How to use the command 'eksctl' (with examples)

eksctl is a powerful command-line interface (CLI) tool designed for Amazon Elastic Kubernetes Service (EKS). It simplifies the management of EKS clusters, making tasks like creation, management, and deletion of clusters straightforward and efficient. By providing a host of options and configurations, eksctl streamlines the process of handling complex Kubernetes setups, offering flexibility and ease of use for both seasoned operators and new users.

Use case 1: Create a basic cluster

Code:

eksctl create cluster

Motivation:
Creating a basic cluster with default configurations is often the first step for many users who want to quickly start experimenting with Kubernetes on AWS. This command provides a simple and fast way to set up an EKS cluster without diving into detailed configurations. It’s particularly useful for beginners who want to test out the EKS setup process or for anyone needing a quick deployment for development and testing purposes.

Explanation:
The command eksctl create cluster initiates the creation of an EKS cluster using default parameters. The tool automatically provisions the necessary infrastructure like the VPC, subnets, and worker nodes, and establishes all the requisite networking settings. This default setup assumes standard resource requirements and configurations which are suitable for general usage.

Example Output:

[ℹ]  eksctl version 0.50.0
[ℹ]  using region us-west-2
[ℹ]  setting availability zones to [us-west-2a us-west-2b us-west-2c]
[ℹ]  subnets for us-west-2a - public:192.168.0.0/19 private:192.168.64.0/19
...
[ℹ]  creating EKS cluster "kind-cluster" in "us-west-2" region
[✔]  all EKS cluster resource creation has been submitted

Use case 2: List the details about a cluster or all of the clusters

Code:

eksctl get cluster --name=name --region=region

Motivation:
Once a cluster is created or when managing multiple clusters, users often need to retrieve detailed information about them. Being able to list and inspect clusters helps in understanding their configuration and current status, which is essential for ensuring that resources are being utilized efficiently and to troubleshoot any issues.

Explanation:
In this command eksctl get cluster, the --name parameter specifies the name of the cluster whose details you want to retrieve. The --region parameter specifies the AWS region where the cluster is hosted. This command outputs visibility into existing clusters, providing critical insights regarding configurations and statuses.

Example Output:

NAME		REGION		EKSCTL CREATED
example-cluster	us-west-2	True

Use case 3: Create a cluster passing all configuration information in a file

Code:

eksctl create cluster --config-file=path/to/file

Motivation:
Creating a cluster with a configuration file allows for a more controlled and repeatable setup. This is particularly critical in production environments or when specific, custom configurations are needed. Having a configuration file ensures all necessary parameters are included, reduces human error, and improves automation processes.

Explanation:
The command eksctl create cluster along with the --config-file parameter allows users to define complex configurations in a file, which is then passed to the command for cluster creation. The configuration file includes specifications such as node types, sizes, scaling policies, and networking details.

Example Output:

[ℹ]  eksctl version 0.50.0
[ℹ]  using region us-west-2
[ℹ]  creating EKS cluster "custom-cluster" in "us-west-2" region
[✔]  all EKS cluster resource creation has been completed

Use case 4: Create a cluster using a configuration file and skip creating nodegroups until later

Code:

eksctl create cluster --config-file=<path> --without-nodegroup

Motivation:
In scenarios where you want to separately manage the infrastructure of the cluster and the compute resources (nodegroups), skipping the creation of nodegroups during initial setup makes sense. This approach is especially useful for custom cluster configurations or when nodegroups need to be provisioned differently than standard setups.

Explanation:
The --without-nodegroup option, used alongside --config-file, ensures that the initial creation of the cluster does not include nodegroups. This provides flexibility to add them at a later time as per specific requirements or conditions.

Example Output:

[ℹ]  eksctl version 0.50.0
[ℹ]  using region us-west-2
[ℹ]  creating EKS cluster "partial-cluster" in "us-west-2" region without nodegroups
[✔]  EKS control plane "partial-cluster" created

Use case 5: Delete a cluster

Code:

eksctl delete cluster --name=name --region=region

Motivation:
Over time, clusters may no longer be needed, needing cleanup or decommissioning to free up resources and reduce costs. The ability to delete clusters efficiently is crucial for maintaining a clean cloud environment and ensuring you are not incurring charges for unused resources.

Explanation:
The command eksctl delete cluster calls for the deletion of a specified cluster. --name identifies the cluster by name, and --region specifies its geographical location in AWS. This deletes not only the EKS cluster itself but also any associated AWS infrastructure set up by eksctl.

Example Output:

[ℹ]  using region us-west-2
[ℹ]  deleting EKS cluster "old-cluster"
[✔]  all cluster resources have been deleted

Use case 6: Create cluster and write cluster credentials to a file other than the default

Code:

eksctl create cluster --name=name --nodes=4 --kubeconfig=path/to/config.yaml

Motivation:
Advanced users, or specific scenarios, may require separating credentials for different clusters or projects. Writing cluster credentials to a non-default kubeconfig file helps in better organizing access configurations, especially when managing multiple clusters from a single workstation.

Explanation:
In this command, --name specifies the name of the cluster, and --nodes denotes the number of nodes needed. The --kubeconfig specifies the custom path where the kubeconfig file will be written, ensuring easy, organized access to the cluster’s API.

Example Output:

[ℹ]  creating EKS cluster "configured-cluster" in "us-west-2" region with 4 nodes
[✔]  saved kubeconfig as "path/to/config.yaml"

Use case 7: Create a cluster and prevent storing cluster credentials locally

Code:

eksctl create cluster --name=name --nodes=4 --write-kubeconfig=false

Motivation:
Security-conscious users or automated systems might prefer not to store access credentials locally to prevent unauthorized access. This setup is applicable in environments where strict access controls are necessary, or where alternate methods to access clusters are implemented.

Explanation:
--write-kubeconfig=false is an option used with eksctl create cluster which prevents the command from storing cluster credentials in a kubeconfig file on the local machine. This ensures that the cluster configuration remains secure and untouched on local storage.

Example Output:

[ℹ]  creating EKS cluster "secure-cluster" in "us-west-2" region with 4 nodes
[✔]  skipped saving kubeconfig

Use case 8: Create a cluster and let eksctl manage cluster credentials under the ~/.kube/eksctl/clusters directory

Code:

eksctl create cluster --name=name --nodes=4 --auto-kubeconfig

Motivation:
For users who prefer their credentials to be automatically managed and uniformly stored under a specific directory, letting eksctl handle storage simplifies their interaction with the kubeconfig files. It aims at centralized management of configuration credentials directly by eksctl.

Explanation:
When --auto-kubeconfig is used, eksctl automatically organizes and saves the kubeconfig files under the specified directory. This facilitates easy access and ensures that all cluster credentials managed by eksctl are in a consistent and accessible location.

Example Output:

[ℹ]  creating EKS cluster "managed-cluster" in "us-west-2" region with 4 nodes
[✔]  kubeconfig file has been written to "~/.kube/eksctl/clusters"

Conclusion:

eksctl offers comprehensive functionality for managing Amazon EKS clusters through various configurations and operations. Whether you’re simply creating a cluster or handling intricate setups with custom configurations, eksctl provides the tools needed for effective cluster management. Its flexibility, coupled with an intuitive command-line experience, makes it an indispensable tool for users navigating the intricacies of Kubernetes on AWS.