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