Bashes on Manzolo Code Notes

Docker and Docker Compose

Fri, 26 Sep 2025 10:00:00 +0100

Docker and Docker Compose Guide

Introduction

Docker is a platform for developing, shipping, and running applications inside containers. Docker Compose is a tool for defining and running multi-container Docker applications using YAML files. This guide covers essential Docker and Docker Compose commands, with practical examples, to help you manage containers effectively.

What is Docker?

Docker allows you to package applications with their dependencies into containers, ensuring consistency across different environments. Containers are lightweight, portable, and run independently of the host system.

Git

Fri, 26 Sep 2025 10:00:00 +0100

Git and Gitflow Guide

Introduction

Git is a distributed version control system that enables multiple developers to collaborate on projects efficiently. Gitflow is a popular branching model that organizes Git branches for streamlined development and release management. This guide covers essential Git commands, introduces the Gitflow workflow, and provides practical examples for managing code repositories.

What is Git?

Git tracks changes to files, allowing multiple users to work on the same project without conflicts. It supports branching, merging, and version history, making it ideal for software development and collaborative projects.

Linux Sysadmin Commands Guide

Fri, 26 Sep 2025 10:00:00 +0100

Linux Sysadmin Commands Guide

Introduction

As a Linux system administrator, mastering essential commands is crucial for managing servers, monitoring systems, and troubleshooting issues. This guide covers fundamental Linux commands for system administration, focusing on user management, process control, network diagnostics, and system monitoring, with practical examples.

Prerequisites

A Linux system (e.g., Ubuntu, CentOS, or Debian).
Root or sudo privileges.
Basic familiarity with the terminal.

System Information

Hardware and System Overview

# Display system information
uname -a

# Show CPU details
lscpu
cat /proc/cpuinfo

# Display memory usage
free -h
cat /proc/meminfo

# List block devices (disks)
lsblk
fdisk -l # Requires sudo

# Show mounted filesystems
df -h

System Uptime and Load

# Display system uptime and load average
uptime

# Show load average
cat /proc/loadavg

# Interactive system monitoring
top
htop # If installed

User and Group Management

Managing Users

# Add a new user
sudo useradd -m -s /bin/bash username

# Set a password for the user
sudo passwd username

# Modify user details
sudo usermod -aG groupname username # Add user to a group
sudo usermod -s /bin/zsh username # Change shell

# Delete a user
sudo userdel -r username # Remove user and home directory

Managing Groups

# Create a new group
sudo groupadd groupname

# Add user to a group
sudo usermod -aG groupname username

# List groups
getent group

# Delete a group
sudo groupdel groupname

Example: Creating a User with Specific Permissions

Create a user devuser with sudo privileges:

QEMU Disk Image and VM Management Guide

Fri, 26 Sep 2025 10:00:00 +0100

QEMU Disk Image and VM Management Guide

Introduction

QEMU is a powerful open-source emulator and virtualizer for running virtual machines (VMs) and managing disk images on Linux systems. It supports a wide range of architectures and provides tools for creating, manipulating, and running VMs with flexible configurations. This guide covers essential QEMU commands for disk image management and VM operations, with practical examples for system administrators and developers.

Prerequisites

QEMU installed on a Linux system (qemu-system-x86_64 --version to verify).
Root or sudo privileges for certain operations (e.g., installing QEMU or accessing KVM).
Basic understanding of Linux terminal commands and virtualization concepts.

Install QEMU on Ubuntu/Debian:

SSH Forward Tunneling

Fri, 26 Sep 2025 10:00:00 +0100

SSH Forward Tunneling Guide

Introduction

SSH forward tunneling (also known as local port forwarding) allows you to securely connect to a remote service through an SSH server, making it appear as if the service is running on your local machine. This is useful for accessing services on a remote server or another machine in a secure network that aren’t directly accessible.

In this guide, we’ll cover the basics of SSH forward tunneling, explain how it works, and provide practical examples.

Uncomplicated Firewall

Fri, 26 Sep 2025 10:00:00 +0100

Ubuntu UFW Firewall Guide

Introduction

UFW (Uncomplicated Firewall) is a user-friendly interface for managing iptables firewall rules on Ubuntu systems. It simplifies the process of configuring firewall settings, making it accessible for beginners and efficient for advanced users. This guide covers essential UFW commands, practical examples, and tips for securing your Ubuntu server.

What is UFW?

UFW is a front-end for iptables, designed to make firewall configuration straightforward. It allows you to manage inbound and outbound network traffic by defining rules based on ports, protocols, and IP addresses.

Essential Bash Commands - File Management and System Analysis

Thu, 25 Sep 2025 10:00:00 +0100

Learn fundamental Bash commands for file management and system analysis that every developer should know