EKS cluster creation in AWS - Step-by-Step Execution

Process Flow - EKS cluster creation

Start: Define cluster config

↓

Create VPC and networking

↓

Create EKS cluster control plane

↓

Create worker nodes (EC2 or Fargate)

↓

Join nodes to cluster

↓

Cluster ready for workloads

↓

End

This flow shows the main steps to create an EKS cluster: define config, set up networking, create control plane, add worker nodes, then the cluster is ready.

Execution Sample

AWS

eksctl create cluster --name my-cluster --region us-west-2 --nodes 2

This command creates an EKS cluster named 'my-cluster' in the us-west-2 region with 2 worker nodes.

Process Table

Step	Action	Status	Details	Result
1	Parse command and config	Success	Cluster name=my-cluster, region=us-west-2, nodes=2	Ready to create resources
2	Create VPC and networking	Success	VPC with subnets and security groups created	Networking ready
3	Create EKS control plane	In Progress	Provisioning control plane in AWS	Control plane creating
4	Control plane active	Success	Control plane endpoint available	Control plane ready
5	Create worker nodes	In Progress	Launching 2 EC2 instances for nodes	Nodes provisioning
6	Nodes joined cluster	Success	Nodes registered and ready	Cluster nodes ready
7	Cluster creation complete	Success	Cluster is active and ready for workloads	EKS cluster ready

💡 Cluster creation completes when control plane and nodes are active and joined

Status Tracker

Variable	Start	After Step 2	After Step 4	After Step 6	Final
VPC	None	Created	Created	Created	Created
ControlPlaneStatus	None	None	Active	Active	Active
WorkerNodesCount	0	0	0	2	2
ClusterStatus	Not created	Not created	Not created	Active	Active

Key Moments - 2 Insights

Why does the cluster status remain 'Not created' until after worker nodes join?

The cluster is considered fully ready only after both the control plane is active and worker nodes have joined, as shown in execution_table rows 4 and 6.

What happens if the VPC creation fails at step 2?

Subsequent steps cannot proceed because networking is required for the control plane and nodes, so the process stops early as indicated by the status in execution_table row 2.

Visual Quiz - 3 Questions

Look at the execution table, at which step does the control plane become active?

A Step 3

B Step 5

C Step 4

D Step 6

💡 Hint

Check the 'ControlPlaneStatus' and 'Status' columns in execution_table row 4.

According to variable_tracker, how many worker nodes exist after step 6?

A 1

B 2

C 0

D Not defined

💡 Hint

Look at the 'WorkerNodesCount' row under 'After Step 6' in variable_tracker.

If the VPC creation failed, what would happen to the cluster creation process?

A It would stop before creating the control plane

B It would continue creating the control plane

C It would create worker nodes only

D It would complete successfully anyway

💡 Hint

Refer to key_moments explanation about step 2 failure and execution_table row 2.

Concept Snapshot

EKS cluster creation steps:
1. Define cluster config (name, region, nodes)
2. Create VPC and networking
3. Create EKS control plane
4. Launch worker nodes
5. Nodes join cluster
6. Cluster ready for workloads
Use 'eksctl create cluster' for simple setup.

Full Transcript

Creating an EKS cluster involves several steps. First, you define the cluster configuration such as name, region, and number of nodes. Then, the system creates the necessary networking components like VPC and subnets. Next, the EKS control plane is provisioned and becomes active. After that, worker nodes are launched and join the cluster. Once nodes are registered, the cluster is ready to run workloads. If any step like VPC creation fails, the process stops early. The command 'eksctl create cluster' automates these steps for you.

Practice

1.

What is the main purpose of creating an Amazon EKS cluster?

easy

A. To store large amounts of data in the cloud

B. To run Kubernetes applications without managing the underlying servers

C. To create virtual machines for running Windows applications

D. To manage user access and permissions in AWS

Solution

1. Step 1: Understand EKS cluster purpose

   Amazon EKS is a managed Kubernetes service that lets you run containerized applications without managing servers.

2. Step 2: Compare options

   Options A, B, and D describe other AWS services or functions unrelated to EKS clusters.

3. Final Answer:

   To run Kubernetes applications without managing the underlying servers -> Option B

4. Quick Check:

   EKS = Managed Kubernetes service [OK]

Hint: EKS runs Kubernetes without server management [OK]

Common Mistakes:

• Confusing EKS with EC2 virtual machines
• Thinking EKS is for data storage
• Mixing EKS with IAM user management

2.

Which of the following is the correct AWS CLI command to create an EKS cluster named my-cluster with role ARN arn:aws:iam::123456789012:role/EKSRole and subnets subnet-abc123 and subnet-def456?

easy

A. aws eks create-cluster --cluster-name my-cluster --role arn:aws:iam::123456789012:role/EKSRole --vpc-config subnets=subnet-abc123,subnet-def456

B. aws eks create-cluster --name my-cluster --role-arn arn:aws:iam::123456789012:role/EKSRole --resources-vpc-config subnetIds=subnet-abc123 subnet-def456

C. aws eks create-cluster --name my-cluster --role-arn arn:aws:iam::123456789012:role/EKSRole --resources-vpc-config subnetIds=subnet-abc123,subnet-def456

D. aws eks create-cluster --name my-cluster --role arn:aws:iam::123456789012:role/EKSRole --resources-vpc-config subnetIds=subnet-abc123,subnet-def456

Solution

1. Step 1: Check AWS CLI syntax for EKS cluster creation

   The correct command uses --name for cluster name, --role-arn for IAM role, and --resources-vpc-config subnetIds=... for subnet IDs separated by commas.

2. Step 2: Identify correct option

   aws eks create-cluster --name my-cluster --role-arn arn:aws:iam::123456789012:role/EKSRole --resources-vpc-config subnetIds=subnet-abc123,subnet-def456 matches the correct syntax exactly. Options A and D use incorrect flags (--cluster-name, --role). aws eks create-cluster --name my-cluster --role-arn arn:aws:iam::123456789012:role/EKSRole --resources-vpc-config subnetIds=subnet-abc123 subnet-def456 misses a comma between subnet IDs.

3. Final Answer:

   aws eks create-cluster --name my-cluster --role-arn arn:aws:iam::123456789012:role/EKSRole --resources-vpc-config subnetIds=subnet-abc123,subnet-def456 -> Option C

4. Quick Check:

   Correct CLI syntax = aws eks create-cluster --name my-cluster --role-arn arn:aws:iam::123456789012:role/EKSRole --resources-vpc-config subnetIds=subnet-abc123,subnet-def456 [OK]

Hint: Use --name, --role-arn, and comma-separated subnetIds [OK]

Common Mistakes:

• Using --role instead of --role-arn
• Missing commas between subnet IDs
• Using wrong flag names like --cluster-name

3.

Given this AWS CLI command to create an EKS cluster:

aws eks create-cluster --name test-cluster --role-arn arn:aws:iam::123456789012:role/EKSRole --resources-vpc-config subnetIds=subnet-11111111,subnet-22222222,securityGroupIds=sg-12345678

What will happen after running this command?

medium

A. The command will fail due to incorrect subnet ID format

B. The command will fail because security groups cannot be specified during cluster creation

C. The cluster will be created but only in one subnet ignoring the second subnet

D. The cluster test-cluster will be created using the specified subnets and security group

Solution

1. Step 1: Understand parameters in the command

   The command specifies cluster name, IAM role, subnet IDs, and security group IDs correctly using --resources-vpc-config.

2. Step 2: Check if security groups are allowed

   Security groups can be specified during cluster creation to control network access. The subnet IDs are comma-separated and valid format.

3. Final Answer:

   The cluster test-cluster will be created using the specified subnets and security group -> Option D

4. Quick Check:

   Valid subnet and security group syntax = The cluster test-cluster will be created using the specified subnets and security group [OK]

Hint: Security groups allowed in --resources-vpc-config [OK]

Common Mistakes:

• Thinking security groups can't be set at creation
• Assuming only one subnet is allowed
• Confusing subnet ID format with invalid syntax

4.

You tried to create an EKS cluster with this command:

aws eks create-cluster --name mycluster --role-arn arn:aws:iam::123456789012:role/EKSRole --resources-vpc-config subnetIds=subnet-12345 subnet-67890

The command failed. What is the most likely cause?

medium

A. Missing comma between subnet IDs in subnetIds parameter

B. Incorrect IAM role ARN format

C. Cluster name mycluster is invalid

D. Subnets are in different availability zones

Solution

1. Step 1: Review subnetIds parameter format

   The subnet IDs must be comma-separated inside the subnetIds= value. Here, a space separates them, which is invalid syntax.

2. Step 2: Check other parameters

   The IAM role ARN format looks correct, cluster name is valid, and subnets in different zones are recommended, not an error.

3. Final Answer:

   Missing comma between subnet IDs in subnetIds parameter -> Option A

4. Quick Check:

   Comma separates subnet IDs [OK]

Hint: Comma separate subnet IDs, not spaces [OK]

Common Mistakes:

• Using spaces instead of commas between subnet IDs
• Assuming cluster name rules cause failure
• Confusing subnet zones with errors

5.

You want to create a highly available EKS cluster. Which setup is best practice for the network configuration?

• Use a single subnet in one availability zone
• Use multiple subnets in different availability zones
• Use only public subnets
• Use subnets without any security groups

hard

A. Use multiple subnets in different availability zones

B. Use a single subnet in one availability zone

C. Use only public subnets

D. Use subnets without any security groups

Solution

1. Step 1: Understand high availability in EKS

   High availability means the cluster stays up even if one zone fails. Using multiple subnets in different availability zones achieves this.

2. Step 2: Evaluate other options

   Single subnet risks zone failure. Only public subnets expose resources unnecessarily. Subnets without security groups lack network protection.

3. Final Answer:

   Use multiple subnets in different availability zones -> Option A

4. Quick Check:

   Multi-AZ subnets = High availability [OK]

Hint: Spread subnets across zones for reliability [OK]

Common Mistakes:

• Using only one subnet risking downtime
• Exposing cluster on public subnets unnecessarily
• Ignoring security groups for network safety