Quickly learn how to use Ubuntu, the fastest growing Linux distribution, in a personal or enterprise environment
Whether you're a newcomer to Linux or an experienced system administrator, the Ubuntu Linux Bible provides what you need to get the most out of one the world's top Linux distributions. Clear, step-by-step instructions cover everything from installing Ubuntu and creating your desktop, to writing shell scripts and setting up file sharing on your network. This up-to-date guide covers the latest Ubuntu release with long-term support (version 20.04) as well as the previous version. Throughout the book, numerous examples, figures, and review questions with answers ensure that you will fully understand each key topic.
Organized into four parts, the book offers you the flexibility to master the basics in the "Getting Started with Ubuntu Linux" section, or to skip directly to more advanced tasks. "Ubuntu for Desktop Users" shows you how to setup email, surf the web, play games, and create and publish documents, spreadsheets, and presentations. "Ubuntu for System Administrators" covers user administration, system backup, device management, network configuration, and other fundamentals of Linux administration. The book's final section, "Configuring Servers on Ubuntu," teaches you to use Ubuntu to support network servers for the web, e-mail, print services, networked file sharing, DHCP (network address management), and DNS (network name/address resolution). This comprehensive, easy-to-use guide will help you:
- Install Ubuntu and create the perfect Linux desktop
- Use the wide variety of software included with Ubuntu Linux
- Stay up to date on recent changes and new versions of Ubuntu
- Create and edit graphics, and work with consumer IoT electronic devices
- Add printers, disks, and other devices to your system
- Configure core network services and administer Ubuntu systems
Ubuntu Linux Bible is a must-have for anyone looking for an accessible, step-by-step tutorial on this hugely popular Linux operating system.
Table of Contents
Acknowledgments ix
Introduction xxix
Part I: Getting Started 1
Chapter 1: Starting with Linux 3
Understanding What Linux is 4
Understanding How Linux Differs from Other Operating Systems 6
Exploring Linux History 7
Free-flowing UNIX culture at Bell Labs 7
Commercial UNIX 9
Berkeley Software Distribution arrives 9
UNIX Laboratory and commercialization 10
GNU transitions UNIX to freedom 11
BSD loses some steam 13
Linus builds the missing piece 13
OSI open source definition 14
Understanding How Linux Distributions Emerged 16
Understanding Red Hat 17
Understanding Ubuntu and other Debian distributions 17
Finding Professional Opportunities with Linux Today 18
Understanding how companies make money with Linux 19
Summary 20
Chapter 2: Creating the Perfect Linux Desktop 21
Understanding Linux Desktop Technology 22
Starting with the GNOME 3 Desktop Live Image 24
Using the GNOME 3 Desktop 25
After the computer boots up 25
Navigating with the mouse 25
Navigating with the keyboard 30
Setting up the GNOME 3 desktop 31
Extending the GNOME 3 desktop 31
Using GNOME shell extensions 32
Using the GNOME Tweak Tool 33
Starting with desktop applications 33
Managing files and folders with Nautilus 33
Installing and managing additional software 35
Playing music with Rhythmbox 37
Stopping the GNOME 3 desktop 37
Using the Unity Graphical Shell with the GNOME Desktop 37
Using the Metacity window manager 38
Changing GNOME’s appearance 40
Using the panels 40
Adding a drawer 41
Changing panel properties 41
Summary 42
Exercises 42
Part II: Becoming a Linux Power User 43
Chapter 3: Using the Shell 45
About Shells and Terminal Windows 46
Using the shell prompt 47
Using a Terminal window 48
Using virtual consoles 49
Choosing Your Shell 49
Running Commands 50
Understanding command syntax 51
Locating commands 53
Recalling Commands Using Command History 56
Command-line editing 56
Command-line completion 58
Command-line recall 59
Connecting and Expanding Commands 61
Piping between commands 62
Sequential commands 62
Background commands 63
Expanding commands 63
Expanding arithmetic expressions 63
Expanding variables 64
Using Shell Variables 64
Creating and using aliases 66
Exiting the shell 67
Creating Your Shell Environment 67
Configuring your shell 67
Setting your prompt 68
Adding environment variables 70
Getting Information about Commands 71
Summary 74
Exercises 74
Chapter 4: Moving Around the Filesystem 77
Using Basic Filesystem Commands 80
Using Metacharacters and Operators 82
Using fi le-matching metacharacters 82
Using fi le-redirection metacharacters 84
Using brace expansion characters 85
Listing Files and Directories 86
Understanding File Permissions and Ownership 90
Changing permissions with chmod (numbers) 91
Changing permissions with chmod (letters) 92
Setting default file permission with umask 93
Changing file ownership 93
Moving, Copying, and Removing Files 94
Summary 95
Exercises 96
Chapter 5: Working with Text Files 97
Editing Files with vim and vi 97
Starting with vi 99
Adding text 99
Moving around in the text 100
Deleting, copying, and changing text 101
Pasting (putting) text 102
Repeating commands 102
Exiting vi 102
Skipping around in the file 103
Searching for text 103
Using ex mode 104
Learning more about vi and vim 104
Finding Files 105
Using locate to find files by name 105
Searching for files with find 107
Finding files by name 108
Finding files by size 108
Finding files by user 109
Finding files by permission 109
Finding files by date and time 110
Using “not” and “or” when finding files 111
Finding files and executing commands 112
Searching in files with grep 113
Summary 115
Exercises 115
Chapter 6: Managing Running Processes 117
Understanding Processes 117
Listing Processes 118
Listing processes with ps 118
Listing and changing processes with top 120
Listing processes with System Monitor 122
Managing Background and Foreground Processes 124
Starting background processes 124
Using foreground and background commands 125
Killing and Renicing Processes 126
Killing processes with kill and killall 126
Using kill to signal processes by PID 127
Using killall to signal processes by name 128
Setting processor priority with nice and renice 128
Limiting Processes with cgroups 129
Summary 131
Exercises 131
Chapter 7: Writing Simple Shell Scripts 133
Understanding Shell Scripts 133
Executing and debugging shell scripts 134
Understanding shell variables 135
Special shell positional parameters 136
Reading in parameters 137
Parameter expansion in bash 137
Performing arithmetic in shell scripts 138
Using programming constructs in shell scripts 139
The “if then” statements 139
The case command 142
The “for do” loop 143
The “while do” and “until do” loops 144
Trying some useful text manipulation programs 145
The global regular expression print 145
Remove sections of lines of text (cut) 145
Translate or delete characters (tr) 146
The stream editor (sed) 146
Using simple shell scripts 147
Telephone list 147
Backup script 148
Summary 149
Exercises 149
Part III: Becoming a Linux System Administrator 151
Chapter 8: Learning System Administration 153
Understanding System Administration 153
Using Graphical Administration Tools 155
Using Cockpit browser-based administration 155
Using other browser-based admin tools 157
Invoking Administration Privileges 158
Becoming root from the shell 158
Gaining temporary admin access with sudo 159
Exploring Administrative Commands, Configuration Files, and Log Files 161
Administrative commands 161
Administrative configuration files 162
Administrative log files and systemd journal 165
Using journalctl to view the systemd journal 165
Managing log messages with rsyslogd 166
Using Other Administrative Accounts 167
Checking and Configuring Hardware 167
Checking your hardware 168
Managing removable hardware 171
Working with loadable modules 172
Listing loaded modules 172
Loading modules 173
Removing modules 174
Summary 174
Exercises 175
Chapter 9: Installing Linux 177
Choosing a Computer 178
Installing Ubuntu Desktop 180
Installing Ubuntu Server 185
Understanding Cloud-Based Installations 188
Installing Linux in the Enterprise 189
Exploring Common Installation Topics 189
Upgrading or installing from scratch 189
Dual booting 190
Installing Linux to run virtually 191
Using installation boot options 192
Boot options for disabling features 192
Boot options for video problems 193
Boot options for special installation types 193
Using specialized storage 194
Partitioning hard drives 195
Understanding different partition types 196
Tips for creating partitions 196
Using the GRUB 2 boot loader 198
Summary 199
Exercises 199
Chapter 10: Getting and Managing Software 201
Managing Software on the Desktop 201
Going Beyond the Software Window 203
Understanding Linux Software Packaging 204
Working with Debian Packaging 205
APT basics 205
Working with APT repositories 209
Working with dpkg 211
Summary 214
Exercises 214
Chapter 11: Managing User Accounts 215
Creating User Accounts 215
Adding users with adduser 218
Setting user defaults 220
Modifying users with usermod 222
Deleting users with deluser 223
Understanding Group Accounts 223
Using group accounts 224
Creating group accounts 225
Managing Users in the Enterprise 225
Setting permissions with Access Control Lists 226
Setting ACLs with setfacl 227
Setting default ACLs 228
Enabling ACLs 229
Adding directories for users to collaborate 231
Creating group collaboration directories (set GID bit) 231
Creating restricted deletion directories (sticky bit) 233
Centralizing User Accounts 233
Summary 234
Exercises 234
Chapter 12: Managing Disks and Filesystems 237
Understanding Disk Storage 237
Partitioning Hard Disks 239
Understanding partition tables 239
Viewing disk partitions 240
Creating a single-partition disk 241
Creating a multiple-partition disk 245
Using Logical Volume Manager Partitions 249
Checking an existing LVM 249
Creating LVM logical volumes 252
Growing LVM logical volumes 254
Mounting Filesystems 254
Supported filesystems 255
Enabling swap areas 257
Disabling swap area 258
Using the fstab file to define mountable filesystems 258
Using the mount command to mount filesystems 261
Mounting a disk image in loopback 262
Using the umount command 262
Using the mkfs Command to Create a Filesystem 263
Managing Storage with Cockpit 264
Summary 265
Exercises 266
Part IV: Becoming a Linux Server Administrator 267
Chapter 13: Understanding Server Administration 269
Getting Started with Server Administration 270
Step 1: Install the server 270
Step 2: Configure the server 272
Using configuration files 272
Checking the default configuration 272
Step 3: Start the server 272
Step 4: Secure the server 274
Password protection 274
Firewalls 274
TCP Wrappers 274
AppArmor 275
Security settings in configuration files 275
Step 5: Monitor the server 275
Configure logging 275
Run system activity reports 276
Watch activity live with Cockpit 276
Keep system software up to date 277
Check the filesystem for signs of crackers 277
Checking and Setting Servers 277
Managing Remote Access with the Secure Shell Service 277
Starting the openssh-server service 278
Using SSH client tools 278
Using ssh for remote login 279
Using SSH for remote execution 280
Copying files between systems with scp and rsync 281
Interactive copying with sftp 284
Using key-based (passwordless) authentication 285
Configuring System Logging 286
Enabling system logging with rsyslog 287
Understanding the rsyslog.conf file 287
Understanding log messages 289
Setting up and using a loghost with rsyslogd 289
Watching logs with logwatch 290
Checking System Resources with sar 291
Checking System Space 293
Displaying system space with df 293
Checking disk usage with du 294
Finding disk consumption with find 294
Managing Servers in the Enterprise 295
Summary 296
Exercises 296
Chapter 14: Administering Networking 299
Configuring Networking for Desktops 300
Checking your network interfaces 302
Checking your network from NetworkManager 302
Checking your network from Cockpit 303
Checking your network from the command line 304
Configuring network interfaces 308
Setting IP addresses manually 308
Setting IP address aliases 309
Setting routes 310
Configuring a network proxy connection 311
Configuring Networking from the Command Line 312
Configure networking with nmtui 312
Editing a NetworkManager TUI connection 313
Understanding networking configuration files 314
Other networking files 315
Setting alias network interfaces 318
Setting up Ethernet channel bonding 319
Setting custom routes 320
Configuring Networking in the Enterprise 321
Configuring Linux as a router 321
Configuring Linux as a DHCP server 322
Configuring Linux as a DNS server 322
Configuring Linux as a proxy server 323
Summary 323
Exercises 324
Chapter 15: Starting and Stopping Services 327
Understanding the Initialization Daemon (init or systemd) 328
Understanding the classic init daemons 329
Understanding systemd initialization 335
Learning systemd basics 335
Learning systemd’s backward compatibility to SysVinit 341
Checking the Status of Services 343
Checking services for SysVinit systems 343
Stopping and Starting Services 346
Stopping and starting SysVinit services 346
Stopping a service with systemd 347
Starting a service with systemd 348
Restarting a service with systemd 348
Reloading a service with systemd 349
Enabling Persistent Services 350
Configuring persistent services for SysVinit 350
Enabling a service with systemd 351
Disabling a service with systemd 352
Configuring a Default Runlevel or Target Unit 353
Configuring the SysVinit default runlevel 353
Adding New or Customized Services 354
Adding new services to SysVinit 355
Step 1: Create a new or customized service script file 355
Step 2: Add the service script to /etc/rc.d/init.d 356
Step 3: Set appropriate permission on the script 357
Step 4: Add the service to runlevel directories 357
Adding new services to systemd 357
Step 1: Create a new or customized service configuration unit file 358
Step 2: Move the service configuration unit file 358
Step 3: Add the service to the Wants directory 359
Summary 360
Exercises 360
Chapter 16: Configuring a Print Server 363
Common UNIX Printing System 363
Setting Up Printers 365
Adding a printer automatically 365
Using web-based CUPS administration 366
Allow remote printing administration 367
Add a printer not automatically detected 367
Using the Print Settings window 368
Configuring local printers with the Print Settings window 369
Configuring remote printers 372
Adding a remote CUPS printer 373
Adding a remote UNIX (LDP/LPR) printer 373
Adding a Windows (SMB) printer 374
Working with CUPS Printing 375
Configuring the CUPS server (cupsd.conf) 375
Starting the CUPS server 376
Configuring CUPS printer options manually 377
Using Printing Commands 378
Printing with lp 378
Listing status with lpstat -t 379
Removing print jobs with cancel 379
Configuring Print Servers 380
Configuring a shared CUPS printer 380
Configuring a shared Samba printer 381
Understanding smb.conf for printing 382
Setting up SMB clients 382
Summary 383
Exercises 383
Chapter 17: Configuring a Web Server r 385
Understanding the Apache Web Server 385
Getting and Installing Your Apache Web Server 386
Controlling Apache 389
Securing Apache 389
Apache file permissions and ownership 389
Apache and firewalls 390
Apache and AppArmor 390
Understanding the Apache configuration files 393
Using directives 393
Understanding default settings 395
Adding a virtual host to Apache 398
Allowing users to publish their own web content 400
Securing your web traffic with TLS 401
Understanding how SSL is configured 402
Generating an SSL key and self-signed certificate 403
Generating a certificate signing request 405
Troubleshooting Your Web Server 406
Checking for configuration errors 406
Access forbidden and server internal errors 408
Summary 410
Exercises 410
Chapter 18: Configuring an FTP Server 413
Understanding FTP 413
Installing the vsftpd FTP Server 415
Controlling the vsftpd Service 416
Securing your FTP server 417
Integrating Linux file permissions with vsftpd 418
Configuring Your FTP Server 418
Setting up user access 418
Allowing uploading 419
Setting up vsftpd for the Internet 420
Using FTP Clients to Connect to Your Server 422
Accessing an FTP server from a browser 422
Accessing an FTP server with the lftp command 423
Using the gFTP client 425
Summary 426
Exercises 426
Chapter 19: Configuring a Windows File Sharing (Samba) Server r 429
Understanding Samba 429
Installing Samba 430
Controlling Samba 431
Viewing Samba processes 431
Configuring Samba 435
Configuring the [global] section 435
Configuring the [homes] section 437
Configuring the [printers] section 437
Creating a Samba shared folder 438
Checking the Samba share 438
Accessing Samba Shares 441
Accessing Samba shares in Linux 442
Accessing Samba shares from a Linux file manager 442
Mounting a Samba share from a Linux command line 442
Accessing Samba shares in Windows 444
Using Samba in the Enterprise 444
Summary 444
Exercises 445
Chapter 20: Configuring an NFS File Server 447
Installing an NFS Server 448
Starting the NFS Service 449
Sharing NFS Filesystems 450
Configuring the /etc/exports file 450
Hostnames in /etc/exports 451
Access options in /etc/exports 452
User mapping options in /etc/exports 453
Exporting the shared filesystems 454
Securing Your NFS Server 454
Using NFS Filesystems 455
Viewing NFS shares 456
Manually mounting an NFS filesystem 456
Mounting an NFS filesystem at boot time 457
Mounting noauto filesystems 458
Using mount options 458
Using autofs to mount NFS filesystems on demand 460
Automounting to the /net directory 460
Automounting home directories 461
Unmounting NFS Filesystems 463
Summary 464
Exercises 464
Chapter 21: Troubleshooting Linux 467
Boot-Up Troubleshooting 467
Understanding startup 468
Starting from the firmware (BIOS or UEFI) 469
Troubleshooting BIOS setup 470
Troubleshooting boot order 471
GRUB 2 boot loader 471
Starting the kernel 472
Troubleshooting the initialization system 474
Troubleshooting Software Packages 476
Troubleshooting Networking 479
Troubleshooting outgoing connections 479
View network interfaces 480
Check physical connections 480
Check routes 481
Check hostname resolution 482
Troubleshooting incoming connections 483
Check if the client can reach your system at all 483
Check if the service is available to the client 484
Check the service on the server 485
Troubleshooting Memory 485
Uncovering memory issues 486
Checking for memory problems 488
Dealing with memory problems 489
Summary 490
Exercises 490
Part V: Learning Linux Security Techniques 493
Chapter 22: Understanding Basic Linux Security y 495
Implementing Physical Security 495
Implementing disaster recovery 496
Securing user accounts 496
One user per user account 497
Limiting access to the root user account 497
Setting expiration dates on temporary accounts 497
Removing unused user accounts 498
Securing passwords 500
Choosing good passwords 500
Setting and changing passwords 501
Enforcing best password practices 502
Understanding the password files and password hashes 504
Securing the filesystem 506
Managing dangerous filesystem permissions 506
Securing the password files 507
Locking down the filesystem 508
Managing software and services 509
Updating software packages 509
Keeping up with security advisories 509
Advanced implementation 510
Monitoring Your Systems 510
Monitoring log files 510
Monitoring user accounts 512
Detecting counterfeit accounts and privileges 512
Detecting bad account passwords 514
Monitoring the filesystem 516
Verifying software packages 516
Scanning the filesystem 516
Detecting viruses and rootkits 518
Auditing and Reviewing Linux 521
Conducting compliance reviews 521
Conducting security reviews 522
Summary 522
Exercises 523
Chapter 23: Understanding Advanced Linux Security y 525
Implementing Linux Security with Cryptography 525
Understanding hashing 526
Understanding encryption/decryption 527
Understanding cryptographic ciphers 527
Understanding cryptographic cipher keys 527
Understanding digital signatures 533
Implementing Linux cryptography 535
Ensuring file integrity 535
Encrypting a Linux filesystem at installation 536
Encrypting a Linux directory 537
Encrypting a Linux file 540
Encrypting Linux with miscellaneous tools 540
Using Encryption from the Desktop 541
Implementing Linux Security with PAM 541
Understanding the PAM authentication process 542
Understanding PAM contexts 543
Understanding PAM control flags 544
Understanding PAM modules 545
Understanding PAM system event configuration files 545
Administering PAM on your Linux system 546
Managing PAM-aware application configuration files 546
Implementing resources limits with PAM 547
Implementing time restrictions with PAM 549
Enforcing good passwords with PAM 550
Encouraging sudo use with PAM 551
Obtaining more information on PAM 551
Summary 552
Exercises 552
Chapter 24: Enhancing Linux Security with AppArmor 553
Understanding AppArmor 553
Working with AppArmor 556
Summary 559
Exercises 560
Chapter 25: Securing Linux on a Network 561
Auditing Network Services 561
Evaluating access to network services with nmap 563
Using nmap to audit your network services’ advertisements 566
Working with Firewalls 570
Understanding firewalls 571
Implementing firewalls 572
Starting with UFW 572
Understanding the iptables utility 574
Using the iptables utility 576
Summary 583
Exercises 583
Part VI: Engaging with Cloud Computing 585
Chapter 26: Shifting to Clouds and Containers 587
Understanding Linux Containers 588
Namespaces 589
Container registries 589
Base images and layers 590
Working with Linux Containers 590
Deploying LXD containers 590
Deploying Docker containers 593
Using containers in the enterprise 600
Summary 600
Exercises 600
Chapter 27: Deploying Linux to the Public Cloud 601
Running Linux in the Cloud Using cloud-init 601
Creating LXD Linux Images for Cloud Deployments 604
Working with LXD profiles 604
Working with LXD images 607
Using OpenStack to deploy cloud images 608
Using Amazon EC2 to Deploy Cloud Images 610
Installing the AWS CLI 611
Provisioning and launching an EC2 instance 613
Summary 618
Exercises 618
Chapter 28: Automating Apps and Infrastructure with Ansible 619
Understanding Ansible 620
Exploring Ansible Components 621
Inventories 621
Playbooks 622
Plays 622
Tasks 622
Modules 622
Roles, imports, and includes 623
Stepping Through an Ansible Deployment 623
Prerequisites 624
Setting up SSH keys to each node 624
Installing Ansible 626
Creating an inventory 626
Authenticating to the hosts 626
Creating a playbook 627
Run the playbook 628
Running Ad-Hoc Ansible Commands 629
Trying ad-hoc commands 629
Summary 631
Exercises 631
Chapter 29 Deploying Applications as Containers with Kubernetes 633
Understanding Kubernetes 634
Kubernetes masters 634
Kubernetes workers 635
Kubernetes applications 635
Kubernetes interfaces 636
Trying Kubernetes 636
Getting Kubernetes up and running 637
Deploying a Kubernetes application 638
Getting information on the deployment’s pods 639
Exposing applications with services 643
Scaling up an application 644
Checking the load balancer 645
Scaling down an application 646
Deleting a service 646
Summary 647
Exercises 647
Appendix: Exercise Answers 649
Index 701
