Category Archives: Kubernetes

Kubernetes is an open-source container orchestration system for automating application deployment, scaling, and management.

Terraform: EKS and Karpenter version upgrade 19.21 to 20.0

13 July 2024

 It seems like a common task to update a version of a Terraform module, but terraform-aws-modules/eks version 20.0 had some pretty big changes with breaking changes. The changes relate to authentication and authorization in AWS IAM and AWS EKS, which I analyzed in the post AWS: Kubernetes and Access Management API, the new authentication in… Read More »

Kubernetes: monitoring Events with kubectl and Grafana Loki

23 June 2024

  In Kubernetes, in addition to metrics and logs from containers, we can get information about the operation of components using Kubernetes Events. Events usually store information about the status of Pods (creation, evict, kill, ready or not-ready status of pods), WorkerNodes (status of servers), Kubernetes Scheduler (inability to start a pod, etc.). Kubernetes Events… Read More »

AWS: Karpenter and SSH for Kubernetes WorkerNodes

23 June 2024

  We have an AWS EKS cluster with WorkerNodes/EC2 created with Karpenter. The process of creating the infrastructure, cluster, and launching Karpenter is described in previous posts: Terraform: Building EKS, part 1 – VPC, Subnets and Endpoints Terraform: Building EKS, part 2 – an EKS cluster, WorkerNodes, and IAM Terraform: Building EKS, part 3 –… Read More »

Helm: UPGRADE FAILED: another operation (install/upgrade/rollback) is in progress

24 May 2024

 Sometimes, when deploying Helm charts, the error “UPGRADE FAILED: another operation (install/upgrade/rollback) is in progress” may appear: It can occur because the previous deployment failed due to errors in the chart, or the connection between the build machine and the Kubernetes cluster was lost. Check the release status with ls –all: $ helm -n dev-backend-api-ns… Read More »

AWS: VPC Flow Logs, NAT Gateways, and Kubernetes Pods – a detailed overview

5 May 2024

 We have a relatively large spending on AWS NAT Gateway Processed Bytes, and it became interesting to know what exactly is processed through it. It would seem that everything is simple – just turn on VPC Flow Logs and see what’s what. But when it comes to AWS Elastic Kubernetes Service and NAT Gateways, things… Read More »

Kubernetes: tracing requests with AWS X-Ray, and Grafana data source

2 March 2024

 Tracing allows you to track requests between components, that is, for example, when using AWS and Kubernetes we can trace the entire path of a request from AWS Load Balancer to Kubernetes Pod and to DynamoDB or RDS. This helps us both to track performance issues – where and which requests are taking a long… Read More »

AWS: VPC Prefix and the maximum of Pods on Kubernetes WorkerNodes

29 February 2024

 Each WorkerNode in a Kubernetes cluster can have a limited number of Pods running, and this limit is determined by three parameters: CPU: the total number of requests.cpu cannot be more than the number of CPUs on the Node Memory: the total number of requests.memory cannot be more than the Memory on the Node IP:… Read More »

Terraform: creating a module for collecting AWS ALB logs in Grafana Loki

24 February 2024

 An example of creating a Terraform module to automate log collection from AWS Load Balancers in Grafana Loki. See how the scheme works in the Grafana Loki: collecting AWS LoadBalancer logs from S3 with Promtail Lambda blog. In short, ALB writes logs to an S3 bucket, from where they are picked up by a Lambda… Read More »

Karpenter: its monitoring, and Grafana dashboard for Kubernetes WorkerNodes

18 February 2024

 We have an AWS Elastic Kubernetes Service cluster with Karpenter which is responsible for EC2 auto-scaling, see AWS: Getting started with Karpenter for autoscaling in EKS, and its installation with Helm. In general, there are no problems with it so far, but in any case we need to monitor it. For its monitoring, Karpenter provides… Read More »