EKS - Nahuel Hernandez

Karpenter Kubernetes Node Autoscaling

K8S Autoscaling helps us to scale out or in our applications. Pod-based scaling or HPA is an excellent first step. However, the problem is when we need more K8S nodes to contain our PODs. Karpenter is a Node-based scaling solution built for K8S, and its goal is to improve efficiency and cost. It is a great solution because we don't need to configure instances types or create nodegroups, which drastically simplifies configuration. On the other hand, the integration with Spot instances is painless and we can reduce our costs (up to 90% cheaper than On-Demand instances)

January 24, 2022

8-Minute Read

A Kubernetes node autoscaling solution is a tool that automatically adjusts the size of the Kubernetes cluster based on the demands of our workloads. Because of this, we don’t need to create manually a new Kubernetes Node every time we need it (or delete it). Karpenter automatically provisions new nodes in response to unschedulable pods. It does this by observing events within the Kubernetes cluster, and then sending commands to the underlying cloud provider. It is designed to work with…

Ingress Controller and External DNS with Route53 on EKS

One great way to expose Kubernetes Applications to the world is using Ingress resources. On EKS we can avoid creating one Load Balancer each time we expose an Application. Moreover, K8S Ingress offers a single entry point to the cluster. So we can save money, manage and monitor one Load Balancer and reduce the attack surface of the Cluster. This is great, however, every time we need to expose an application we will need to create and manage DNS records manually. We can set externalDNS by adding a simple annotation to our ingress resources pointing to the DNS record and then it will be created automatically on Route53. In conclusion, using Ingress resources and ExternalDNS allows us to save time, money and improve security.

January 17, 2022

9-Minute Read

Normally when we expose an application on EKS we use a LoadBalancer service to expose the application, the problem with this is every time we create a new LoadBalancer service, AWS will create a new ELB. Ingress controllers on EKS allow us to use one ELB and configure the application access using Kubernetes resources.

Creating a K8S Cluster The AWS Way

I created a lot of Kubernetes clusters using Terraform and Rancher. However, I prefer to use EKSCTL to create and manage K8S Clusters on AWS. EKSCTL is the official CLI for Amazon EKS and simplifies many things. On the other hand, it is pretty easy to upgrade the clusters, integrate with others features as ClusterAutoescaler, or configure secrets with KMS.

January 10, 2022

9-Minute Read

EKSCTL it is written in Go and makes use of CloudFormation under the hood. Also, it allows us to specify a manifest to replicate if we want to, and we can add it to our codebase just as almost any other IAC does.