System Administration Basics

Manzolo PPA — My Personal Ubuntu Repository Install my tools directly with apt! Secure, GPG-signed repository hosted at https://ubuntu-repo.manzolo.it Ubuntu 24.04 (noble) — FULLY SUPPORTED wget -qO - https://ubuntu-repo.manzolo.it/KEY.gpg | sudo gpg --dearmor -o /etc/apt/trusted.gpg.d/manzolo-repo.gpg echo "deb [arch=amd64 signed-by=/etc/apt/trusted.gpg.d/manzolo-repo.gpg] https://ubuntu-repo.manzolo.it noble main" | sudo tee /etc/apt/sources.list.d/manzolo-repo.list sudo apt update Install my packages manzolo-chroot package sudo apt install manzolo-chroot Search all my tools apt search manzolo Verify everything works apt policy | grep manzolo Remove the repository (if you ever want to) sudo rm /etc/apt/sources.list.d/manzolo-repo.list sudo rm /etc/apt/trusted.gpg.d/manzolo-repo.gpg sudo apt update

Build Your Own Ubuntu Repository with Docker 📦 Ever wanted to distribute your own software packages just like Ubuntu does? Whether you’re managing internal tools across multiple servers, creating a private package distribution system, or just want to learn how APT repositories work under the hood, building your own Ubuntu repository is easier than you might think. In this guide, I’ll show you how to create a production-ready Ubuntu repository using Docker, complete with GPG signing, automated publishing, and a web interface for package distribution. ...

GPG Bash Playground Guide Introduction The GPG Bash Playground is an educational Bash script that demonstrates the practical use of GPG (GNU Privacy Guard) for key generation, public key exchange, encryption, and decryption. The script simulates a secure communication scenario by creating three users (Alice, Bob, and Carol), generating their GPG keys, exchanging public keys, and performing encrypted message exchanges. It includes comprehensive logging, error handling, and a debug mode for detailed output. This guide explains how to set up, run, and understand the script’s functionality. ...

Linux Boot Repair Guide (Debian/Ubuntu) Introduction Boot issues in Debian or Ubuntu can prevent your system from starting, often due to a corrupted GRUB bootloader, misconfigured partitions, or kernel problems. This guide provides step-by-step instructions to repair the boot process for both UEFI and Legacy (BIOS/MBR) systems using a live USB/CD. It covers GRUB reinstallation, partition setup, and troubleshooting common issues. Prerequisites A Debian or Ubuntu live USB/CD (preferably the same version as your system). Access to a live session by booting from the live media and selecting “Try Ubuntu/Debian.” Basic familiarity with the terminal. Administrative (root) privileges in the live environment. Critical Warning: Verify Partitions Before Formatting ⚠️Warning Extreme Caution: Before formatting any partition, use lsblk or fdisk -l to verify that you are selecting the correct disk and partition (e.g., EFI System Partition or root partition). Formatting the wrong partition can erase your data or critical files. Always double-check the disk and partition layout to avoid data loss. Linux Boot Repair UEFI Boot Repair UEFI systems use an EFI System Partition (ESP) to store GRUB and boot files. If the ESP is missing, corrupted, or misconfigured, the system may fail to boot. ...

Windows Boot Repair Guide Introduction Windows boot issues can prevent your system from starting correctly, often due to corrupted boot files, misconfigured partitions, or firmware settings. This guide provides step-by-step instructions to repair Windows boot problems for both UEFI and MBR/Legacy systems using the Windows Recovery Environment (WinRE) command prompt. It covers partition setup, boot configuration rebuilding, and troubleshooting common issues. Prerequisites A Windows installation USB or DVD with the same version as your system. Access to the Windows Recovery Environment (WinRE) by booting from the installation media and selecting “Repair your computer.” Basic familiarity with the Command Prompt. Administrative privileges in the recovery environment. Critical Warning: Verify Partitions Before Formatting ⚠️Warning Extreme Caution: Before formatting any partition, use diskpart’s list disk and list part commands to verify that you are selecting the correct disk and partition (e.g., the EFI System Partition or system partition). Formatting the wrong partition can erase your Windows data or other critical files. Always double-check the disk and partition layout to ensure you are not deleting your data drive. Windows Boot Repair UEFI Boot Repair UEFI systems use an EFI System Partition (ESP) to store boot files. If the ESP is missing, corrupted, or misconfigured, Windows may fail to boot. ...

Chroot Guide for Debian/Ubuntu Introduction A chroot (change root) environment allows you to switch the root directory of a Linux session to a different filesystem, enabling you to work within a broken or inaccessible Debian/Ubuntu system as if it were the active system. This is particularly useful for repairing boot issues, recovering files, updating configurations, or resetting passwords. This guide provides step-by-step instructions to set up a chroot environment from a Debian/Ubuntu live USB/CD. ...

APT Package Repository Management Guide Introduction Understanding where your installed packages come from is crucial for system maintenance, security auditing, and troubleshooting. This guide shows how to identify package sources, manage repositories, list packages by origin, and audit your APT installation on Debian/Ubuntu systems. What are Package Repositories? Package repositories are servers that host software packages for installation via APT (Advanced Package Tool). Understanding repository sources helps you: Security: Identify packages from untrusted sources Maintenance: Track PPA dependencies Troubleshooting: Find conflicting package sources System Cleanup: Remove unused repositories Documentation: Maintain installation records Repository Types Type Description Example Official Ubuntu/Debian main repositories archive.ubuntu.com PPA Personal Package Archives (Ubuntu) ppa.launchpad.net/user/repo Third-party External repositories download.docker.com Local Locally installed packages /var/lib/dpkg/status Prerequisites Debian or Ubuntu-based system Basic terminal knowledge apt, dpkg, and perl installed (usually pre-installed) 🚀 Quick Commands List All Packages with Repositories dpkg --get-selections | awk '!/deinstall$/ {print $1}' | \ xargs -I{} sh -c 'echo "=== $1 ===" && apt-cache policy "$1" | grep -E "^\s+\*\*\*" | head -1' -- {} | \ paste - - | sed 's/=== \([^ ]*\) ===/\1:/' | \ perl -pe 's/:\s+\*\*\*[^5]*500\s+/: /' | \ sed 's/\s\[.*\]$//' List Only PPA Packages dpkg --get-selections | awk '!/deinstall$/ {print $1}' | \ xargs -I{} apt-cache policy {} | \ perl -0777 -ne 'while(/^(\S+?):\n.*?\n\s+\*\*\*.*?500 http:\/\/ppa\.launchpad\.net\/([^\s\/]+)/gms) {print "$1: $2\n"}' Count Packages per Repository dpkg --get-selections | awk '!/deinstall$/ {print $1}' | \ xargs -I{} apt-cache policy {} 2>/dev/null | \ perl -0777 -ne 'while(/^(\S+?):\n.*?\n\s+\*\*\*.*?500\s+(http:\/\/[^\s]+)/gms) { $repo = $2; $repo =~ s/\s.*//; $repos{$repo}++ } END { for $r (sort keys %repos) { print "$r: $repos{$r} packages\n" } }' 📦 Complete Package Audit Script Full-featured bash script with multiple options Save as package-audit.sh: ...

APT and DPKG Guide (Debian/Ubuntu) Introduction apt and dpkg are core tools for package management on Debian and Ubuntu systems. apt update refreshes the package index from configured repositories, ensuring you have the latest package information. dpkg manages .deb packages, allowing direct installation, removal, querying, or identifying file ownership. This guide covers using apt update and dpkg, with use cases like system updates, manual .deb installation, searching for packages, finding file ownership, adding/removing external repositories, and determining which repository provides a package. ...

ZSH Installation and Configuration Guide (Debian/Ubuntu) Introduction ZSH (Z Shell) is a powerful, customizable shell designed for interactive use and scripting, offering enhanced features over Bash, such as advanced autocompletion, themes, and plugins. This guide explains how to install ZSH, set up Oh My Zsh (a popular framework for managing ZSH configurations), and configure the Powerlevel10k theme with plugins like syntax highlighting and autosuggestions on Debian/Ubuntu systems. It provides a streamlined setup for a modern, user-friendly shell experience. ...

RDP Installation and Configuration Guide (Debian/Ubuntu) Introduction Remote Desktop Protocol (RDP) enables remote access to a graphical desktop environment on a Linux system. XRDP is an open-source RDP server that allows connections from RDP clients (e.g., Windows Remote Desktop, Remmina) to a Debian/Ubuntu system. This guide explains how to install and configure XRDP with the XFCE desktop environment, a lightweight and efficient choice for remote desktops, on Debian/Ubuntu systems. It includes steps to set up a secure and functional RDP server for remote access. ...