Book Image

Linux for System Administrators

By : Viorel Rudareanu, Daniil Baturin
Book Image

Linux for System Administrators

By: Viorel Rudareanu, Daniil Baturin

Overview of this book

Linux system administration is an essential aspect of maintaining and managing Linux servers within an organization. The role of a Linux system administrator is pivotal in ensuring the smooth functioning and security of these servers, making it a critical job function for any company that relies on Linux infrastructure. This book is a comprehensive guide designed to help you build a solid foundation in Linux system administration. It takes you from the fundamentals of Linux to more advanced topics, encompassing key areas such as Linux system installation, managing user accounts and filesystems, networking fundamentals, and Linux security techniques. Additionally, the book delves into the automation of applications and infrastructure using Chef, enabling you to streamline and optimize your operations. For both newcomers getting started with Linux and professionals looking to enhance their skills, this book is an invaluable hands-on guide with a structured approach and concise explanations that make it an effective resource for quickly acquiring and reinforcing Linux system administration skills. With the help of this Linux book, you’ll be able to navigate the world of Linux administration confidently to meet the demands of your role.
Table of Contents (21 chapters)
Part 1: Linux Basics
Part 2: Configuring and Modifying Linux Systems
Part 3: Linux as a Part of a Larger System

Understanding the/etc/sudoers file

In this section, let’s see how to use the ordinary user account we created earlier to carry out user administration operations.

We must make a special permissions entry for packt in /etc/sudoers in order to allow it special access:

packt ALL=(ALL) ALL

Let’s break down this line’s syntax:

  • First, we state to which user this rule applies (packt).
  • All hosts that use the same /etc/sudoers file are covered by the rule if the first ALL is present. Since the same file is no longer shared among different machines, this term now refers to the current host.
  • Next, (ALL) ALL informs us that any user may execute any command as the packt user. In terms of functionality, this is similar to (root) ALL.

It is important to manage permissions using groups as it makes life much easier. Imagine how simple it would be to just remove a user from a sudo group rather than removing the user from 100 different places.