, and 3 replicas.

Kubernetes

# Create a deployment manifest for the stable version
# Your code here

Need a hint?

Use version: stable as a label to identify the stable pods.

2

Add the canary deployment manifest

Add a new deployment manifest named canary-deployment.yaml with deployment name webapp-canary, app label webapp, version label canary, container image nginx:1.22, and 1 replica.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp-stable
spec:
  replicas: 3
  selector:
    matchLabels:
      app: webapp
      version: stable
  template:
    metadata:
      labels:
        app: webapp
        version: stable
    spec:
      containers:
      - name: nginx
        image: nginx:1.21

# Add the canary deployment manifest below
# Your code here

Need a hint?

Use version: canary label to identify the canary pods.

3

Create a service selecting both stable and canary pods

Create a Kubernetes service manifest named webapp-service.yaml that selects pods with label app: webapp (both stable and canary). Use port 80 for the service and target port 80 for the container.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp-stable
spec:
  replicas: 3
  selector:
    matchLabels:
      app: webapp
      version: stable
  template:
    metadata:
      labels:
        app: webapp
        version: stable
    spec:
      containers:
      - name: nginx
        image: nginx:1.21
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp-canary
spec:
  replicas: 1
  selector:
    matchLabels:
      app: webapp
      version: canary
  template:
    metadata:
      labels:
        app: webapp
        version: canary
    spec:
      containers:
      - name: nginx
        image: nginx:1.22

# Add a service manifest selecting pods with label app: webapp
# Your code here

Need a hint?

The service selector should match app: webapp to include both stable and canary pods.

4

Print the combined manifest

Print the entire combined Kubernetes manifest containing the stable deployment, canary deployment, and service to verify the progressive delivery setup.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp-stable
spec:
  replicas: 3
  selector:
    matchLabels:
      app: webapp
      version: stable
  template:
    metadata:
      labels:
        app: webapp
        version: stable
    spec:
      containers:
      - name: nginx
        image: nginx:1.21
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp-canary
spec:
  replicas: 1
  selector:
    matchLabels:
      app: webapp
      version: canary
  template:
    metadata:
      labels:
        app: webapp
        version: canary
    spec:
      containers:
      - name: nginx
        image: nginx:1.22
---
apiVersion: v1
kind: Service
metadata:
  name: webapp-service
spec:
  selector:
    app: webapp
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80

# Print the full manifest below
# Your code here

Need a hint?

Use a print statement to output the full manifest string.