Overview

An indepth look at Automating Red Hat Linux 8 Using Ansible, for the experienced Linux Administrator who wants to broaden their skills towards the Red Hat RHCE certification. Delegates should already have good system administration skills and be able to work comfortably at the Linux CLI.

Audience

This course is the final step in our 3 course path for administrators new to Red Hat 8 or CentOS 8, it is also ideal for those who wish to go on to become certified with the RHCSA exam.

Prerequisites

Attendance on Red Hat Enterprise Linux 8 - Linux Admin 1 and Red Hat Enterprise Linux 8 - Linux Admin 2 courses or equivalent previous experience with the Red Hat Linux system is required.

Objectives

An indepth look at Automating Red Hat Linux 8 Using Ansible, for the experienced Linux Administrator who wants to broaden their skills towards the Red Hat RHCE certification. Delegates should already have good system administration skills and be able to work comfortably at the Linux CLI.

Topics

What is Ansible?
An introduction to Ansible Configuration Management in CentOS 8 and where it is used.

Configuring and Using Ansible
In this module we look at creating inventory files, host lists, and managing the Ansible configuration, ansible.cfg including the use of read-only variables to secure the configuration location. With the basics in-place we can show using ad-hoc commands the power of Ansible.

Writing Ansible Playbooks
Playbooks are central to Ansible and both document the configuration as well as implementing it; in this module you will learn to format, create and execute Playbooks. Involving ourselves in this objective we will see how we can create and distribute SSH Key to allow for password-less access to managed hosts.

Gathering Ansible Facts and Using Variables
Variables allow a Playbook to be more flexible as we can cater for differences needed. Some of those variables we will create others will come from facts on a system, such as the IP Address of a Host.

Controlling Ansible Tasks
Using conditional and loops structures in tasks help provide for a more robust and efficient Playbook. Using both CentOS and Ubuntu based distributions we can easily show how this helps in targeting the correct task.

Deploying Files and Templates
Looking at the copy, lineinfile and the template modules we are able to look at different ways to send data to managed node filesystems.

Managing Enterprise Projects
As we start to work with more hosts we can look at adjusting the parallelism of Ansible and the number of concurrent connections that can be made.

Using Roles
Roles can help your Playbooks maintain their simplicity whist carrying out complex tasks. If we needed to deploy Apache and MariaDB we could create a role for each service and deploy both roles from the main Playbook.

Troubleshooting Ansible
We will look at ways to troubleshoot the Playbook and managed hosts so you can keep your systems running.

Practical Ansible
Working through many examples we will see both the how and the why of Ansible Configuration Management including configuring scheduled tasks and configuring AWS instances.

Limit network communication with FirewallD
Configure a basic firewall and understand SELinux Ports.

Firewalls with nftables
For more exacting control of your firewall you will want to use the native firewall which is nftables in RHEL 8. Using nft you will learn to create rules to support multiple protocol stacks.