Red Hat Enterprise Linux 8 Administration: Master Linux administration skills and prepare for the RHCSA certification exam

Description

Develop the skill to manage and administer Red Hat Enterprise Linux and get ready to achieve the RHCSA certification Key FeaturesLearn the most common administration and security tasks and manage enterprise Linux infrastructures efficientlyAssess your knowledge using self-assessment questions based on real-world examplesUnderstand how to apply the concepts of core systems administration in the real worldBook Description Whether in infrastructure or development, as a DevOps or site reliability engineer, Linux skills are now more relevant than ever for any IT job, forming the foundation of understanding the most basic layer of your architecture. With Red Hat Enterprise Linux (RHEL) becoming the most popular choice for enterprises worldwide, achieving the Red Hat Certified System Administrator (RHCSA) certification will validate your Linux skills to install, configure, and troubleshoot applications and services on RHEL systems. Complete with easy-to-follow tutorial-style content, self-assessment questions, tips, best practices, and practical exercises with detailed solutions, this book covers essential RHEL commands, user and group management, software management, networking fundamentals, and much more. You'll start by learning how to create an RHEL 8 virtual machine and get to grips with essential Linux commands. You'll then understand how to manage users and groups on an RHEL 8 system, install software packages, and configure your network interfaces and firewall. As you advance, the book will help you explore disk partitioning, LVM configuration, Stratis volumes, disk compression with VDO, and container management with Podman, Buildah, and Skopeo. By the end of this book, you'll have covered everything included in the RHCSA EX200 certification and be able to use this book as a handy, on-the-job desktop reference guide. This book and its contents are solely the work of Miguel Pérez Colino, Pablo Iranzo Gómez, and Scott McCarty. The content does not reflect the views of their employer (Red Hat Inc.). This work has no connection to Red Hat, Inc. and is not endorsed or supported by Red Hat, Inc. What you will learnDeploy RHEL 8 in different footprints, from bare metal and virtualized to the cloudManage users and software on local and remote systems at scaleDiscover how to secure a system with SELinux, OpenSCAP, and firewalldGain an overview of storage components with LVM, Stratis, and VDOMaster remote administration with passwordless SSH and tunnelsMonitor your systems for resource usage and take actions to fix issuesUnderstand the boot process, performance optimizations, and containersWho this book is for This book is for IT professionals or students who want to start a career in Linux administration and anyone who wants to take the RHCSA 8 certification exam. Basic knowledge of Linux and familiarity with the Linux command-line is necessary. Table of ContentsInstalling RHEL8RHEL8 Advanced Installation OptionsBasic Commands and Simple Shell ScriptsTools for Regular OperationsSecuring Systems with Users, Groups, and PermissionsEnabling Network ConnectivityAdding, Patching, and Managing SoftwareAdministering Systems RemotelySecuring Network Connectivity with firewalldKeeping Your System Hardened with SELinuxSystem Security Profiles with OpenSCAPManaging Local Storage and FilesystemsFlexible Storage Management with LVMAdvanced Storage Management with Stratis and VDOUnderstanding the Boot Process (N.B. Please use the Look Inside option to see further chapters) Cover Title Page Copyright and Credits Dedicated Contributors Table of Contents Preface Section 1: Systems Administration – Software, User, Network, and Services Management Chapter 1: Installing RHEL8 Technical requirements Obtaining RHEL software and a subscription Installing RHEL8 Preparation for a physical server installation Preparation for a virtual server installation Running an RHEL installation Summary Chapter 2: RHEL8 Advanced Installation Options Technical requirements Automating RHEL deployments with Anaconda Deploying RHEL on the cloud Installation best practices Summary Chapter 3: Basic Commands and Simple Shell Scripts Logging in as a user and managing multi-user environments Using the root account Using and understanding the command prompt Changing users with the su command Understanding users, groups, and basic permissions Users Groups File permissions Using the command line, environment variables, and navigating through the filesystem Command line and environment variables Navigating the filesystem Bash autocomplete Filesystem hierarchy Understanding I/O redirection in the command line Filtering output with grep and sed Listing, creating, copying, and moving files and directories, links, and hard links Directories Copying and moving Symbolic and hard links Using tar and gzip Creating basic shell scripts for loops if conditionals Exit codes Using system documentation resources Man pages Info pages Other documentation resources Summary Chapter 4: Tools for Regular Operations Technical requirements Managing system services with systemd Systemd unit file structure Managing services to be started and stopped at boot Managing boot targets Scheduling tasks with cron and systemd System-wide crontab User crontab Systemd timers Learning about time synchronization with chrony and NTP NTP client NTP server Checking for free resources – memory and disk (free and df) Memory Disk space CPU Load average Other monitoring tools Finding logs, using journald, and reading log files, including log preservation and rotation Log rotation Summary Chapter 5: Securing Systems with Users, Groups, and Permissions Creating, modifying, and deleting local user accounts and groups Managing groups and reviewing assignments Adjusting password policies Configuring sudo access for administrative tasks Understanding sudo configuration Using sudo to run admin commands Configuring sudoers Checking, reviewing, and modifying file permissions Using special permissions Understanding and applying Set-UID Understanding and applying Set-GID Using the sticky bit Summary Chapter 6: Enabling Network Connectivity Technical requirements Exploring network configuration in RHEL Getting to know the configuration files and NetworkManager Configuring network interfaces with IPv4 and IPv6 IPv4 and IPv6... what does that mean? Configuring interfaces with nmtui Configuring interfaces with nm-connection-editor Configuring interfaces with nmcli Configuring interfaces with text files Configuring hostname and hostname resolutions (DNS) Overview of firewall configuration Configuring the firewall Testing network connectivity Summary Chapter 7: Adding, Patching, and Managing Software RHEL subscription registration and management Managing repositories and signatures with YUM/DNF Doing software installations, updates, and rollbacks with YUM/DNF Creating and syncing repositories with createrepo and reposync Understanding RPM internals Summary Section 2: Security with SSH, SELinux, a Firewall, and System Permissions Chapter 8: Administering Systems Remotely Technical requirements SSH and OpenSSH overview and base configuration OpenSSH server OpenSSH client Accessing remote systems with SSH Key-based authentication with SSH SSH agent SCP/rsync – remote file management Transferring files with an OpenSSH secure file copy Transferring files with sftp Transferring files with rsync Advanced remote management – SSH tunnels and SSH redirections Remote terminals with tmux Summary Chapter 9: Securing Network Connectivity with firewalld Introduction to the RHEL firewall – firewalld Enabling firewalld in the system and reviewing the default zones Reviewing the different configuration items under firewalld Enabling and managing services and ports Creating and using service definitions for firewalld Configuring firewalld with the web interface Summary Chapter 10: Keeping Your System Hardened with SELinux Technical requirements SELinux usage in enforcing and permissive modes Reviewing the SELinux context for files and processes Tweaking the policy with semanage Restoring changed file contexts to the default policy Using SELinux Boolean settings to enable services SELinux troubleshooting and common fixes Summary Chapter 11: System Security Profiles with OpenSCAP Getting started with OpenSCAP and discovering system vulnerabilities Using OpenSCAP with security profiles for OSPP and PCI DSS Scanning for OSPP compliance Scanning for PCI DSS compliance Summary Section 3: Resource Administration – Storage, Boot Process, Tuning, and Containers Chapter 12: Managing Local Storage and Filesystems Technical requirements Let's start with a definition A bit of history Partitioning disks (MBR and GPT disks) Formatting and mounting filesystems Setting default mounts and options in fstab Using network filesystems with NFS Summary Chapter 13: Flexible Storage Management with LVM Technical requirements Understanding LVM Creating, moving, and removing physical volumes Combining physical volumes into volume groups Creating and extending logical volumes Adding new disks to a volume group and extending a logical volume Removing logical volumes, volume groups, and physical volumes Reviewing LVM commands Summary Chapter 14: Advanced Storage Management with Stratis and VDO Technical requirements Understanding Stratis Installing and enabling Stratis Managing storage pools and filesystems with Stratis Preparing systems to use VDO Creating a VDO volume Assigning a VDO volume to an LVM volume Testing a VDO volume and reviewing the stats Summary Chapter 15: Understanding the Boot Process Understanding the boot process – BIOS and UEFI booting Working with GRUB, the bootloader, and initrd system images Managing the boot sequence with systemd Intervening in the boot process to gain access to a system Summary Chapter 16: Kernel Tuning and Managing Performance Profiles with tuned Technical requirements Identifying processes, checking memory usage, and killing processes Adjusting kernel scheduling parameters to better manage processes Installing tuned and managing tuning profiles Creating a custom tuned profile Summary Chapter 17: Managing Containers with Podman, Buildah, and Skopeo Technical requirements Introduction to containers Installing container tools Running a container using Podman and UBI Basic container management – pull, run, stop, and remove Attaching persistent storage to a container Deploying a container on a production system with systemd Building a container image using a Dockerfile or Containerfile Configuring Podman to search registry servers Summary of Podman options When to use Buildah and Skopeo Building container images with Buildah Inspecting a remote container with Skopeo Summary Section 4: Practical Exercises Chapter 18: Practice Exercises – 1 Technical requirements Tips for the exercise Practice exercise 1 Exercise 1 resolution Chapter 19: Practice Exercise – 2 Technical requirements Tips for the exercise Practice exercise – 2 Answers to practice exercise 2 About Packt Other Books You May Enjoy Index