Ansible Roles: Day 4 of Ansible Zero to Hero Series

Introduction

• Episode 4 of Ansible Zero to Hero series
• Recap of Episodes 1-3
  • Episode 1: Introduction to Ansible and getting started
  • Episode 2: Ansible ad-hoc commands
    • Passwordless authentication
    • Using the inventory file
    • Example ad-hoc commands
  • Episode 3: Writing the first Ansible Playbook
    • Basics of YAML
    • Ansible Playbook structure
    • Ansible plays, modules, and tasks
    • Installed Apache and deployed a web application using the Playbook

Focus of Day 4: Ansible Roles

• Objective: Learn basics of Ansible roles:
  • Understand what Ansible roles are
  • Why use Ansible roles
  • Folder structure of Ansible roles
  • Compare roles with Playbooks
  • Create a sample role
• Future Plans:
  • Day 5: Deep dive into Ansible roles
    • Shared roles across organizations
    • Writing complicated roles

Recap of Day 3: Ansible Playbook Structure

• Ansible Playbook is a YAML file
• Collection of plays within a Playbook
  • Each play has fields like host, variables, remote user, tasks
• Tasks: Collection of actions for target servers
  • Provide a module in each task
• Workflow:
  1. DevOps engineer writes Playbook
  2. Playbook fed as input to control node
  3. Control node processes the tasks and executes them on managed nodes

Today's Topic: Ansible Roles

• Introduction to Ansible Roles:
  • Simplifies managing complex Playbooks
  • Improve readability and modularity
  • Roles break down Playbooks into several directories and files
  • Easier to manage Playbooks with many tasks and variables
• Why use Ansible Roles?:
  • Improves readability
  • Enhances modularity
  • Easier to understand and troubleshoot
  • Can be shared across teams and organizations
  • Use cases: Complicated tasks like Kubernetes installation, database configuration
• Creating Ansible Roles:
  • Command: ansible-galaxy role init <role_name>
  • Role created with necessary folder structure
  • Splits tasks and other sections into respective directories
• Folder Structure of Ansible Roles:
  • vars: Contains variables
  • tasks: Contains tasks
  • meta: Metadata about the role
  • handlers: Tasks executed upon specific events
  • files: Static files needed for tasks
  • templates: Dynamic files using Jinja2 for variable replacement
  • defaults: Default values for variables

Practical Example: Converting Playbook to Role

• Steps: Convert Day 3 Playbook into a Role
  • Use ansible-galaxy role init httpd to create role
  • Move tasks, files, and other parts into the respective folders
  • Adjust file paths in tasks to point to new directory structure
• Advantages of Roles:
  • Reduces complexity
  • Modularizes tasks
  • Improves code sharing and reuse

Execution of Role

• Run ansible-playbook -i inventory.ini first_playbook.yaml
• Results after conversion:
  • GATHERING FACTS, install Apache, copy files, no changes detected (idempotency)
  • Tasks run successfully upon manual file removal, verifying role works as expected

Summary

• Ansible roles improve readability, modularity, and code sharing
• Next episode will cover more advanced topics related to roles and Ansible Galaxy

Conclusion

• Thank you for watching, hope you found it useful
• Stay tuned for the next episode