Study the material in this book to prepare for the RHCE exam EX294 and to learn how using Ansible within your own environment improves system administration productivity.

This book covers all of the objectives of the exam and extends further, ensuring that you know how to use Ansible to manage Linux. The book uses CentOS, a Red Hat-based distribution, and Ubuntu instead of using a single Red Hat distribution. By using the two distributions, you will understand the power of Ansible and how easily you can deal with multiple platforms, which is crucial for your understanding of Ansible in the real world.

The book assumes no previous knowledge of Ansible but some knowledge of Linux system administration from the command line. You will learn how to manage Linux systems that are installed with different distributions, including CentOS Enterprise Linux 8 and Ubuntu 18.04. You will be able to manage these systems using ad hoc commands from the command line as well as creating Ansible playbooks that can be replayed reliably many times. To save on the code that you have to create, you will learn how to use Ansible Galaxy to search for and download roles and collections that are pre-written to manage elements of your Linux installations. By the end of this book, you will be able to write efficient and effective YAML playbooks to manage your entire estate.

What You Will Learn
• Prepare systems so that password-less access can be used with Ansible remotely
• Use ad hoc commands to quickly configure systems
• Use and format YAML files correctly
• Create playbooks that grow in their complexity as your experience develops
• Ensure that services are restarted on configuration changes

Who This Book Is For

Those who want to prepare for the RHCE exam EX294 and readers who want to learn how to use Ansible to improve the productivity of their system administration. This book will help you prepare yourself for the exam as well as your real-life administration needs.

学习本书中的材料，准备参加RHCE考试EX294，并学习如何在自己的环境中使用Ansible来提高系统管理效率。

本书涵盖了考试的所有目标，并进一步延伸，确保你知道如何使用Ansible来管理Linux。本书使用了CentOS，一个基于Red Hat的发行版，以及Ubuntu，而不是使用单一的Red Hat发行版。通过使用这两个发行版，你将了解Ansible的强大功能，以及如何轻松处理多个平台，这对你在现实世界中理解Ansible至关重要。

本书假设之前没有Ansible的知识，但有一些从命令行管理Linux系统的知识。你将学习如何管理安装有不同发行版的Linux系统，包括CentOS Enterprise Linux 8和Ubuntu 18.04。你将能够使用命令行中的临时命令来管理这些系统，以及创建可以多次可靠重放的Ansible播放程序。为了节省你必须创建的代码，你将学习如何使用Ansible Galaxy来搜索和下载角色和集合，这些角色和集合是预先写好的，用于管理你的Linux安装元素。在本书结束时，你将能够编写高效的YAML操作手册来管理你的整个资产。

你将学到的内容

- 准备好系统，以便可以使用Ansible远程的无密码访问。

- 使用专门的命令来快速配置系统

- 正确使用和格式化YAML文件

- 随着经验的积累，创建复杂度更高的操作手册

- 确保服务在配置变更时被重新启动

本书适用对象

想准备RHCE考试EX294的人，以及想学习如何使用Ansible来提高系统管理效率的读者。本书将帮助你为考试以及现实生活中的管理需求做准备。