Kubernetes Deployment Lifecycle — EKS on LocalStack

A self-contained demo that makes all 7 steps of the Kubernetes Deployment Lifecycle visible in real time, using a locally emulated EKS cluster powered by LocalStack.

kubectl apply
     │
     ▼
┌─────────────┐   ┌──────────────────┐   ┌───────────┐   ┌─────────┐
│  API Server │──▶│ Controller Mgr   │──▶│ Scheduler │──▶│ Kubelet │
│  (etcd)     │   │ Deployment+RS    │   │ Node pick │   │ + CRI   │
└─────────────┘   └──────────────────┘   └───────────┘   └─────────┘
                                                               │
                                                               ▼
                                                    ┌──────────────────┐
                                                    │ Pending→Running  │
                                                    │ Readiness probe  │
                                                    │ → Ready+Endpoint │
                                                    └──────────────────┘

---

What's in this repo

k8s-lifecycle-demo/
├── app/
│   ├── app.py            # Flask counter service (GET /, GET /health)
│   ├── requirements.txt
│   └── Dockerfile
├── k8s/
│   └── deployment.yaml   # Namespace + Deployment (2 replicas) + NodePort Service
├── docker-compose.yml    # LocalStack Pro container
├── setup.sh              # One-time cluster setup (run before the talk)
├── demo.sh               # 7-step live demo script
└── README.md

---

Prerequisites

Tool	Version	Install
Docker Desktop	≥ 4.x	https://docs.docker.com/get-docker/
kubectl	≥ 1.28	https://kubernetes.io/docs/tasks/tools/
AWS CLI v2	≥ 2.x	https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html
awslocal	latest	pip install awscli-local
LocalStack CLI	latest	pip install localstack
k3d	≥ 5.x	https://k3d.io/#installation
Python 3.11+	(for the app build)	https://python.org

LocalStack Pro is required for EKS emulation. Get a free trial auth token at https://localstack.cloud.

---

Quick start

1. Set your LocalStack auth token

export LOCALSTACK_AUTH_TOKEN=<your-token>

Add it to your shell profile so it persists across sessions.

2. Run setup

chmod +x setup.sh demo.sh
./setup.sh

setup.sh will:

1. Start LocalStack via Docker Compose
2. Create an EKS cluster called lifecycle-demo
3. Configure kubectl to point at it
4. Build the counter-app:latest Docker image
5. Load the image into the cluster nodes (via k3d)

3. Run the demo

./demo.sh

Press ENTER to advance between each step.

For a fully-automatic run (e.g. recording):

AUTO=1 STEP_DELAY=6 ./demo.sh

---

The 7 steps

#	Component	What you'll see
1	API Server	kubectl apply → HTTP 201, object stored in etcd
2	Controller Manager	Deployment + ReplicaSet reconciliation, Pod objects appear
3	Scheduler	Pods assigned to nodes; `kubectl describe pod
4	Kubelet	Image pull events, container start events
5	Pod phase	kubectl get pods -w → Pending → Running
6	Readiness probe	Running → Ready; Service Endpoints populated
7	Self-healing	Pod deleted → replacement races through lifecycle again

---

The app

The counter service exposes two endpoints:

GET /       → {"hits": 42, "pod": "counter-app-xxx", "node": "k3d-..."}
GET /health → {"status": "ok", "pod": "counter-app-xxx"}

Because each replica keeps its own in-memory counter, repeated curl calls to the NodePort will hit different pods — making pod identity and load balancing visible to the audience.

# NodePort is 30080 on each node
NODE_IP=$(kubectl get nodes -o jsonpath='{.items[0].status.addresses[?(@.type=="InternalIP")].address}')
curl http://${NODE_IP}:30080/

---

Customisation

Variable	Default	Purpose
CLUSTER_NAME	lifecycle-demo	EKS / k3d cluster name
AWS_DEFAULT_REGION	us-east-1	LocalStack region
AUTO	0	1 = skip ENTER prompts
STEP_DELAY	4	Seconds to pause in AUTO mode

Pass them as environment variables:

CLUSTER_NAME=my-cluster AUTO=1 ./demo.sh

---

Cleanup

# Remove demo namespace
kubectl delete namespace demo

# Tear down the whole cluster
awslocal eks delete-cluster --name lifecycle-demo

# Stop LocalStack
docker compose down -v

---

Troubleshooting

Pods stay in Pending The image wasn't loaded into the cluster nodes. Re-run ./setup.sh or manually:

k3d image import counter-app:latest --cluster lifecycle-demo

imagePullBackOff Same cause. The manifest uses imagePullPolicy: Never — the image must be pre-loaded; it will never be pulled from a registry.

kubectl shows the wrong cluster

kubectl config use-context lifecycle-demo

LocalStack EKS not available EKS is a Pro feature. Confirm your LOCALSTACK_AUTH_TOKEN is set and that the container started cleanly:

docker logs localstack | grep -i eks

k3d not found setup.sh falls back to docker exec + ctr images import. Install k3d for a smoother experience: https://k3d.io/#installation