Posts on Menra Romial

A Comprehensive Guide to powercap-utils on Linux

Thu, 23 Oct 2025 13:00:00 +0000

1. Introduction: What is `powercap-utils`?

powercap-utils is a suite of user-space command-line tools for Linux that allow you to interact with the kernel’s Power Capping Framework. This framework provides a standardized way to monitor and limit the power consumption of hardware devices.

Its most common use is to control Intel’s Running Average Power Limit (RAPL) and AMD’s RAPL-like features on modern CPUs. These features let you directly set power budgets for the CPU package, its cores, and DRAM.

Building a Kubernetes Controller with Kubebuilder from Scratch

Mon, 22 Sep 2025 10:30:00 +0000

In this tutorial, you will learn how to build a custom Kubernetes controller (also known as an Operator) using Kubebuilder. We will create a Custom Resource Definition (CRD) for a simple Website resource. The goal of our controller will be to watch for these Website resources and, for each one, create a corresponding Kubernetes Deployment and Service.

This is a powerful pattern that allows you to extend the Kubernetes API to manage your own applications declaratively.

Guide to Building a Custom Kubernetes Scheduler

Sun, 24 Aug 2025 17:30:00 +0000

This guide will walk you through creating a custom scheduler plugin that influences where pods are placed based on custom logic. We will build a simple “Network-Aware” plugin that prefers to schedule pods on nodes with a specific network label.

What We Will Build:

A Filter plugin: It will only allow pods that request high-speed networking to be scheduled on nodes that are labeled as network-topology=high-speed.
A Score plugin: It will give a higher score to nodes with the high-speed label, making them more desirable.
We will then package this plugin into a new scheduler binary, containerize it, and deploy it to a local Kubernetes cluster.

Part 1: Understanding the Foundations - The Scheduling Framework

Before writing any code, it’s crucial to understand the “why” and “how”.

Master the CI/CD Pipeline Locally

Wed, 20 Aug 2025 10:30:00 +0000

Welcome to this comprehensive course on DevOps culture and tooling. The goal is to guide you, step-by-step, from theory to practice, empowering you to build, secure, and automate a full Continuous Integration and Continuous Deployment (CI/CD) pipeline.

Course Philosophy: Everything we learn will be put into practice in a 100% local lab environment, running on your own machine using Docker. You will not need any cloud accounts or paid services. Every concept is illustrated with hands-on workshops and concrete examples.

Setting Up a Kubernetes Cluster with Kubeadm and CRI-O

Tue, 25 Mar 2025 16:40:16 +0000

Prerequisites

Before setting up a Kubernetes cluster using Kubeadm and CRI-O, ensure that you meet the following requirements:

Hardware Requirements

At least 2 GB of RAM per node (4 GB recommended for the master node)
At least 2 CPUs per node
20 GB of free disk space
A stable internet connection
All nodes should be able to communicate with each other

Software Requirements

A supported Linux distribution (Ubuntu 20.04+ or Debian 10+ recommended)
User access with sudo privileges
Basic understanding of Linux command-line interface (CLI)
Knowledge of networking concepts

Step 1: Configure Kernel Parameters

Kubernetes requires some kernel parameters to be set to allow IPtables to see bridged traffic.

Setting Up a K3s Cluster with a Hello-World Deployment

Sun, 07 Jul 2024 14:30:00 +0000

This tutorial will guide you through setting up a K3s cluster with one master node and two worker nodes, deploying a simple “Hello-World” application, and utilizing various kubectl commands to manage and inspect Kubernetes resources.

Posts on Menra Romial

A Comprehensive Guide to powercap-utils on Linux

1. Introduction: What is `powercap-utils`?

Building a Kubernetes Controller with Kubebuilder from Scratch

Guide to Building a Custom Kubernetes Scheduler

Part 1: Understanding the Foundations - The Scheduling Framework

Master the CI/CD Pipeline Locally

Setting Up a Kubernetes Cluster with Kubeadm and CRI-O

Prerequisites

Hardware Requirements

Software Requirements

Step 1: Configure Kernel Parameters

Setting Up a K3s Cluster with a Hello-World Deployment

Prerequisites

Step 1: Installing K3s

Install K3s on the Master Node

Posts on Menra Romial

A Comprehensive Guide to powercap-utils on Linux

1. Introduction: What is powercap-utils?

Building a Kubernetes Controller with Kubebuilder from Scratch

Guide to Building a Custom Kubernetes Scheduler

Part 1: Understanding the Foundations - The Scheduling Framework

Master the CI/CD Pipeline Locally

Setting Up a Kubernetes Cluster with Kubeadm and CRI-O

Prerequisites

Hardware Requirements

Software Requirements

Step 1: Configure Kernel Parameters

Setting Up a K3s Cluster with a Hello-World Deployment

Prerequisites

Step 1: Installing K3s

Install K3s on the Master Node

1. Introduction: What is `powercap-utils`?