Getting Started With Ansible: Key Concepts

Introduction:

Ansible is a powerful automation tool that can simplify your IT configuration tasks and boost productivity.  If you've found yourself overwhelmed with repetitive manual tasks, Ansible might be your new best friend.  Let's look at some of Ansible's key concepts.  I'll dive into the details in upcoming posts, so be sure to check back frequently or subscribe to get notified. 

What is Ansible?

Ansible is an open-source tool that enables you to automate various IT tasks, from software provisioning and configuration management to application deployment and task orchestration. What sets Ansible apart is its simplicity and agentless architecture, making it an ideal choice for IT professionals looking to streamline their workflow.

Key Concepts:

1. Control node: The control node is where the Ansible CLI tools are installed: ansible-playbook, ansible, ansible-vault, ansible-rulebook, etc.  Any computer that meets the software requirements can be used as a control node.  Almost any UNIX-like machine with Python 3.9 or newer can be used.  With the introduction of the Windows Subsystem for Linux, Windows can also be used.  We'll cover the installation process on WSL in a future blog post.
2. Playbooks:  Playbooks are written in YAML format and describe a series of tasks to be executed on remote or local hosts.  These tasks can include installing software, configuring services, installing patches, and more.  The YAML format is easy to read and understand, but can be a bit of a nuisance trying to remember the correct spacing.  Fortunately, ansible-lint can help provide guidance on formatting and checks for practices and behaviors that could be improved.
3. Inventory:  Ansible keeps track of your infrastructure through an inventory file listing all the hosts you want to manage.  This file can be a simple text file or dynamically generated from various sources.  You can organize your hosts into groups and apply playbooks to specific groups or individual hosts (database servers vs. web servers for example).  These can be written as a basic INI file or in YAML format. 
4. Modules:  Ansible provides many built-in modules for performing tasks on remote hosts.  Modules are like building blocks that allow you to interact with the target system.  For example, the `apt` module manages packages on Debian-based systems, while the `yum` module is used for Red Hat-based systems. Win_chocolatey can be used to manage software packages on Windows systems.
5. Tasks and Handlers:  Tasks define the actions you want to perform on remote hosts, such as copying files, installing software, or restarting services.  Handlers are special tasks triggered only when other tasks notify them, which is useful for ensuring changes are applied only when needed.
6. Roles:  Roles are a way to organize your playbooks and make them more reusable.  They encapsulate tasks, variables, and files into a structured directory hierarchy, allowing you to share and manage automation code easily.
7. Templates:  You create template files in your Ansible roles using the `.j2` extension to indicate they are Jinja2 templates.  These files contain a combination of static content and placeholders for dynamic values.  We'll dive into templates in a later post.
8. Rulebooks:  Rulebooks are new and part of Event-driven automation for Ansible.  ansible-rulebook is a command line tool that allows you to recognize events that you care about and react accordingly by running a playbook or other actions.  Think of this as a way to fire an action based on an alert from a monitoring system.

Conclusion:

With Ansible, you have the power to automate repetitive IT configuration tasks, save time, and reduce the risk of human error. As you embark on your automation journey, keep in mind that practice makes perfect. Experiment with playbooks, explore Ansible's vast module library and gradually automate more complex tasks.  A great place to experiment is in your own virtual lab environment.  In our next post, we'll set up the control node on Windows and a Red Hat Enterprise Linux machine.

To help you get started, don't forget to download our time tracker workbook. This valuable tool will assist you in identifying common repetitive tasks in your IT workflow, paving the way for efficient automation with Ansible. Happy automating!