Why the GKE metadata server failed to work, and how we fixed it — Overview Someday, after our Google Kubernetes Engine (GKE) cluster was updated automatically, the GKE metadata server went down for nearly a day. As a result, the kube-dns (Kubernetes DNS service) Pods kept restarting, and services in the cluster were unavailable. This post will detail the outage, explain what caused it, and…

In this article, we will talk about how to create a simple Kubernetes Custom Resource by creating a Custom Resource Definition(CRD) with kubectl. The following topics are covered in this blog. What is a Kubernetes Resource What is a Custom Resource(CR) What is a CustomResourceDefinition(CRD) Create a CustomResourceDefinition Create a…

An overview of Kube-controller-manager source code — Kube-controller-manager Kube-controller-manager is a binary that runs controllers, which are control loops shipped with Kubernetes. Examples of controllers are the Deployment Controller, Service Controller, Job Controller, Namespace Controller, ReplicaSet Controller, Endpoints Controller, and so on. 1. Introduction This article provides an overview of kube-controller-manager source code in…

TLDR: The limit is 1MB from the etcd side which is where Kubernetes stores its objects. etcd is designed to handle small key value pairs typical for metadata. Larger requests may increase the latency of other requests. The size of the individual K8s Secret and ConfigMap are limited to 1MiB…

A powerful open-source Developer Portal platform — 1. What is a Developer Portal? The Developer Portal is an internal website that helps developers learn about and use their services, tools, and documentation. It contains all the information and tools that a developer might need and makes it easily searchable and accessible. Developer Portals help developers work quickly, efficiently, and happily.

How to enable Gzip Compression to Speed Up Argo CD Web UI — Argo CD is a powerful GitOps continuous delivery tool for Kubernetes. However, Argo CD Web UI is very slow when managing a lot of Applications. How can we faster the Web UI ?

Simple timing in Golang A simple way to measure execution time in Golang is to use the time.Now() and time.Since() functions: func main() { start := time.Now() time.Sleep(time.Second * 3) elapsed := time.Since(start) fmt.Printf("Time took %s", elapsed) } A Timing function using a deferred function Here is an example program using a deferred function MeasureTime() to measure execution time: import (…

A high-level overview of Kubernetes API resources — Kubernetes API Overview The core of Kubernetes’ control plane is the API server. The API server exposes a RESTful API. The REST API is the fundamental fabric of Kubernetes. All operations and communications between components, and external user commands are REST API calls that the API Server handles. Consequently, everything in the Kubernetes…

Merge Multiple Kubernetes kubectl config files into a single — When accessing multiple Kubernetes clusters, you will have many kubeconfig files. By default, kubectl only looks for a file named config in the $HOME/.kube directory. So, how can we merge many kubeconfig files into one? Here are the few steps: 1. Make a copy of your kubeconfig file cp ~/.kube/config…