Installing Docker on CentOS 7 and Understanding Image Layers

This guide covers setting up Docker on CentOS 7 and explains how Docker images work internally. System Requirements CentOS 7 requires a kernel version of 3.10 or higher. Installation Steps 1. Check Current Kernel Version uname -r 2. Update All Packages Ensure all existing packages are updated to their latest versions: yum -y update You can mo ...

Posted on Mon, 29 Jun 2026 16:39:17 +0000 by devilincarnated

Docker Fundamentals: A Comprehensive Guide

For this guide, we'll be using CentOS 7 as our base operating system. Step 1: Remove Old Docker Versions sudo yum remove docker \ docker-client \ docker-client-latest \ docker-common \ docker-latest \ docker-latest-logrotate \ docker-logr ...

Posted on Sun, 28 Jun 2026 17:15:25 +0000 by pieychpi

Understanding Jenkins Environment Variables in 10 Minutes

Jenkins sits at the heart of the DevOps toolchain, and CI/CD pipelines require writing Pipeline scripts. Getting started with Jenkins is straightforward—after a quick look at the documentation, concepts like agent, stages, and steps become clear, and you can quickly scaffold a pipeline. However, when filling in the details, particularly how to ...

Posted on Sun, 28 Jun 2026 16:45:07 +0000 by Yari

Introduction to Puppet: A Configuration Management System

Introduction to Puppet Overview Puppet is a centralized configuration management system designed for Linux and Unix platforms, utilizing a client-server architecture. It employs its own declarative language to manage system resources such as configuration files, users, cron jobs, packages, and services. The primary design goal of Puppet is to s ...

Posted on Sat, 27 Jun 2026 17:58:04 +0000 by gofeddy

Nginx Installation and Reverse Proxy Configuration

Nginx Overview Nginx is a high-performance HTTP server and reverse proxy known for low memory usage and strong concurrency support. It serves static content efficiently and handles dynamic content via CGI protocols like Perl and PHP, but requires Tomcat for Java applications. Optimized for high-load environments, Nginx supports up to 50,000 con ...

Posted on Mon, 22 Jun 2026 17:47:34 +0000 by dscapuano

Running Nested Docker Environments with DinD: Configuration and Workflow

The core mechanism behind Docker in Docker (DinD) involves spawning a fully independent Docker daemon inside an active container. The host container thus operates its own isolated Docker runtime, capable of building, shipping, and orchestrating child containers. While powerful, this pattern introduces extra resuorce consumption, potential secur ...

Posted on Sat, 20 Jun 2026 16:56:10 +0000 by finkrattaz

Essential Linux Commands for System Administration

Package Management with YUMOn RPM-based distributions like CentOS or RHEL, the yum package manager is the standard tool for software management.Installing Software:yum install package_name # Example: yum install htop Removing Software:yum remove package_name # Example: yum remove htop Searching for Packages: Supports fuzzy matching to find rele ...

Posted on Wed, 17 Jun 2026 16:36:47 +0000 by stockdalep

Configuring SaltStack Job Results Storage in MySQL

MySQL Client Installation Install the MySQL Python client package: yum install MySQL-python -y Master Configuration Edit /etc/salt/master to enable MySQL job caching: master_job_cache: mysql mysql.host: '10.240.17.103' mysql.user: 'salt' mysql.pass: 'salt' mysql.db: 'salt' mysql.port: 3306 MySQL Server Setup Install and configure MySQL server ...

Posted on Tue, 16 Jun 2026 17:30:23 +0000 by Hepp

Docker Installation Guide for CentOS

Prerequisites Supported CentOS Versions Docker is compatible with the following CentOS releases: CentOS 7 (64-bit) CentOS 6.5 (64-bit) or later versions System Requirements Docker requires specific kernel versions depending on your CentOS version: CentOS 7: 64-bit system with kernel version 3.10 or higher CentOS 6.5 or later: 64-bit system w ...

Posted on Tue, 09 Jun 2026 18:12:05 +0000 by davelr459

Understanding Docker Images, Containers, and Registries

Image Sources and Container Management Docker images can be categorized into two main types: Base System Images: Minimal operating system templates used as foundations Application Images: Pre-configured service images ready for deployment Creating base system images from templates: # Import CentOS 6 minimal template cat centos-6-x86-minimal.t ...

Posted on Tue, 09 Jun 2026 16:43:38 +0000 by minou