Preface

Enterprise Linux stands out as the premier choice for organizations seeking a robust, secure, and reliable operating system. In the realm of Linux distributions, Enterprise Linux, exemplified by distributions such as Oracle Linux and Rocky Linux, has earned its reputation as the go-to solution for businesses worldwide. This book explores the key reasons why Oracle Linux is considered the best distribution for enterprise environments and explores several technologies, including Oracle’s distribution, through a series of easy-to-follow, step-by-step examples called recipes. These recipes will teach you how to use technologies in several key areas.

Security is paramount in enterprise environments, and Oracle Linux has set the standard for robust security features. Features such as Security-Enhanced Linux (SELinux), mandatory access control, and a proactive security patching system for no-downtime patching contribute to creating a secure environment. Regular security audits and prompt zero-downtime patching help mitigate vulnerabilities, making Oracle Linux a trusted choice for handling sensitive and mission-critical data.

Enterprise Linux distributions are designed to scale seamlessly, whether on a single server or in a large-scale, clustered environment. The performance optimizations integrated into these distributions ensure that they can handle the demands of modern enterprise applications. Oracle Linux is the leader in performance, with the option to use the Oracle Unbreakable Enterprise Kernel (UEK). This book covers how to install this option and shows several of the key features it brings to the table, such as the Btrfs filesystem. We also cover availability, with more easy-to-follow recipes that cover highly available storage and application clustering.

Oracle Linux benefits from a vast ecosystem of software and applications that are certified and optimized for compatibility. This ecosystem includes database management systems, development tools, middleware, and enterprise applications, making it easier for organizations to build, deploy, and manage their software stacks. This book highlights some of these technologies that support DevOps and DevSecOps teams, such as Ansible and Podman.

Oracle Linux stands tall as the best distribution for enterprise environments due to its rock-solid stability, robust security features, scalability, comprehensive support, compliance with industry standards, and a rich ecosystem. Whether managing critical workloads, securing sensitive data, or ensuring high-performance computing, Enterprise Linux continues to be the top choice for organizations aiming for a reliable and secure operating system.

Who this book is for

This book is for Enterprise Linux admins, specifically admins that manage Oracle Enterprise Linux. Whether you are migrating from CentOS or building a new system, this book is full of useful tricks and tips. The author’s goal is to help you be a more productive admin, adding new technologies to your bag of tricks to make you stand out from the rest.

This book is for Linux system administrators and developers of applications that run on Oracle Linux 8, so you should have a basic understanding of Linux administration and be comfortable with editing configuration files.

What this book covers

Chapter 1, Oracle Linux 8 – Get It? Got It? Good!, covers how you can get Oracle Linux, upgrade Oracle Linux versions, and run them on ARM systems and the cloud!

Chapter 2, Installing with and without Automation Magic, is where we will automate the installation of Oracle Linux with PXE and kickstart the process.

Chapter 3, Exploring the Various Boot Options and Kernels in Oracle Linux, explores what a kernel is and how UEK is different.

Chapter 4, Creating and Managing Single-Instance Filesystems, provides tricks and tips to better manage Btrfs, xfs, and RAID.

Chapter 5, Software Management with DNF, we will look at how to build local reops, make custom RPMs, and better leverage DNF.

Chapter 6, Eliminate All the SPOFs! An Exercise in Redundancy, covers eliminating single points of failure through load balancing, proxies, clusters, cluster filesystems, and network redundancy options.

Chapter 7, Oracle Linux 8 – Patching Doesn’t Have to Mean Rebooting, covers how to patch without rebooting. We will also look at what Ksplice is and why you should be using it.

Chapter 8, DevOps Automation Tools – Terraform, Ansible, Packer, and More, looks at automating the management with Terraform, Vagrant, and Packer.

Chapter 9, Keeping the Data Safe – Securing a System, looks at how to keep out of the news by securing your systems. We will cover encrypting your data, using SELinux, scanning systems for vulnerabilities, and managing GPG keys for signing things.

Chapter 10, Revisiting Modules and AppStreams, looks at how AppStreams has changed software deployment and modernizing application deployments.

Chapter 11, Lions, Tigers, and Containers – Oh My! Podman and Friends, looks at what Podman is, how to use it as a Docker replacement, and how to use Podman, Buildah, and Skopeo to facilitate all your containerized needs.

Chapter 12, Navigating Ansible Waters, covers everything Ansible, from deploying Ansible at the enterprise level with Oracle Linux Automation Manager (OLAM) to writing playbooks.

Chapter 13, Let’s All Go to the Cloud, moves us to the cloud, where we will look at building custom images for AWS and OCI, as well as how to build new VMs in the cloud.

To get the most out of this book

Many of the recipes in this book can be carried out on your desktop system, leveraging Oracle VM VirtualBox to run some complex systems as VMs. We are assuming you are familiar with the basic Linux installation process and admin skills such as becoming the root user.

Software/hardware covered in the book	OS requirements
Oracle Linux 8	Oracle Linux 8

Many of these recipes assume you are the root user, and most admin tasks require this access.

If you are using the digital version of this book, we advise you to type the code yourself or access the code via the GitHub repository (link available in the next section). Doing so will help you avoid any potential errors related to the copying and pasting of code.

Download the example code files

You can download the example code files for this book from GitHub at https://github.com/PacktPublishing/Oracle-Linux-Cookbook. In case there’s an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: “Using the .efi file gives a user more control of the boot process, including the ability to take advantage of new security features.”

A block of code is set as follows:

[ req ]
default_bits = 4096
distinguished_name = req_distinguished_name
prompt = no
string_mask = utf8only
x509_extensions = extensions

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

    </Directory>
    RewriteEngine On
    RewriteCond %{REQUEST_URI} !^/.well-known/acme-challenge [NC]
    RewriteCond %{HTTPS} off
    RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
</VirtualHost>

Any command-line input or output is written as follows:

[root@ol8 # grubby --info=/boot/vmlinuz-0-rescue-c32316cc4b5241b8adb312707ae46458

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: “Select Enroll MOK from the menu.”

Tips or important notes

Appear like this.

Sections

In this book, you will find several headings that appear frequently (Getting ready, How to do it..., How it works..., There’s more..., and See also).

To give clear instructions on how to complete a recipe, use these sections as follows:

Getting ready

This section tells you what to expect in the recipe and describes how to set up any software or any preliminary settings required for the recipe.

How to do it…

This section contains the steps required to follow the recipe.

How it works…

This section usually consists of a detailed explanation of what happened in the previous section.

There’s more…

This section consists of additional information about the recipe in order to make you more knowledgeable about the recipe.

See also

This section provides helpful links to other useful information for the recipe.

Get in touch

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