The Ultimate Red Hat Ansible Cheat Sheet

In the dynamic landscape of IT operations, automation has become a crucial component for efficiency and scalability. Red Hat Ansible, an open-source automation tool, stands out as a powerhouse for managing and orchestrating complex systems. To empower both beginners and seasoned users, we present "The Ultimate Red Hat Ansible Cheat Sheet." This comprehensive guide will serve as your go-to resource for mastering Ansible and streamlining your automation tasks.

1. Getting Started with Ansible:
   Before diving into the cheat sheet, ensure that Ansible is installed on your system. For newcomers, the command to install Ansible on a Red Hat-based system is:

   sudo yum install ansible
   

2. Ansible Inventory:
   The inventory file is the backbone of Ansible, defining the hosts and groups. Create a simple inventory file:

   [web_servers]
   server1 ansible_host=192.168.1.10
   server2 ansible_host=192.168.1.11
   

3. Basic Ansible Commands:

   • Execute a command on all hosts:

     ansible all -a "command"
     

   • Run a playbook:

     ansible-playbook playbook.yml
     

4. Ad-Hoc Commands:
   Ansible's ad-hoc commands are powerful for quick tasks. For instance, to update all packages on a group of servers:

   ansible web_servers -a "yum update -y"
   

5. Playbooks:
   Playbooks are Ansible's configuration, deployment, and orchestration language. Create a playbook file (example.yml) for installing a package:

   ---
   - name: Install Apache
     hosts: web_servers
     tasks:
       - name: Install Apache
         yum:
           name: httpd
           state: present
   

6. Variables and Facts:
   Utilize variables for dynamic playbooks. Define variables in a playbook:

   ---
   - name: Use Variables
     hosts: web_servers
     vars:
       http_port: 80
     tasks:
       - name: Ensure Apache is running
         service:
           name: httpd
           state: started
   

7. Handlers:
   Handlers are tasks that run only when notified. For example, to restart Apache if the configuration file changes:

   ---
   - name: Configure Apache
     hosts: web_servers
     tasks:
       - name: Copy Apache config
         copy:
           src: files/httpd.conf
           dest: /etc/httpd/conf/httpd.conf
         notify: Restart Apache
     handlers:
       - name: Restart Apache
         service:
           name: httpd
           state: restarted
   

8. Roles:
   Organize your playbooks with roles. Create a role structure using:

   ansible-galaxy init role_name
   

9. Vaults:
   Secure sensitive data using Ansible Vault. Create an encrypted file:

   ansible-vault create secret.yml
   

10. Dynamic Inventories:
    Dynamically discover hosts with custom scripts or plugins. Ensure the dynamic inventory script is executable:

    chmod +x dynamic_inventory.py
    

11. Troubleshooting:
    Debug Ansible runs with verbose mode:

    ansible-playbook -v playbook.yml
    

Congratulations! You've just scratched the surface of mastering Red Hat Ansible with "The Ultimate Red Hat Ansible Cheat Sheet." This quick reference will undoubtedly prove invaluable as you automate and streamline your IT infrastructure. Keep exploring the vast capabilities of Ansible, and may your automation journey be smooth and efficient.