Deployment Guide for CLO835 Assignment 2

This README provides step-by-step instructions to deploy your two-tier web application (MySQL + web) on a local Kind Kubernetes cluster running on an Amazon Linux EC2 instance. It also covers building and pushing Docker images to ECR, creating namespaces, ConfigMap, pull-secrets, applying manifests, and testing.

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Prerequisites

• AWS CLI configured with appropriate credentials
• kubectl, kind, docker, git installed on your EC2 instance
• IAM Role on EC2 with ECR permissions: ecr:GetAuthorizationToken, ecr:BatchGetImage, ecr:GetDownloadUrlForLayer
• Security Group: allow ports 22 (SSH) and 80 (HTTP)

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0. Install Prerequisites (Docker, Git, kubectl, kind)

# Update and install Docker & Git
sudo yum update -y
sudo yum install -y docker git

# Add ec2-user to docker group
sudo usermod -aG docker ec2-user

# Start Docker
echo "Starting Docker..."
sudo systemctl enable --now docker

# Install kubectl
curl -Lo kubectl https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl
chmod +x kubectl && sudo mv kubectl /usr/local/bin/

# Install Kind
curl -Lo kind "https://kind.sigs.k8s.io/dl/v0.20.0/kind-linux-amd64"
chmod +x kind && sudo mv kind /usr/local/bin/

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1. Create Kind Cluster

kind create cluster --name clo835 --config kind-config.yaml

Ensure your kind-config.yaml has:

kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
  extraPortMappings:
    - containerPort: 30000
      hostPort: 80
      protocol: TCP

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2. Create Namespaces

kubectl apply -f k8s/namespaces/ns.yaml

This creates two namespaces:

• mysql
• web

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3. Deploy ConfigMap (Application Configuration)

kubectl apply -f k8s/configmap/app-config.yaml

The ConfigMap stores available UI colors and the current selection:

apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
  namespace: web
data:
  availableColors: "blue,green,red"
  currentColor: "green"

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4. Create ECR Pull-Secrets

Authenticate to ECR and create a Kubernetes secret in both namespaces so Pods can pull private images.

# For mysql namespace
kubectl create secret docker-registry ecr-pull-secret \
  --docker-server=164340264957.dkr.ecr.us-east-1.amazonaws.com \
  --docker-username=AWS \
  --docker-password="$(aws ecr get-login-password --region us-east-1)" \
  --docker-email=you@example.com \
  -n mysql

# For web namespace
kubectl create secret docker-registry ecr-pull-secret \
  --docker-server=164340264957.dkr.ecr.us-east-1.amazonaws.com \
  --docker-username=AWS \
  --docker-password="$(aws ecr get-login-password --region us-east-1)" \
  --docker-email=you@example.com \
  -n web

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5. Apply Kubernetes Manifests

Note: Pods and ReplicaSets are optional if using Deployments only.

# (Optional) Pods
kubectl apply -f k8s/pods/

# (Optional) ReplicaSets
kubectl apply -f k8s/replicasets/

# Deployments
kubectl apply -f k8s/deployments/

# Services
kubectl apply -f k8s/services/

This will create:

• Deployments for MySQL and web (3 replicas each, rolling update strategy)
• ClusterIP Service for MySQL
• NodePort Service (port 30000) for web, exposed on VM port 80 via Kind mapping

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6. Verify Deployment

kubectl get ns
kubectl get pods -n mysql
kubectl get pods -n web
kubectl get rs -n mysql -n web
kubectl get deploy -n mysql -n web
kubectl get svc -n mysql -n web

Check Logs and Connectivity

# Logs from a web Pod
kubectl logs -n web <web-pod-name>

# Inside a web Pod
kubectl exec -n web <web-pod-name> -- curl -s localhost:8080

# From VM or laptop (HTTP on port 80)
curl http://<EC2_PUBLIC_IP>/

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7. Change UI Color

To switch the theme color dynamically, patch the ConfigMap and roll out the update:

kubectl patch configmap app-config -n web \
  --type merge \
  -p '{"data":{"currentColor":"red"}}'

kubectl rollout restart deployment/web-deployment -n web
kubectl rollout status deployment/web-deployment -n web

All three web replicas will restart one-by-one and pick up the new APP_COLOR value.

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References

• Kind: https://kind.sigs.k8s.io/
• Kubernetes Documentation: https://kubernetes.io/docs/
• AWS ECR: https://docs.aws.amazon.com/AmazonECR/latest/userguide/using-authorization-token.html

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End of README