Book Image

CentOS 7 Linux Server Cookbook - Second Edition

By : Jonathan Hobson
Book Image

CentOS 7 Linux Server Cookbook - Second Edition

By: Jonathan Hobson

Overview of this book

This book will provide you with a comprehensive series of starting points that will give you direct access to the inner workings of the latest CentOS version 7 and help you trim the learning curve to master your server. You will begin with the installation and basic configuration of CentOS 7, followed by learning how to manage your system, services and software packages. You will then gain an understanding of how to administer the file system, secure access to your server and configure various resource sharing services such as file, printer and DHCP servers across your network. Further on, we cover advanced topics such as FTP services, building your own DNS server, running database servers, and providing mail and web services. Finally, you will get a deep understanding of SELinux and you will learn how to work with Docker operating-system virtualization and how to monitor your IT infrastructure with Nagios. By the end of this book, you will have a fair understanding of all the aspects of configuring, implementing and administering CentOS 7 Linux server and how to put it in control.
Table of Contents (22 chapters)
CentOS 7 Linux Server Cookbook Second Edition
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Working with policies


At the core of every SELinux system are the policies. These are the exact rules that define the access rights and relationships between all our objects. As we have learned earlier, all our system's objects have labels, and one of them is a type identifier that can then be used to enforce rules laid down by policies. In every SELinux enabled system, by default, all access to any object is prohibited unless a policy rule has been defined otherwise. Here, in this recipe, we will show you how we can query and customize SELinux policies. As you may notice, some of the commands have already been applied in other recipes in this book, such as for the httpd or ftpd daemons. Here, you will find out how policies work.

Getting ready

To complete this recipe, you will require a working installation of the CentOS 7 operating system with root privileges. It is assumed that you are working through this chapter recipe by recipe, so by now you should have installed the SELinux tools from...