Kubernetes offers various automatic scaling mechanisms, such as Horizontal Pod Autoscaling (HPA), which dynamically adjusts the number of Pod replicas based on different conditions. This capability enables Pods to handle current traffic efficiently without the constant intervention of administrators to adjust the replica count. Apart from HPA, Kubernetes also provides…

What Is DevOps In the field of DevOps, the most common question that arises is: What exactly is “DevOps”? How does it differ from a “DevOps Engineer”? Why do job postings often mention roles like “DevOps/SRE Engineer”? Is it a job title, a skill set, or a cultural shift? From my personal understanding…

This article outlines how to preserve container images on nodes, bypassing the Kubelet image garbage collection (GC) phase. Use Cases In certain deployment environments (airgap), images cannot be fetched over the network. Hence, container images must be preloaded into nodes. Containers are deployed using the “ImagePullPolicy:Never” approach, requiring related images to be…

Introduction This article documents how to explore the latest sidecar container functionality in Kubernetes 1.28. Sidecar Container is a well-known and common design pattern in Kubernetes, where multiple containers are deployed inside a Pod. The Sidecar Container assists the main container in various functions, such as: Network Proxy: For example, in…

Introduction This article documents the installation of Spark SQL and Spark Thrift Server on Kubernetes within a Google Kubernetes Engine (GKE) environment. It outlines the use of Google Cloud Storage (GCS) as the data source for Spark SQL and the communication with Spark SQL through JDBC-compatible applications. The purpose of this…

Preface One evening recently, I was researching ICMP packets using the ping command. Suddenly, I had an unexpected inspiration and decided to remove the capabilities from the ping command. Surprisingly, the ping command continued to function perfectly, which was a result I had not anticipated. After all, ICMP packets were not…

Introduction With the increasing popularity of GitOps, solutions like ArgoCD, Flux, etc., have helped numerous Kubernetes environments address the challenges and processes of Continuous Deployment (CD). However, GitOps, which combines Git and Operations (Ops), involves varying ways of utilizing Git depending on the environment and team. This article attempts to organize…

Introduction In addition to the basic Pod types, Kubernetes offers a variety of higher-level workload types, such as Deployment, DaemonSet, and StatefulSet. These higher-level controllers allow you to provide services with multiple replicas of your Pods, making it easier to achieve a high availability architecture. However, when Kubernetes nodes experience failures…

Preface Kubernetes in Docker (KIND) is an open-source project maintained within the Kubernetes SIG community. The purpose of this project is to provide a simple Kubernetes environment using Docker, primarily for Kubernetes CI testing. Kubernetes itself is a container orchestration platform, so using Docker as its nodes results in an architecture…