Chapter 3. Understanding Ansible concepts

Playbooks are files written in YAML that contain specific sets of human-readable instructions, or “plays”, that you send to run on a single target or groups of targets.

Playbooks can be used to manage configurations of and deployments to remote machines, as well as sequence multi-tier rollouts involving rolling updates. Use playbooks to delegate actions to other hosts, interacting with monitoring servers and load balancers along the way. Once written, playbooks can be used repeatedly across your enterprise for automation.

A role is Ansible’s way of bundling automation content as well as loading related vars, files, tasks, handlers, and other artifacts automatically by utilizing a known file structure. Instead of creating huge playbooks with hundreds of tasks, you can use roles to break the tasks apart into smaller, more discrete and composable units of work.

You can find roles for provisioning infrastructure, deploying applications, and all of the tasks you do every day on Ansible Galaxy. Filter your search by Type and select Role. Once you find a role that you’re interested in, you can download it by using the ansible-galaxy command that comes bundled with Ansible:

$ ansible-galaxy role install username.rolename

An Ansible Content Collection is a ready-to-use toolkit for automation. It includes multiple types of content such as playbooks, roles, modules, and plugins all in one place. The diagram below shows the basic structure of a collection:

collection/
├── docs/
├── galaxy.yml
├── meta/
│   └── runtime.yml
├── plugins/
│   ├── modules/
│   │   └── module1.py
│   ├── inventory/
│   ├── lookup/
│   ├── filter/
│   └── .../
├── README.md
├── roles/
│   ├── role1/
│   ├── role2/
│   └── .../
├── playbooks/
│   ├── files/
│   ├── vars/
│   ├── templates/
│   ├── playbook1.yml
│   └── tasks/
└── tests/
    ├── integration/
    └── unit/

In Red Hat Ansible Automation Platform, automation hub serves as the source for Ansible Certified Content Collections.

Automation execution environments are consistent and shareable container images that serve as Ansible control nodes. Automation execution environments reduce the challenge of sharing Ansible content that has external dependencies.

Automation execution environments contain:

You can define and create an automation execution environment using Ansible Builder.