AWS Kubernetes

AWS Kubernetes is a Kubernetes cluster deployed using Kubeadm tool. It provides full integration with AWS. It is able to handle ELB load balancers, EBS disks, Route53 domains and other AWS resources.

• Updates
• Prerequisites and dependencies
• Configuration
  • Using multiple / different subnets for workers nodes
• Creating AWS Kubernetes Cluster
• Deleting AWS Kubernetes Cluster
• Add-ons
• Custom Add-ons
• Tagging
• Frequently Asked Questions
  • How to access the Kubernetes Dashboard

Updates

• 1.4.2023 Update to Kubernetes 1.26.3 + update add-ons (Ingress-NGINX Controller, External DNS, Metrics Server, AWS EBS CSI Driver)
• 4.3.2023 Update to Kubernetes 1.26.2 + update add-ons (Ingress-NGINX Controller)
• 22.1.2023 Update to Kubernetes 1.26.1 + update add-ons (External DNS)
• 10.12.2022 Update to Kubernetes 1.26.0 + update add-ons (AWS EBS CSI Driver, Metrics server)
• 13.11.2022 Update to Kubernetes 1.25.4 + update add-ons
• 2.10.2022 Update to Kubernetes 1.25.2 + update add-ons
• 26.8.2022 Update to Kubernetes 1.25.0 + Calico upgrade
• 22.8.2022 Update to Kubernetes 1.24.4
• 16.7.2022 Update to Kubernetes 1.24.3
• 27.6.2022 Update to Kubernetes 1.24.2
• 11.6.2022 Update to Kubernetes 1.24.1 + update add-ons + remove dependency on the template provider
• 8.5.2022 Update to Kubernetes 1.24.0 + update add-ons
• 23.3.2022 Update to Kubernetes 1.23.5 + update add-ons
• 19.2.2022 Update to Kubernetes 1.23.4
• 12.2.2022 Update to Kubernetes 1.23.2
• 29.12.2021 Update to Kubernetes 1.23.1
• 11.12.2021 Update to Kubernetes 1.23.0

Prerequisites and dependencies

AWS Kubernetes deploys into an existing VPC / public subnet. If you don't have your VPC / subnet yet, you can use this configuration to create one. To deploy AWS Kubernetes there are no other dependencies apart from Terraform. Kubeadm is used only on the EC2 hosts and doesn't have to be installed locally.

Configuration

The configuration is done through Terraform variables. Example tfvars file is part of this repo and is named example.tfvars. Change the variables to match your environment / requirements before running terraform apply ....

Option	Explanation	Example
aws_region	AWS region which should be used	eu-central-1
cluster_name	Name of the Kubernetes cluster (also used to name different AWS resources)	my-aws-kubernetes
master_instance_type	AWS EC2 instance type for master	t2.medium
worker_instance_type	AWS EC2 instance type for worker	t2.medium
ssh_public_key	SSH key to connect to the remote machine	~/.ssh/id_rsa.pub
master_subnet_id	Subnet ID where master should run	subnet-8d3407e5
worker_subnet_ids	List of subnet IDs where workers should run	[ "subnet-8d3407e5" ]
min_worker_count	Minimal number of worker nodes	3
max_worker_count	Maximal number of worker nodes	6
hosted_zone	DNS zone which should be used	my-domain.com
hosted_zone_private	Is the DNS zone public or private	false
addons	List of add-ons which should be installed	[ "https://..." ]
tags	Tags which should be applied to all resources	see example.tfvars file
tags2	Tags in second format which should be applied to AS groups	see example.tfvars file
ssh_access_cidr	List of CIDRs from which SSH access is allowed	[ "0.0.0.0/0" ]
api_access_cidr	List of CIDRs from which API access is allowed	[ "0.0.0.0/0" ]

Using multiple / different subnets for workers nodes

In order to run workers in additional / different subnet(s) than master you have to tag the subnets with kubernetes.io/cluster/{cluster_name}=shared. For example kubernetes.io/cluster/my-aws-kubernetes=shared. During the cluster setup, the bootstrapping script will automatically add these tags to the subnets specified in worker_subnet_ids.

Creating AWS Kubernetes Cluster

To create AWS Kubernetes cluster,

• Export AWS credentials into environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY
• Apply Terraform configuration:

terraform apply --var-file example.tfvars

Deleting AWS Kubernetes Cluster

To delete AWS Kubernetes cluster,

• Export AWS credentials into environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY
• Destroy Terraform configuration:

terraform destroy --var-file example.tfvars

Add-ons

Currently, following add-ons are supported:

• Kubernetes dashboard
• Heapster for resource monitoring
• Storage class and CSI driver for automatic provisioning of persistent volumes
• External DNS (Replaces Route53 mapper)
• Ingress
• Autoscaler

The add-ons will be installed automatically based on the Terraform variables.

Custom Add-ons

Custom add-ons can be added if needed. For every URL in the addons list, the initialization scripts will automatically call kubectl -f apply <Addon URL> to deploy it. The cluster is using RBAC. So the custom add-ons have to be RBAC ready.

Tagging

If you need to tag resources created by your Kubernetes cluster (EBS volumes, ELB load balancers etc.) check this AWS Lambda function which can do the tagging.

## Frequently Asked Questions

How to access the Kubernetes Dashboard

The Kubernetes Dashboard add-on is by default not exposed to the internet. This is intentional for security reasons (no authentication / authorization) and to save costs for Amazon AWS ELB load balancer.

You can access the dashboard easily fro any computer with installed and configured kubectl:

1. From command line start kubectl proxy
2. Go to your browser and open http://127.0.0.1:8001/ui