,Introduction
The Power of Linux
When my mother gave me a cast-off x386 IBM-clone computer in the mid-1990s, I wasn’t
entirely sure what I was going to do with it, but I felt impelled to get it running. My biggest
challenge in doing so was economic, not technical. I was too cheap to buy a licensed copy of
Windows 3.1 and went hunting for an alternative. Fortunately, I came across a book
titled Linux Installation & Getting Started by Matt Welsh, which showed me everything I
needed to get started. I downloaded the Slackware Linux installation files over a 56k modem,
wrote them to a stack of floppy disks, and literally gave an audible hoot when I got the system
up and running.
The moment markedly changed my future, with Linux and open source software becoming
a key part of my life, first as a hobby and ultimately as a career.
Other early Linux adopters have similar stories to tell, and like them, I was fascinated by the
ability to freely download and install a complete operating system and do “real computing.”
In the ensuing years, I bought my share of thick Linux texts, installed hundreds (perhaps
thousands) of Linux systems, and learned how to use and rely on open source software. That
experience is encapsulated in this book.
A lot has changed in the technology world in the 30-plus years since Linus Torvalds first
released Linux (and the hard-working kernel) in 1991, and much has been written about it.
It’s no accident that Linux and the Internet grew up together. Linux remains a critical
component of the technical landscape, spawning whole industries and many well-paying
jobs. It’s at the core of modern life, though few recognize that fact. Today’s software
developers certainly have heard of it, but many have never had a chance to really explore it.
Practical Linux DevOps is written to be a go-to Linux book for IT practitioners—or those who
want to be—who want to explore Linux and the technologies that make modern software
happen. It provides real-world tutorials and examples centered around DevOps practices,
the concept of continuously building, testing, and deploying software applications that
bridge the development side (think software and security engineers) and operations (think
hardware administrators). DevOps is how modern software is made, and Linux is in the
midst of it all. This book seeks to teach you practical Linux concepts within the context of
DevOps, giving you the knowledge you need to confidently continue your exploration.
Learning to Fish
The chapters in this book represent the culmination of my experience with Linux and open
source software with new users in mind. I attempt to explain concepts in terms anyone can
understand, and provide enough context to explain the whys, not just the hows. I want to
leave you wanting more and with the ability to reason out how to keep learning. The adage
goes, “If you give a man a fish, you feed him for a day. If you teach a man to fish, you feed him
,for a lifetime.” The goal of Practical Linux DevOps is to teach you how to fish (and not fear the
command line).
Where can Linux take you? With Linux running on NASA’s Perseverance rover that’s
exploring Mars, the sky is no longer the limit. This book will help you become part of it all.
Tips for Setting Up Your Environment
Your Workstation
This book presumes you’ll use a Linux workstation for all the work you do, not just the virtual
machines and containers you create. As you’ll read in Chapter 1, you can make good use of
older hardware for a Linux workstation. The examples in this book mostly use Ubuntu (based
on Debian), and there are many flavors of Ubuntu and other Linux distributions that can run
on older Windows and Macintosh computers. I recommend using an existing spare machine,
but if money is no object, feel free to get a new or used Intel- or AMD-based machine and
install Linux on it.
Environment Settings
After installing a fresh Linux desktop, there are a few steps I always take to make the
workstation environment comfortable to my way of working. For example, when you run
commands as a superuser (something you’ll do all the time), sudo requires a password.
When you’re running dozens or hundreds of sudo commands a day, this can become tiring.
I solve that problem by creating a file in /etc/sudoers.d/ that gives me superuser
privileges without requiring a password.
To do this, create a new file in /etc/sudoers.d and add the following line,
replacing <username> with the username you use on your Linux system:
$ sudo vi /etc/sudoers.d/<username>
<username> ALL=(ALL) NOPASSWD:ALL
After you save this file, you’ll be able to run sudo commands without entering a password.
Of course, this isn’t exactly secure and shouldn’t automatically be added to production
systems, but when you’re working on your Linux workstation, it saves a lot of time and
hassle.
Terminal Look and Feel
You’ll spend a lot of time in your Linux terminal, so take a moment to make it comfortable.
There’s no need to squint at tiny text or colors you don’t like. Xterm and other modern Linux
terminals allow you to easily adjust the font, font size, text colors, and background. I
recommend editing the preferences to make your terminal suit your tastes.
Power Settings
, It might seem like a little thing, but I hate when my workstation screen goes to sleep too
often. By default, many Linux desktops go to sleep after just five minutes. You might look
away for a few minutes to check headlines or focus on another machine, and you’ll have to
log back in. I recommend going into your system’s Power settings to adjust the screen
timeout to at least 30 minutes.
Multiple Computers, One Mouse and Keyboard
If you’re running your Linux machine alongside another separate workstation, such as
Windows or Macintosh, it can be quite cumbersome to have two different keyboards and
mice. I resolve this by using a little tool called Barrier, a fork of Synergy, that allows you to
share your mouse and keyboard with multiple systems on the same network. The machine
with your physical keyboard and mouse attached becomes the Barrier server; every other
machine becomes a Barrier client. You can set the geometry (left, right, up, or down) relative
to your server machine and seamlessly control, copy, and paste (but not drag and drop) many
different Linux, Windows, and Macintosh computers with a single keyboard and mouse.
SCP
There are times when you need to move files from one Linux machine to another. You can
email them to yourself, but I’ve found the tool SCP to be the best way to move files. It uses
SSH to copy files or folders from one system to another. There’s no need to use FTP or other
means:
$ scp /path/to/local_file username@remote_host:/path/to/remote_file
You can copy whole directories using SCP by adding the -r (recursive) flag:
$ scp -r /path/to/local_folder username@remote_host:/path/to/remote_folder
Set Up Passwordless SSH
When you’re regularly SSHing or SCPing between machines, it can save a lot of time if you
set up SSH keys between them. This enables you to use ssh and scp without having to
always enter a password.
To set this up, start by creating an SSH key on your workstation:
$ ssh-keygen
Follow the prompts, but do not provide a password for the key. Then copy the newly
generated key to one or more target systems:
$ ssh-copy-id username@remote_host
You’ll be prompted to enter a password when you first use ssh-copy-id to copy the key,
but never again after that. This simple setup makes for a more seamless integration between
multiple Linux (and Macintosh) machines.
Enjoy the Ride
The Power of Linux
When my mother gave me a cast-off x386 IBM-clone computer in the mid-1990s, I wasn’t
entirely sure what I was going to do with it, but I felt impelled to get it running. My biggest
challenge in doing so was economic, not technical. I was too cheap to buy a licensed copy of
Windows 3.1 and went hunting for an alternative. Fortunately, I came across a book
titled Linux Installation & Getting Started by Matt Welsh, which showed me everything I
needed to get started. I downloaded the Slackware Linux installation files over a 56k modem,
wrote them to a stack of floppy disks, and literally gave an audible hoot when I got the system
up and running.
The moment markedly changed my future, with Linux and open source software becoming
a key part of my life, first as a hobby and ultimately as a career.
Other early Linux adopters have similar stories to tell, and like them, I was fascinated by the
ability to freely download and install a complete operating system and do “real computing.”
In the ensuing years, I bought my share of thick Linux texts, installed hundreds (perhaps
thousands) of Linux systems, and learned how to use and rely on open source software. That
experience is encapsulated in this book.
A lot has changed in the technology world in the 30-plus years since Linus Torvalds first
released Linux (and the hard-working kernel) in 1991, and much has been written about it.
It’s no accident that Linux and the Internet grew up together. Linux remains a critical
component of the technical landscape, spawning whole industries and many well-paying
jobs. It’s at the core of modern life, though few recognize that fact. Today’s software
developers certainly have heard of it, but many have never had a chance to really explore it.
Practical Linux DevOps is written to be a go-to Linux book for IT practitioners—or those who
want to be—who want to explore Linux and the technologies that make modern software
happen. It provides real-world tutorials and examples centered around DevOps practices,
the concept of continuously building, testing, and deploying software applications that
bridge the development side (think software and security engineers) and operations (think
hardware administrators). DevOps is how modern software is made, and Linux is in the
midst of it all. This book seeks to teach you practical Linux concepts within the context of
DevOps, giving you the knowledge you need to confidently continue your exploration.
Learning to Fish
The chapters in this book represent the culmination of my experience with Linux and open
source software with new users in mind. I attempt to explain concepts in terms anyone can
understand, and provide enough context to explain the whys, not just the hows. I want to
leave you wanting more and with the ability to reason out how to keep learning. The adage
goes, “If you give a man a fish, you feed him for a day. If you teach a man to fish, you feed him
,for a lifetime.” The goal of Practical Linux DevOps is to teach you how to fish (and not fear the
command line).
Where can Linux take you? With Linux running on NASA’s Perseverance rover that’s
exploring Mars, the sky is no longer the limit. This book will help you become part of it all.
Tips for Setting Up Your Environment
Your Workstation
This book presumes you’ll use a Linux workstation for all the work you do, not just the virtual
machines and containers you create. As you’ll read in Chapter 1, you can make good use of
older hardware for a Linux workstation. The examples in this book mostly use Ubuntu (based
on Debian), and there are many flavors of Ubuntu and other Linux distributions that can run
on older Windows and Macintosh computers. I recommend using an existing spare machine,
but if money is no object, feel free to get a new or used Intel- or AMD-based machine and
install Linux on it.
Environment Settings
After installing a fresh Linux desktop, there are a few steps I always take to make the
workstation environment comfortable to my way of working. For example, when you run
commands as a superuser (something you’ll do all the time), sudo requires a password.
When you’re running dozens or hundreds of sudo commands a day, this can become tiring.
I solve that problem by creating a file in /etc/sudoers.d/ that gives me superuser
privileges without requiring a password.
To do this, create a new file in /etc/sudoers.d and add the following line,
replacing <username> with the username you use on your Linux system:
$ sudo vi /etc/sudoers.d/<username>
<username> ALL=(ALL) NOPASSWD:ALL
After you save this file, you’ll be able to run sudo commands without entering a password.
Of course, this isn’t exactly secure and shouldn’t automatically be added to production
systems, but when you’re working on your Linux workstation, it saves a lot of time and
hassle.
Terminal Look and Feel
You’ll spend a lot of time in your Linux terminal, so take a moment to make it comfortable.
There’s no need to squint at tiny text or colors you don’t like. Xterm and other modern Linux
terminals allow you to easily adjust the font, font size, text colors, and background. I
recommend editing the preferences to make your terminal suit your tastes.
Power Settings
, It might seem like a little thing, but I hate when my workstation screen goes to sleep too
often. By default, many Linux desktops go to sleep after just five minutes. You might look
away for a few minutes to check headlines or focus on another machine, and you’ll have to
log back in. I recommend going into your system’s Power settings to adjust the screen
timeout to at least 30 minutes.
Multiple Computers, One Mouse and Keyboard
If you’re running your Linux machine alongside another separate workstation, such as
Windows or Macintosh, it can be quite cumbersome to have two different keyboards and
mice. I resolve this by using a little tool called Barrier, a fork of Synergy, that allows you to
share your mouse and keyboard with multiple systems on the same network. The machine
with your physical keyboard and mouse attached becomes the Barrier server; every other
machine becomes a Barrier client. You can set the geometry (left, right, up, or down) relative
to your server machine and seamlessly control, copy, and paste (but not drag and drop) many
different Linux, Windows, and Macintosh computers with a single keyboard and mouse.
SCP
There are times when you need to move files from one Linux machine to another. You can
email them to yourself, but I’ve found the tool SCP to be the best way to move files. It uses
SSH to copy files or folders from one system to another. There’s no need to use FTP or other
means:
$ scp /path/to/local_file username@remote_host:/path/to/remote_file
You can copy whole directories using SCP by adding the -r (recursive) flag:
$ scp -r /path/to/local_folder username@remote_host:/path/to/remote_folder
Set Up Passwordless SSH
When you’re regularly SSHing or SCPing between machines, it can save a lot of time if you
set up SSH keys between them. This enables you to use ssh and scp without having to
always enter a password.
To set this up, start by creating an SSH key on your workstation:
$ ssh-keygen
Follow the prompts, but do not provide a password for the key. Then copy the newly
generated key to one or more target systems:
$ ssh-copy-id username@remote_host
You’ll be prompted to enter a password when you first use ssh-copy-id to copy the key,
but never again after that. This simple setup makes for a more seamless integration between
multiple Linux (and Macintosh) machines.
Enjoy the Ride
