Ubuntu Linux Bible - David Clinton - E-Book

Ubuntu Linux Bible E-Book

David Clinton

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Beschreibung

The latest version of the gold standard in Ubuntu Linux resources

In the freshly updated eleventh edition of Ubuntu Linux Bible, a team of veteran Linux educators delivers a comprehensive discussion of the Ubuntu Linux operating system. Perfect for absolute beginners and experienced users and server admins alike, this book explains the ins-and-outs of installing, configuring, maintaining, optimizing, and using Ubuntu systems.

This edition builds on the user-centric approach used by previous editions, showing you exactly how to perform common and essential tasks, like interfacing with popular IoT devices. The book covers:

  • Becoming a Linux power user: Using the Shell, navigating the filesystem, and more
  • Installing and configuring an Ubuntu Linux desktop or server
  • Linux server administration, including managing remote access and common desktop network configuration settings
  • Linux security techniques, including cryptography, PAM, and AppArmor

The Ubuntu Linux Bible is intuitively organized, allowing you to skip quickly to the section you need in the moment. It also covers the latest version of the popular Linux distribution – v24.04 at the time of writing – as well as the previous version. You'll also find:

  • Complete coverage of the enterprise and network functionality offered by Ubuntu, like web servers, networked file sharing, and DHCP and DNS management
  • Up-to-date explanations of desktop Ubuntu configuration, including user management, system backups, printer and device management, and wireless features
  • End-of-chapter exercises and questions, complete with answers, to help you develop your hands-on Ubuntu skillset

Perfect for Ubuntu Linux beginners and novice users, Ubuntu Linux Bible is also an essential resource for anyone transitioning from Windows desktops and servers looking for concise, accurate, and expert guidance in the Ubuntu OS.

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Table of Contents

Cover

Table of Contents

Title Page

Copyright

About the Authors

Acknowledgments

Introduction

Part I: Getting Started

Chapter 1: Starting with Linux

Understanding What Linux Is

Understanding How Linux Differs from Other Operating Systems

Exploring Linux History

Understanding How Linux Distributions Emerged

Finding Professional Opportunities with Linux Today

Summary

Chapter 2: Creating the Perfect Linux Desktop

Understanding Linux Desktop Technology

Starting with the GNOME 3 Desktop Live Image

Using the GNOME 3 Desktop

Summary

Exercises

Part II: Becoming a Linux Power User

Chapter 3: Using the Shell

About Shells and Terminal Windows

Choosing Your Shell

Running Commands

Recalling Commands Using Command History

Connecting and Expanding Commands

Using Shell Variables

Creating Your Shell Environment

Getting Information About Commands

Summary

Exercises

Chapter 4: Moving Around the Filesystem

Important Root-Level Linux Directories

Using Basic Filesystem Commands

Using Metacharacters and Operators

Listing Files and Directories

Understanding File Permissions and Ownership

Moving, Copying, and Removing Files

Summary

Exercises

Chapter 5: Working with Text Files

Editing Files with

vim

and

vi

Finding Files

Summary

Exercises

Chapter 6: Managing Running Processes

Understanding Processes

Listing Processes

Managing Background and Foreground Processes

Killing and Renicing Processes

Limiting Processes with cgroups

Summary

Exercises

Chapter 7: Writing Simple Shell Scripts

Understanding Shell Scripts

Summary

Exercises

Part III: Becoming a Linux System Administrator

Chapter 8: Learning System Administration

Understanding System Administration

Using Graphical Administration Tools

Invoking Administration Privileges

Exploring Administrative Commands, Configuration Files, and Log Files

Using Other Administrative Accounts

Checking and Configuring Hardware

Summary

Exercises

Chapter 9: Installing Linux

Choosing a Computer

Installing Ubuntu Desktop

Installing Ubuntu Server

Understanding Cloud-Based Installations

Installing Linux in the Enterprise

Exploring Common Installation Topics

Summary

Exercises

Chapter 10: Getting and Managing Software

Managing Software on the Desktop

Going Beyond the App Center

Understanding Linux Software Packaging

Working with Debian Packaging

Summary

Exercises

Chapter 11: Managing User Accounts

Creating User Accounts

Understanding Group Accounts

Managing Users in the Enterprise

Centralizing User Accounts

Summary

Exercises

Chapter 12: Managing Disks and Filesystems

Understanding Disk Storage

Partitioning Hard Disks

Using Logical Volume Manager Partitions

Mounting Filesystems

Using the

mkfs

Command to Create a Filesystem

Managing Storage with Cockpit

Summary

Exercises

Part IV: Becoming a Linux Server Administrator

Chapter 13: Understanding Server Administration

Getting Started with Server Administration

Checking and Setting Servers

Managing Remote Access with the Secure Shell Service

Configuring System Logging

Checking System Resources with

sar

Checking System Space

Managing Servers in the Enterprise

Summary

Exercises

Chapter 14: Administering Networking

Configuring Networking for Desktops

Configuring Networking from the Command Line

Configuring Networking in the Enterprise

Summary

Exercises

Chapter 15: Starting and Stopping Services

Understanding the Initialization Daemon (

init

or

systemd

)

Stopping and Starting Services

Enabling Persistent Services

Configuring a Default Runlevel or Target Unit

Adding New or Customized Services

Summary

Exercises

Chapter 16: Configuring a Print Server

Common Unix Printing System

Setting Up Printers

Working with CUPS Printing

Using Printing Commands

Configuring Print Servers

Summary

Exercises

Chapter 17: Configuring a Web Server

Understanding the Apache Web Server

Getting and Installing Your Apache Web Server

Controlling Apache

Troubleshooting Your Web Server

Exploring Web Server Deployment

Summary

Exercises

Chapter 18: Configuring an FTP Server

Understanding FTP

Installing the

vsftpd

FTP Server

Controlling the

vsftpd

Service

Configuring Your FTP Server

Using FTP Clients to Connect to Your Server

Summary

Exercises

Chapter 19: Configuring a Windows File Sharing (Samba) Server

Understanding Samba

Installing Samba

Controlling Samba

Securing Samba

Configuring Samba

Accessing Samba Shares

Using Samba in the Enterprise

Summary

Exercises

Chapter 20: Configuring an NFS File Server

Starting the NFS Service

Sharing NFS Filesystems

Securing Your NFS Server

Using NFS Filesystems

Unmounting NFS Filesystems

Summary

Exercises

Chapter 21: Troubleshooting Linux

Boot-Up Troubleshooting

Troubleshooting Software Packages

Troubleshooting Networking

Troubleshooting Memory

Troubleshooting in Rescue Mode

Summary

Exercises

Part V: Learning Linux Security Techniques

Chapter 22: Understanding Basic Linux Security

Implementing Physical Security

Monitoring Your Systems

Auditing and Reviewing Linux

Summary

Exercises

Chapter 23: Enhancing Linux Security with AppArmor

Understanding AppArmor

Working with AppArmor

Summary

Exercises

Chapter 24: Understanding Advanced Linux Security

Implementing Linux Security with Cryptography

Implementing Linux Security with PAM

Summary

Exercises

Chapter 25: Securing Linux on a Network

Auditing Network Services

Working with Firewalls

Summary

Exercises

Part VI: Engaging with Cloud Computing

Chapter 26: Shifting to Clouds and Containers

Understanding Virtualization

Understanding Linux Containers

Working with Linux Containers

Summary

Exercises

Chapter 27: Deploying Linux to the Cloud

Running Linux in the Cloud Using

cloud-init

Creating LXD Linux Images for Cloud Deployments

Using Amazon EC2 to Deploy Cloud Images

Summary

Exercises

Chapter 28: Automating Apps and Infrastructure with Ansible

Understanding Ansible

Exploring Ansible Components

Stepping Through an Ansible Deployment

Installing Ansible

Running Ad Hoc Ansible Commands

Summary

Exercises

Chapter 29: Deploying Applications as Containers with Kubernetes

Understanding Kubernetes

Trying Kubernetes

Enterprise-Quality Kubernetes with EKS

Summary

Exercises

Part VII: Appendixes

Appendix A: Exercise Answers

Chapter 2: Creating the Perfect Linux Desktop

Chapter 3: Using the Shell

Chapter 4: Moving Around the Filesystem

Chapter 5: Working with Text Files

Chapter 6: Managing Running Processes

Chapter 7: Writing Simple Shell Scripts

Chapter 8: Learning System Administration

Chapter 9: Installing Linux

Chapter 10: Getting and Managing Software

Chapter 11: Managing User Accounts

Chapter 12: Managing Disks and Filesystems

Chapter 13: Understanding Server Administration

Chapter 14: Administering Networking

Chapter 15: Starting and Stopping Services

Chapter 16: Configuring a Print Server

Chapter 17: Configuring a Web Server

Chapter 18: Configuring an FTP Server

Chapter 19: Configuring a Windows File Sharing (Samba) Server

Chapter 20: Configuring an NFS File Server

Chapter 21: Troubleshooting Linux

Chapter 22: Understanding Basic Linux Security

Chapter 23: Enhancing Linux Security with AppArmor

Chapter 24: Understanding Advanced Linux Security

Chapter 25: Securing Linux on a Network

Chapter 26: Shifting to Clouds and Containers

Chapter 27: Deploying Linux to the Cloud

Chapter 28: Automating Apps and Infrastructure with Ansible

Chapter 29: Deploying Applications as Containers with Kubernetes

Appendix B: Media

Getting Ubuntu

Booting Linux from a USB Drive

Index

End User License Agreement

List of Illustrations

Chapter 4

Figure 4.1 The Linux filesystem is organized as a hierarchy of directories.

Chapter 6

Figure 6.1 Displaying running processes with

top.

Figure 6.2 Use the System Monitor window to view and change running processes.

Figure 6.3 Renice, kill, or pause a process from the System Monitor window.

Chapter 8

Figure 8.1 View system activity and other topics from the Cockpit dashboard.

Chapter 10

Figure 10.1 Install and manage software packages from the Software window.

Chapter 11

Figure 11.1 Add and modify user accounts from Cockpit.

Chapter 12

Figure 12.1 LVM logical volumes can be mounted like regular partitions on a Linux filesystem.

Figure 12.2 View storage devices, filesystems, and activities from the Cockpit Storage page.

Figure 12.3 View and change disk partitions for a select storage device.

Figure 12.4 Format the new storage device.

Chapter 13

Figure 13.1 The System page of Cockpit.

Chapter 14

Figure 14.1 Viewing security for a wireless network using Gnome Settings.

Figure 14.2 Viewing and changing network settings from Cockpit.

Figure 14.3 Changing network settings with NetworkManager.

Figure 14.4 Setting up Firefox to use a proxy server.

Figure 14.5 Configuring networking with NetworkManager TUI.

Figure 14.6 Set static IP addresses by selecting Manual from the Edit Connection screen.

Chapter 16

Figure 16.1 CUPS provides a web-based administration tool.

Figure 16.2 You can do administration tasks from the Printers tab.

Chapter 17

Figure 17.1 The Ubuntu version of the Apache2 introduction page.

Figure 17.2 A custom HTML page within a simple Apache website.

Figure 17.3 The Certbot instructions page.

Chapter 18

Figure 18.1 The gFTP FTP client lets you see both sides of an FTP session.

Chapter 20

Figure 20.1 View NFS shares mounted locally using Cockpit Web UI.

Figure 20.2 Add a new NFS mount using Cockpit Web UI.

Chapter 21

Figure 21.1 Interrupt the GRUB boot loader to modify the boot process.

Figure 21.2 Snippet from

systemd-analyze

startup plot.

Chapter 24

Figure 24.1 Basic asymmetric key cryptography.

Chapter 25

Figure 25.1

gufw

Firewall Configuration window.

Chapter 27

Figure 27.1 Click to access the My Security Credentials page on the AWS management console.

Figure 27.2 Finding an available Ubuntu EC2 image ID on the console.

List of Tables

Chapter 3

Table 3.1 Keystrokes for navigating command lines

Table 3.2 Keystrokes for editing command lines

Table 3.3 Keystrokes for cutting pasting text from within command lines

Table 3.4 Keystrokes for using command history

Table 3.5 Common shell environment variables

Table 3.6 Bash configuration files

Table 3.7 Characters to add information to the

Bash

prompt

Table 3.8 Manual page sections

Chapter 4

Table 4.1 Commands for creating and using files

Table 4.2 Setting read, write, and execute permissions

Chapter 6

Table 6.1 Signals available in Linux

Chapter 7

Table 7.1 Operators for test expressions

Chapter 9

Table 9.1 Boot options for disabling features

Table 9.2 Boot options for video problems

Table 9.3 Boot options for VNC installations

Table 9.4 Assigning partitions to particular directories

Chapter 11

Table 11.1 Commands for creating and using files

Chapter 22

Table 22.1

chage

options

Table 22.2 Viewing log files that need special commands

Table 22.3 Additional filesystem scans

Table 22.4 Popular Linux intrusion detection systems

Chapter 24

Table 24.1 Cryptography ciphers

Table 24.2 Linux miscellaneous cryptography tools

Table 24.3 PAM contexts

Table 24.4 PAM configuration control flags and response handling

Guide

Cover

Table of Contents

Title Page

Copyright

About the Authors

Acknowledgments

Introduction

Begin Reading

Appendix A: Exercise Answers

Appendix B: Media

Index

End User License Agreement

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Ubuntu Linux® BIBLE

David Clinton

Christopher Negus

Eleventh Edition

Copyright © 2026 by John Wiley & Sons, Inc.  All rights reserved.

Published by John Wiley & Sons, Inc., Hoboken, New Jersey.

No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4470, or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permission.

The manufacturer’s authorized representative according to the EU General Product Safety Regulation is Wiley-VCH GmbH, Boschstr. 12, 69469 Weinheim, Germany, e-mail: [email protected].

Trademarks: Wiley and the Wiley logo are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries and may not be used without written permission. All other trademarks are the property of their respective owners. John Wiley & Sons, Inc. is not associated with any product or vendor mentioned in this book.

Limit of Liability/Disclaimer of Warranty: While the publisher and the authors have used their best efforts in preparing this work, including a review of the content of the work, neither the publisher nor the authors make any representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials or promotional statements for this work. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.

For general information on our other products and services or for technical support, please contact our Customer Care Department within the United States at (800) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002.

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic formats. For more information about Wiley products, visit our web site at www.wiley.com.

Library of Congress Cataloging-in-Publication Data has been applied for:

ISBN: 9781394349760 (Paperback)

ISBN: 9781394349784 (ePDF)

ISBN: 9781394349777 (epub)

Cover Image: © aleksandarvelasevic/Getty Images

About the Authors

David Clinton is a Linux server admin, AWS Solutions Architect, and data analyst who has worked with IT infrastructure in both academic and enterprise environments. He’s administered physical systems, containers, and networks using many Ubuntu flavors for nearly two decades. He has authored technology books—including AWS Certified Solutions Architect Study Guide: Associate SAA-C03 Exam (Sybex, 2022)—and created nearly a hundred video courses for Pluralsight teaching Linux administration, server virtualization, generative AI tools, and IT security.

In a previous life, David spent 20 years as a high school teacher. He currently lives in Toronto, Canada, with his wife and family and can be reached through his website: www.bootstrap-it.com.

Chris Negus is a principal technical writer for Red Hat, Inc. In his decades of working with Linux and Unix, Chris has taught hundreds of IT professionals to become certified Linux engineers, and he has written scores of documents on everything from Linux to virtualization to cloud computing and containerization.

Chris has also written and contributed to dozens of books on Linux and UNIX, including the Linux Bible (all editions), Linux Troubleshooting Bible, Red Hat Linux Bible (all editions), Docker Containers, CentOS Bible, Fedora Bible, Linux Toys, and Linux Toys II. Chris also co-authored several books for the Linux Toolbox series for power users: Ubuntu Linux Toolbox, Fedora Linux Toolbox, SUSE Linux Toolbox, Mac OS X Toolbox, and BSD UNIX Toolbox.

Before becoming an author and educator, Chris worked for eight years with the organization at AT&T that developed the Unix operating system before moving to Utah to help contribute to Novell’s UnixWare project in the early 1990s. When not writing about Linux, Chris enjoys playing soccer, hanging out with his wife, Sheree, and spending what time he can with his sons, Seth and Caleb.

Acknowledgments

Looking through the chapters of this book forces me to wonder at the size and ambition of the world of open source software. And that makes me think about all the thousands of developers, admins, architects, and—yes—writers who make this vast universe possible. This book is a testament to the hard work and community spirit of those individuals.

I would like to thank my wife for all her help and support through the long and demanding process of writing these books. And, once again, I’m indebted to all the great people at Wiley who helped me turn a plain old manuscript into a great teaching tool.

—David Clinton

When I was hired at Red Hat about a dozen years ago, I didn’t know that the organization would grow to about seven times its size, be bought by IBM for $34 billion, and (so far) still maintain the spirit of openness and excitement that it had when I first signed on. Every day when I come to work, I interact with many of the greatest Linux and cloud developers, testers, instructors, and support professionals in the world.

While I can’t thank everyone individually, there are a few people that I want to acknowledge in particular. I have the good fortune to take on so many cool and challenging projects because of the freedom that I receive from the people to whom I report at work. They include Michelle Bearer, Dawn Eisner, and Sam Knuth. Sam in particular has had my back and encouraged my work for more than a decade.

In my daily work, I want to give a shout out to my incredibly talented colleagues Scott McCarty, Ben Breard, Laurie Friedman, Dave Darrah, Micah Abbott, Steve Milner, Ian McLeod, Tom McKay, Joey Schorr, Bill Dettelback, Richa Marwaha, and Dirk Herrmann. Finally, a special thank you to Vikram Goyal, who luckily lives in Australia, so he is always available to bail me out when I blow up Git in the middle of the night.

As for Devon Lewis, Kelly Talbot, and the people at Wiley, thanks for letting me continue to develop and improve this book over the years. Thanks also to Margot Maley Hutchison from Waterside Productions for contracting the book for me with Wiley and always looking out for my best interests.

Finally, thanks to my wife, Sheree, for sharing her life with me and doing such a great job raising Seth and Caleb.

—Christopher Negus

Introduction

You can’t learn Ubuntu without using it. But if you’re ready for some serious hands-on research and experimentation, you can go a long way with this book. The Ubuntu Linux Bible is based on the 11th edition of Linux Bible, but has been refocused to ensure everything will work specifically on Ubuntu “right out of the box.”

Ubuntu may be the world’s most popular all-purpose Linux distribution. Canonical, the company that stands behind Ubuntu, reports that “Ubuntu powers millions of PCs worldwide.” It describes it as “the world’s most popular operating system across public clouds and OpenStack clouds” and “the #1 OS for containers.”

Most of the skills we’ll learn here will transfer well to other Linux distributions—and especially to distros like Debian, Mint, and Kali Linux that share upstream sources with Ubuntu.

So if you’re looking to get in on the action, stick around for the whole thing.

Beginner to certified professional:

As long as you have used a computer, mouse, and keyboard, you can reach good places using this book. We’ll show you how to get and install Ubuntu, quickly put it to productive use, use it to solve critical problems and build powerful server environments, and ultimately excel at administering and securing it.

System administrator focused:

When you’re finished with this book, you will know how to use, modify, and maintain Ubuntu. Almost all of the topics needed to achieve one or more Linux administration certifications are covered in this book. That said, many software developers and hobbyists will also enjoy it as they work to improve their skills.

Emphasis on command-line tools:

Although point-and-click graphic interfaces are as good or better as anything else these days, many advanced features can only be utilized by entering commands and editing configuration files manually. We’ll mostly focus on mastering the Linux command-line shell.

Many, many demos and exercises:

Instead of just telling you what Ubuntu does, we actually show you what it does. Then, to make sure that you’ve nailed it, you’ll have the opportunity to try it yourself. Every procedure and exercise has been tested to work in Ubuntu.

Ubuntu Linux Bible includes in-depth discussions covering server virtualization, infrastructure orchestration, and managing cloud and containerized applications (individually or at scale):

Cockpit administration web UI:

Since the dawn of the Linux age, people have struggled to develop simple graphical or browser-based interfaces for managing Linux systems. Cockpit may well have finally delivered a way to manage the basic Linux features through its web UI. Throughout this book, Cockpit will be our graphic tool of choice. With Cockpit, you can now add users, manage storage, monitor activities, and do many other administrative tasks through a single interface.

Cloud technologies:

Our coverage will include setting up your own Linux host for running virtual machines and running Linux in a cloud environment, such as Amazon Web Services. Linux is at the heart of most technological advances in cloud computing today. That means you need a solid understanding of Linux to work effectively in tomorrow’s data centers. The first chapters will cover all the Linux basics, which you’ll use through our various cutting-edge virtualization, networking, and storage administration exercises.

Ansible:

Automating tasks for managing systems is now an unavoidable part of modern digital administration. Using Ansible, you can create playbooks that define the state of a Linux system. This includes things like setting which packages are installed, which services are running, and how features are configured. A playbook can configure one system or a thousand systems, be combined to form a set of system services, and be run again to return a system to a defined state. You’ll be introduced to Ansible, create your first Ansible playbook, and run ad hoc Ansible commands.

Containers:

Packaging and running applications in containers is becoming the preferred method for deploying, managing, and updating small, scalable software services and features. You’ll learn how to pull container images, run them, stop them, and even build your own container images using LXD and Docker.

Kubernetes:

While containers are nice on their own, to be able to deploy, manage, and upgrade containers in a large enterprise you need an orchestration platform. The Kubernetes project provides a powerful platform for just that purpose.

How This Book Is Organized

The book is organized to enable you to start off at the very beginning with Linux and grow to become a professional Ubuntu system administrator and power user.

Part I, “Getting Started,” includes two chapters designed to help you understand what Linux is and get you started with an Ubuntu desktop:

Chapter 1

, “

Starting With Linux

,” covers topics such as what the Linux operating system is, where Ubuntu fits in, and how to get started using it.

Chapter 2

, “

Creating the Perfect Linux Desktop

,” provides information on how you can create a desktop system and use some of the most popular desktop features.

Part II, “Becoming a Linux Power User,” provides in-depth details on how to use the Linux shell, work with filesystems, manipulate text files, manage processes, and use shell scripts:

Chapter 3

, “

Using the Shell

,” includes information on how to access a shell, run commands, recall commands (using history), and do tab completion. The chapter also describes how to use variables, aliases, and man pages (traditional Linux command reference pages).

Chapter 4

, “

Moving Around the Filesystem

,” includes commands for listing, creating, copying, and moving files and directories. More advanced topics in this chapter include filesystem security, such as file ownership, permissions, and access control lists.

Chapter 5

, “

Working With Text Files

,” includes everything from basic text editors to tools for finding files and searching for text within files.

Chapter 6

, “

Managing Running Processes

,” describes how to see what processes are running on your system and change them. Ways of changing processes include killing, pausing, and sending other types of signals.

Chapter 7

, “

Writing Simple Shell Scripts

,” includes shell commands and functions that you can gather together into a file to run as a command itself.

In Part III, “Becoming a Linux System Administrator,” you learn how to administer Ubuntu systems:

Chapter 8

, “

Learning System Administration

,” provides information on basic graphical tools, commands, and configuration files for administering Ubuntu systems. It introduces the Cockpit web UI for simplified, centralized administration.

Chapter 9

, “

Installing Linux

,” covers common installation tasks, such as disk partitioning and initial software package selection, as well as more advanced installation tools.

Chapter 10

, “

Getting and Managing Software

,” provides an understanding of how software packages work and how to get and manage software packages.

Chapter 11

, “

Managing User Accounts

,” discusses tools for adding and deleting users and groups as well as how to centralize user account management.

Chapter 12

, “

Managing Disks and Filesystems

,” provides information on adding partitions, creating filesystems, and mounting filesystems, as well as working with logical volume management.

In Part IV, “Becoming a Linux Server Administrator,” you learn to create powerful network servers and the tools needed to manage them:

Chapter 13

, “

Understanding Server Administration

,” covers remote logging, monitoring tools, and the Linux boot process.

Chapter 14

, “

Administering Networking

,” discusses how to configure networking.

Chapter 15

, “

Starting and Stopping Services

,” provides information on process management tools—especially systemd.

Chapter 16

, “

Configuring a Print Server

,” describes how to configure printers to use locally on your Ubuntu system or over the network from other computers.

Chapter 17

, “

Configuring a Web Server

,” describes how to configure an Apache web server.

Chapter 18

, “

Configuring an FTP Server

,” covers procedures for setting up a vsftpd FTP server that can be used by others to download files from your Ubuntu system over the network.

Chapter 19

, “

Configuring a Windows File Sharing (Samba) Server

,” covers Windows file server configuration with Samba.

Chapter 20

, “

Configuring an NFS File Server

,” describes how to use Network File System features to share folders of files among systems over a network.

Chapter 21

, “

Troubleshooting Linux

,” covers popular tools for troubleshooting your Ubuntu system.

In Part V, “Learning Linux Security Techniques,” you learn how to secure your Linux systems and services:

Chapter 22

, “

Understanding Basic Linux Security

,” covers basic security concepts and techniques.

Chapter 23

, “

Enhancing Linux Security With AppArmor

,” provides information on using Pluggable Authentication Modules (PAM) and cryptology tools to tighten system security and authentication.

Chapter 24

, “

Understanding Advanced Linux Security

,” shows you how AppArmor can be configured to secure system services.

Chapter 25

, “

Securing Linux on a Network

,” covers network security features, such as the Uncomplicated Firewall (UFW) and

iptables

firewalls, to secure system services.

In Part VI, “Engaging with Cloud Computing,” the book pivots from a single-system focus toward containerization, cloud computing, and automation:

Chapter 26

, “

Shifting to Clouds and Containers

,” describes how to pull, push, start, stop, tag, and build container images.

Chapter 27

, “

Deploying Linux to the Cloud

,” describes how to deploy Ubuntu images to different cloud environments, including OpenStack, Amazon EC2, or a local Ubuntu system configured for virtualization.

Chapter 28

, “

Automating Apps and Infrastructure With Ansible

,” tells you how to create Ansible playbooks and run ad-hoc Ansible commands to automate the configuration of Ubuntu systems and other devices.

Chapter 29

, “

Deploying Applications as Containers With Kubernetes

,” describes the Kubernetes project and how it is used to orchestrate container images, with the potential to massively scale up for large data centers.

Part VII contains an appendix with Exercise Answers, providing sample solutions to the exercises included in Chapters 1 through 29.

Conventions Used in This Book

Throughout the book, special typography indicates code and commands. Commands and code are shown in a monospaced font:

This is how code looks.

In the event that an example includes both input and output, the monospaced font is still used, but input is presented in bold type to distinguish the two. Here’s an example:

$

ftp ftp.handsonhistory.com

Name (home:jake): jake

Password: ******

Commands that must be run using administrator permissions (often through sudo) will display a # command-line prompt, like this:

# nano /etc/group

All other commands will use the $ character, like this:

$ cat /etc/group

As for styles in the text:

New terms and important words appear in

italic

when introduced.

Keyboard strokes appear like this: Ctrl+A. This convention indicates to hold the Ctrl key as you also press the “a” key.

Filenames, URLs, and code within the text appear as follows:

persistence.properties

.

The following items call your attention to points that are particularly important.

NOTE

A Note box provides extra information to which you need to pay special attention.

TIP

A Tip box shows a special way of performing a particular task.

CAUTION

A Caution box alerts you to take special care when executing a procedure or damage to your computer hardware or software could result.

Jumping Into Linux

If you are new to Linux, you might have vague ideas about what it is and where it came from. You may have heard something about it being free (as in cost) or free (as in freedom to use it as you please). Before you start putting your hands on Linux (which we’ll do soon enough), Chapter 1 seeks to answer some of your questions about the origins and features of Linux and, in particular, Ubuntu.

Take your time and work through this book to get up to speed on Linux and how you can make it work to meet your needs. This is your invitation to jump in and take the first step toward becoming a Linux expert!

Visit the Ubuntu Linux Bible Website

To find links to various Linux distributions, tips on gaining Linux certification, and corrections to the book as they become available, go to www.wiley.com/go/ubuntulinuxbible.

How to Contact Wiley or the Authors

If you believe you’ve found a mistake in this book, please bring it to our attention. At John Wiley & Sons, we understand how important it is to provide our customers with accurate content, but even with our best efforts an error may occur.

In order to submit your possible errata, please email it to our Customer Service Team at [email protected] with the subject line “Possible Book Errata Submission.”

You can contact Christopher Negus at [email protected] and David Clinton at [email protected].

Part IGetting Started

IN THIS PART

Chapter 1

Starting with Linux

Chapter 2

Creating the Perfect Linux Desktop

CHAPTER 1Starting with Linux

IN THIS CHAPTER

Understanding what Linux is

Learning where Linux came from

Understanding Linux distributions

Exploring professional opportunities with Linux

Becoming certified in Linux

The operating systems war is over, and Linux has won. Proprietary operating systems simply cannot keep up with the pace of improvements and quality that Linux can achieve with its culture of sharing and innovation. Even Microsoft, whose former CEO Steve Ballmer once referred to Linux as “a cancer,” now says that Linux’s use on Microsoft’s Azure cloud computing service has surpassed the use of Windows.

Linux is one of the most important technological advancements of the 21st century. Beyond its impact on the growth of the Internet and its place as an enabling technology for a range of computer-driven devices, Linux development has become a model for how collaborative projects can surpass what single individuals and companies can do alone.

Google runs thousands upon thousands of Linux servers to power its search technology, along with billions of Linux containers. Its Android phones are based on Linux. Likewise, when you download and run Google’s Chrome OS, you get a browser that is backed by a Linux operating system.

Many of the largest companies on Earth—including Amazon, Netflix, NASA, and Facebook—rely on Linux for their internal servers. In fact, Facebook itself uses an open source development model, making source code for the applications and tools that drive Facebook available to the public. This model has helped Facebook shake out bugs quickly, get contributions from around the world, and fuel its exponential growth.

Financial organizations that have trillions of dollars riding on the speed and security of their operating systems also rely heavily on Linux. These include the New York Stock Exchange, Chicago Mercantile Exchange, and the Tokyo Stock Exchange.

As cloud continues to be one of the hottest buzzwords today, one part of the cloud that isn’t hype is that Linux and other open source technologies continue to be the foundation on which today’s greatest cloud innovations are being built. Every software component that you need to build a private or public cloud (such as hypervisors, cloud controllers, network storage, virtual networking, and authentication) is freely available from within the open source world.

The widespread adoption of Linux around the world has created huge demand for Linux expertise. This chapter starts you down a path to becoming a Linux—and Ubuntu—expert by helping you understand what Linux is, where it came from, and what your opportunities are for becoming proficient in it. The rest of this book provides you with hands-on activities to help you gain that expertise. The book’s final part will show you how to apply that expertise to cloud technologies, including automation tools and container orchestration technologies.

Understanding What Linux Is

In popular perception at least, Linux is a computer operating system (technically speaking, the name really only refers to the operating system kernel). An operating system consists of the software that manages your computer and lets you run applications on it. The features that make up Linux and similar computer operating systems include the following:

Detecting and preparing hardware:

When the Linux system boots up (when you turn on your computer), it looks at the components on your computer (CPU, hard drive, network cards, and so on) and loads the software (drivers and modules) needed to access those particular hardware devices.

Managing processes:

The operating system must keep track of multiple processes running at the same time and decide which have access to the CPU and when. The system also must offer ways of starting, stopping, and changing the status of processes.

Managing memory:

RAM and swap space (extended memory) must be allocated to applications as they need memory. The operating system decides how requests for memory are handled.

Providing user interfaces:

An operating system must provide ways of accessing the system. The first Linux systems were accessed from a command-line interpreter called a

shell

. Today, graphical desktop interfaces are commonly available as well.

Controlling filesystems:

Filesystem structures are built into the operating system (or loaded as modules). The operating system controls ownership and access to the files and directories (folders) that the filesystems contain.

Providing user access and authentication:

Creating user accounts and allowing boundaries to be set between users is a basic feature of Linux. Separate user and group accounts enable users to control their own files and processes.

Offering administrative utilities:

In Linux, hundreds (perhaps thousands) of commands and graphical windows are available to do such things as add users, manage disks, monitor the network, install software, and generally secure and manage your computer. Web UI tools, such as Cockpit, have lowered the bar for doing complex administrative tasks.

Starting up services:

To use printers, handle log messages, and provide a variety of system and network services, processes called

daemon processes

run in the background, waiting for requests to come in. Many types of services run in Linux. Linux provides different ways of starting and stopping these services. In other words, while Linux includes web browsers to view web pages, it can also be the computer that serves up web pages to others. Popular server features include web, mail, database, printer, file, DNS, and DHCP servers.

Programming tools:

A wide variety of programming utilities for creating applications and libraries for implementing specialty interfaces are available with Linux.

As someone managing Linux systems, you need to learn how to work with these features. While many of them can be managed using graphical interfaces, an understanding of the shell command line is critical for someone administering Linux systems.

Modern Linux systems now go way beyond what the first Unix systems (on which Linux was based) could do. Advanced features in Linux, often used in large enterprises, include the following:

Clustering:

Linux can be configured to work in clusters so that multiple systems can appear as one system to the outside world. Services can be configured to pass back and forth between cluster nodes while appearing to those using the services that they are running without interruption.

Virtualization:

To manage computing resources more efficiently, Linux can run as a virtualization host. On that host, you could run other Linux systems, Microsoft Windows, BSD, or other operating systems as virtual guests. To the outside world, each of those virtual guests appears as a separate computer. KVM and Xen are two technologies in Linux for creating virtual hosts.

Cloud computing:

To manage large-scale virtualization environments, you can use full-blown cloud computing platforms based on Linux. Projects such as OpenStack and Red Hat Virtualization (and its upstream oVirt project) can simultaneously manage many virtualization hosts, virtual networks, user and system authentication, virtual guests, and networked storage. Projects such as Kubernetes can manage containerized applications across massive data centers.

Real-time computing:

Linux can be configured for real-time computing, where high-priority processes can expect fast, predictable attention.

Specialized storage:

Instead of just storing data on the computer’s hard disk, you can store it on many specialized local and networked storage interfaces that are available in Linux. Shared storage devices available in Linux include iSCSI, Fibre Channel, and InfiniBand. Entire open source storage platforms include projects such as Ceph (

www.ceph.io

) and GlusterFS (

www.gluster.org

).

Some of these advanced topics are not covered in this book. However, the features covered here for using the shell, working with disks, starting and stopping services, and configuring a variety of servers should serve as a foundation for working with those advanced features.

Understanding How Linux Differs from Other Operating Systems

If you are new to Linux, chances are good that you have used a Microsoft Windows or macOS operating system. Although macOS had its roots in a free software operating system, referred to as the Berkeley Software Distribution (more on that later), operating systems from both Microsoft and Apple are considered proprietary operating systems. What that means is the following:

You cannot see the code used to create the operating system, and therefore, you cannot change the operating system at its most basic level if it doesn’t suit your needs, and you can’t use the operating system to build your own operating system from source code.

You cannot check the code to find bugs, explore security vulnerabilities, or simply learn what that code is doing.

You may not be able to plug your own software easily into the operating system if the creators of that system don’t want to expose the programming interfaces you need to the outside world.

You might look at those statements about proprietary software and say, “What do I care? I’m not a software developer. I don’t want to see or change how my operating system is built.”

That may be true. However, the fact that others can take free and open source software and use it as they please has driven the explosive growth of the Internet (think Google), mobile phones (think Android), special computing devices (think TiVo), and hundreds of technology companies. Free software has driven down computing costs and allowed for an explosion of innovation.

Maybe you don’t want to use Linux—as Google, Facebook, and other companies have done—to build the foundation for a multibillion-dollar company. Nonetheless, those companies and others who now rely on Linux to drive their computer infrastructures need more and more people with the skills to run those systems.

You may wonder how a computer system that is so powerful and flexible has come to be free as well. To understand how that could be, you need to see where Linux came from. Thus the next sections of this chapter describe the strange and winding path of the free software movement that led to Linux.

Exploring Linux History

Some histories of Linux begin with the following message, titled “What would you like to see most in minix?” posted by Linus Torvalds to the comp.os.minix newsgroup on August 25, 1991, at

http://groups.google.com/forum/#!msg/comp.os.minix/dlNtH7RRrGA/SwRavCzVE7gJ

Linus Benedict Torvalds

Hello everybody out there using minix -

I’m doing a (free) operating system (just a hobby, won’t be big and professional like gnu) for 386(486) AT clones. This has been brewing since April, and is starting to get ready. I’d like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of the file-system (due to practical reasons, among other things) … Any suggestions are welcome, but I won’t promise I’ll implement them :-)

Linus ([email protected])

PS. Yes—it’s free of any minix code, and it has a multi-threaded fs. It is NOT portable[sic] (uses 386 task switching etc), and it probably never will support anything other than AT-hard disks, as that’s all I have :-(.

Minix was a Unix-like operating system that ran on PCs in the early 1990s. Like Minix, Linux was also a clone of the Unix operating system. With few exceptions, such as Microsoft Windows, most modern computer systems (including macOS and Linux itself) were derived from Unix operating systems, created originally by AT&T.

To truly appreciate how a free operating system could have been modeled after a proprietary system from AT&T Bell Laboratories, it helps to understand the culture in which Unix was created and the chain of events that made the essence of Unix possible to reproduce freely.

NOTE

To learn more about how Linux was created, pick up the book Just for Fun: The Story of an Accidental Revolutionary by Linus Torvalds (Harper Collins Publishing, 2001).

Free-Flowing Unix Culture at Bell Labs

The Unix operating system was created and, from the very beginning, nurtured in a communal environment. Its creation was not driven by market needs but by a desire to overcome impediments to producing programs. AT&T, which owned the Unix trademark originally, eventually made Unix into a commercial product. By that time, however, many of the concepts (and even much of the early code) that made Unix special had fallen into the public domain.

If you are not old enough to remember when AT&T split up in 1984, you may not remember a time when AT&T was the phone company. Up until the early 1980s, AT&T didn’t have to think much about competition because if you wanted a phone in the United States, you had to go to AT&T. It had the luxury of funding pure research projects. The mecca for such projects was the Bell Laboratories site in Murray Hill, New Jersey.

After a project called Multics failed around 1969, Bell Labs employees Ken Thompson and Dennis Ritchie set off on their own to create an operating system that would offer an improved environment for developing software. Up to that time, most programs were written on paper punch cards that had to be fed in batches to mainframe computers. In a 1980 lecture on “The Evolution of the UNIX Time-Sharing System,” Dennis Ritchie summed up the spirit that started Unix:

What we wanted to preserve was not just a good environment in which to do programming, but a system around which a fellowship could form. We knew from experience that the essence of communal computing as supplied by remote-access, time-shared machines is not just to type programs into a terminal instead of a keypunch, but to encourage close communication.

The simplicity and power of the Unix design began breaking down barriers that, until this point, had impeded software developers. The foundation of Unix was set with several key elements:

The Unix filesystem:

Because it included a structure that allowed levels of subdirectories (which, for today’s desktop users, look like folders inside of folders), Unix could be used to organize the files and directories in intuitive ways. Furthermore, complex methods of accessing disks, tapes, and other devices were greatly simplified by representing those devices as individual device files that you could also access as items in a directory.

Input/output redirection: Early Unix systems also included input redirection and pipes. From a command line, Unix users could direct the output of a command to a file using a right-arrow key (>). Later, the concept of pipes (|) was added where the output of one command could be directed to the input of another command. For example, the following command line concatenates (cat) file1 and file2, sorts (sort) the lines in those files alphabetically, paginates the sorted text for printing (pr), and directs the output to the computer’s default printer (lp):

$ cat file1 file2 | sort | pr | lp

This method of directing input and output enabled developers to create their own specialized utilities that could be joined with existing utilities. This modularity made it possible for lots of code to be developed by lots of different people. A user could just put together the pieces they needed.

Portability:

Simplifying the experience of using Unix also led to it becoming extraordinarily portable to run on different computer hardware. By having device drivers (represented by files in the filesystem tree), Unix could present an interface to applications in such a way that the programs didn’t have to know about the details of the underlying hardware. To port Unix later to another system, developers had only to change the drivers. The application programs didn’t have to change for different hardware!

To make portability a reality, however, a high-level programming language was needed to implement the software. To that end, Brian Kernighan and Dennis Ritchie created the C programming language. In 1973, Unix was rewritten in C. Today, C is still the primary language used to create the Unix (and Linux) operating system kernels.

As Ritchie went on to say in a 1979 lecture (www.nokia.com/bell-labs/about/dennis-m-ritchie/hist.html):

Today, the only important Unix program still written in assembler is the assembler itself; virtually all the utility programs are in C, and so are most of the application’s programs, although there are sites with many in Fortran, Pascal, and Algol 68 as well. It seems certain that much of the success of Unix follows from the readability, modifiability, and portability of its software that in turn follows from its expression in high-level languages.

If you are a Linux enthusiast and are interested in what features from the early days of Linux have survived, an interesting read is Dennis Ritchie’s reprint of the first Unix programmer’s manual (dated November 3, 1971). You can find it at Dennis Ritchie’s website: www.bell-labs.com/usr/dmr/www/1stEdman.html. The form of this documentation is Unix man pages, which is still the primary format for documenting Unix and Linux operating system commands and programming tools today.

What’s clear as you read through the early documentation and accounts of the Unix system is that the development was a free-flowing process, lacked ego, and was dedicated to making Unix excellent. This process led to a sharing of code (both inside and outside of Bell Labs), which allowed rapid development of a high-quality Unix operating system. It also led to an operating system that AT&T would find difficult to reel back in later.

Commercial Unix

Before the AT&T divestiture in 1984, when it was split up into AT&T and seven “Baby Bell” companies, AT&T was forbidden to sell computer systems with software. Companies that would later become Verizon, Qwest, Nokia, and Alcatel-Lucent were all part of AT&T. As a result of AT&T’s monopoly of the telephone system, the U.S. government was concerned that an unrestricted AT&T might dominate the fledgling computer industry.

Because AT&T was restricted from selling computers directly to customers before its divestiture, Unix source code was licensed to universities for a nominal fee. This allowed Unix installations to grow in size and mindshare among top universities. However, there was still no Unix operating system for sale from AT&T that you didn’t have to compile yourself.

Berkeley Software Distribution Arrives

In 1975, Unix V6 became the first version of Unix available for widespread use outside of Bell Laboratories. From this early Unix source code, the first major variant of Unix was created at the University of California, Berkeley. It was named the Berkeley Software Distribution (BSD).

For most of the next decade, the BSD and Bell Labs versions of Unix headed off in separate directions. BSD continued forward in the free-flowing, share-the-code manner that was the hallmark of the early Bell Labs Unix, whereas AT&T started steering Unix toward commercialization. With the formation of a separate Unix Laboratory, which moved out of Murray Hill and down the road to Summit, New Jersey, AT&T began its attempts to commercialize Unix. By 1984, divestiture was behind AT&T, and it was ready to start selling Unix.

Unix Laboratory and Commercialization

The Unix Laboratory was considered a jewel that couldn’t quite find a home or a way to make a profit. As it moved between Bell Laboratories and other areas of AT&T, its name changed several times. It is probably best remembered by the name it had as it began its spin-off from AT&T: Unix System Laboratories (USL).

The Unix source code that came out of USL, the legacy of which was sold in part to Santa Cruz Operation (SCO), was used for a time as the basis for ever-dwindling lawsuits by SCO against major Linux vendors (such as IBM and Red Hat, Inc.). Because of that, it’s possible that the efforts from USL that have contributed to the success of Linux are lost on most people.

During the 1980s, of course, many computer companies were afraid that a newly divested AT&T would pose more of a threat to controlling the computer industry than would an upstart company in Redmond, Washington. To calm the fears of IBM, Intel, Digital Equipment Corporation, and other computer companies, the Unix Lab made the following commitments to ensure a level playing field:

Source code only:

Instead of producing its own boxed set of Unix, AT&T continued to sell source code only and to make it available equally to all licensees. Each company would then port Unix to its own equipment. It wasn’t until about 1992, when the lab was spun off as a joint venture with Novell (called Univel), and then eventually sold to Novell, that a commercial boxed set of Unix (called UnixWare) was produced directly from that source code.

Published interfaces: