What Is Amazon EKS? Kubernetes on AWS Explained
Kubernetes is like a city traffic police for thousands of containers. Amazon EKS gives you a managed control plane so you do not run etcd and API servers yourself. It is powerful — and heavier than ECS for most student labs.
What you'll learn in this chapter
- Why Kubernetes exists
- What EKS manages vs what you manage
- EKS vs ECS vs self-managed k8s
- Cost warnings — control plane is not free
- When to choose EKS
1. Everyday example
Why do we need this?
Instagram-scale teams run hundreds of microservices. They want one API (kubectl) to deploy, scale and heal pods across clouds and on-prem. That API is Kubernetes.
What is it?
Amazon EKS (Elastic Kubernetes Service) runs the Kubernetes control plane for you (API server, etcd, scheduler). You add worker nodes (EC2 or Fargate) where pods run.
2. Control plane vs data plane
| Piece | Who runs it on EKS | Notes |
|---|---|---|
| API server, etcd, scheduler | AWS (multi-AZ) | You pay a flat control-plane hourly fee |
| Worker nodes | You — managed node group, self-managed, or Fargate | Where CPU/memory of pods is billed |
| Add-ons (CNI, CoreDNS, kube-proxy) | AWS add-ons or your charts | Keep versions compatible |
3. EKS vs ECS vs DIY Kubernetes
- ECS: simpler AWS-native model (services/tasks). Best default on AWS if you are not already a k8s shop.
- EKS: full k8s API, Helm, operators, multi-cloud skills. More moving parts.
- DIY k8s on EC2: you own etcd backups and upgrades — rarely worth it.
Ravindra Bagale's Tip
Do not start EKS “because LinkedIn says Kubernetes”. Start with ECS/Fargate unless your job or multi-cloud plan needs kubectl.
4. Cost warnings
Money
EKS control plane has an hourly charge per cluster even with zero pods. Worker nodes and Load Balancers add more. Delete lab clusters the same day. Prefer ECS Fargate for cheap Docker labs.
5. Interview angles
Q. What does EKS manage?
The Kubernetes control plane.
Q. Where do pods run?
On worker nodes (EC2) or EKS Fargate.
Q. EKS vs ECS?
EKS = Kubernetes API; ECS = AWS tasks/services.
Q. IRSA?
IAM Roles for Service Accounts — pods get IAM without node keys.
Q. Why not DIY control plane?
HA etcd and upgrades are hard; EKS does that.
Try at home
- Compare price of 1 EKS cluster idle vs 1 Fargate nginx task for 2 hours.
- Read AWS docs on EKS managed node groups (no need to create yet).
In short
- EKS = managed Kubernetes control plane on AWS.
- You still run or pay for workers.
- Heavier than ECS; powerful when you need k8s.
- Delete idle clusters — control plane is billed.
Practice Tasks
Nairobi Ride is a transport business in Nairobi. Wanjiru Kamau looks after its IT and cloud work. They count money in KES and run their AWS resources in the af-south-1 Region. In the tasks below you do real jobs for them using what this lesson teaches. All names, account IDs, IP addresses and numbers are made up for practice.
0 / 10
Easy Describe an EKS cluster
Why: Check the version, status and endpoint of the cluster.
What to do: Describe cluster nairobiride-eks.
- Read the task and decide which AWS service it is about.
- Write aws, then the service name, then the operation (the action word).
- Add each needed flag (--name) followed by its value from the task.
- Flags can be in any order. Click Check answer.
Easy How many addresses in a /16?
Why: Picking a VPC size needs this count.
What to do: Nairobi Ride plans the VPC 10.205.0.0/16. How many IP addresses does it hold in total?
- Write down the numbers the task gives you.
- Work it out step by step on paper.
- Type only the final answer in the box.
- Click Check answer.
Easy Port for SSH
Why: Security group rules need the right port.
What to do: Which TCP port must the security group open for SSH?
- Write down the numbers the task gives you.
- Work it out step by step on paper.
- Type only the final answer in the box.
- Click Check answer.
Easy Show where you are
Why: Before you copy or delete anything, you must know which folder you are in.
What to do: Wanjiru Kamau logged in to the Nairobi Ride server and is not sure which folder the terminal is in. Print the current folder path.
- Find the Linux command that does this job.
- Add the options (like -r or -h) the task needs.
- Add the file names, folders or users in the right order.
- Use sudo if the job changes system files or users. Click Check answer.
Medium Kubernetes Deployment
Why: A Deployment keeps the right number of pods running.
What to do: Write a Deployment named nairobiride-web with 3 replicas running image nginx:1.27.
- Start from the top-level keys the task names.
- Indent child keys with 2 spaces (no tabs).
- Fill in each property with the value from the task.
- Click Check answer. Key order does not matter.
Medium Connect kubectl to EKS
Why: update-kubeconfig writes the cluster details so kubectl can talk to it.
What to do: Update your kubeconfig for cluster nairobiride-eks in af-south-1.
- Read the task and decide which AWS service it is about.
- Write aws, then the service name, then the operation (the action word).
- Add each needed flag (--name) followed by its value from the task.
- Flags can be in any order. Click Check answer.
Medium Kubernetes LoadBalancer Service
Why: A Service of type LoadBalancer gets an AWS load balancer.
What to do: Write a Service of type LoadBalancer selecting app: web, port 80 to targetPort 8080.
- Start from the top-level keys the task names.
- Indent child keys with 2 spaces (no tabs).
- Fill in each property with the value from the task.
- Click Check answer. Key order does not matter.
Medium Usable IPs in an AWS /24 subnet
Why: AWS keeps 5 addresses in every subnet.
What to do: How many addresses can Nairobi Ride use for servers in subnet 10.205.1.0/24 on AWS?
- Write down the numbers the task gives you.
- Work it out step by step on paper.
- Type only the final answer in the box.
- Click Check answer.
Hard Create an EKS cluster
Why: The control plane needs a role and subnets to place its network interfaces.
What to do: Create cluster nairobiride-eks with role arn:aws:iam::104591109902:role/eksClusterRole and subnets subnet-0045d110dd02bb1,subnet-045d110dd02bb2.
- Read the task and decide which AWS service it is about.
- Write aws, then the service name, then the operation (the action word).
- Add each needed flag (--name) followed by its value from the task.
- Flags can be in any order. Click Check answer.
Hard Add a managed node group
Why: Node groups are the EC2 servers that run your pods.
What to do: Create node group ng-1 in cluster nairobiride-eks with role arn:aws:iam::104591109902:role/eksNodeRole, subnets subnet-0045d110dd02bb1 subnet-045d110dd02bb2, scaling minSize=1,maxSize=3,desiredSize=2.
- Read the task and decide which AWS service it is about.
- Write aws, then the service name, then the operation (the action word).
- Add each needed flag (--name) followed by its value from the task.
- Flags can be in any order. Click Check answer.
Revision, comparison and interview cards
Revise this lesson in a few minutes. Save the cards on your phone or download them as PNG files. The QR code on each card opens this lesson.
More cards: Ravi Sir's Cards.