Ansible Automation: Your First Playbook

Ansible lets you automate server configuration, deployments, and repetitive IT tasks without installing agents on target machines. It uses SSH and YAML — nothing complicated.

Prerequisites

• A Linux control node (your workstation or a jump box)
• One or more target servers with SSH access
• Python 3 installed on all machines

Step 1: Install Ansible

# Ubuntu/Debian
sudo apt update
sudo apt install ansible
Or via pip
pip3 install ansible
Verify
ansible --version

Step 2: Create Your Inventory

Create inventory.ini:

[webservers]
web1 ansible_host=192.168.1.10
web2 ansible_host=192.168.1.11
[dbservers]
db1 ansible_host=192.168.1.20
[all:vars]
ansible_user=admin
ansible_ssh_private_key_file=~/.ssh/id_rsa

Test connectivity:

ansible all -i inventory.ini -m ping

Step 3: Write Your First Playbook

Create setup-webserver.yml:

---
name: Set up web servers
  
hosts: webservers
  become: yes
  tasks:
    - name: Update apt cache
      apt:
        update_cache: yes
        cache_valid_time: 3600
    - name: Install Nginx
      apt:
        name: nginx
        state: present
    - name: Start and enable Nginx
      systemd:
        name: nginx
        state: started
        enabled: yes
    - name: Copy custom index page
      copy:
        content: |
          <h1>Hello from {{ inventory_hostname }}</h1>
          <p>Deployed by Ansible</p>
        dest: /var/www/html/index.html
    - name: Open firewall port 80
      ufw:
        rule: allow
        port: "80"
        proto: tcp

Run it:

ansible-playbook -i inventory.ini setup-webserver.yml

Step 4: Use Variables and Templates

Create group_vars/webservers.yml:

http_port: 80
server_admin: [email protected]

Create a Jinja2 template templates/nginx.conf.j2:

server {
    listen {{ http_port }};
    server_name {{ inventory_hostname }};
    root /var/www/html;
    location / {
        try_files $uri $uri/ =404;
    }
}

Use the template in your playbook:

- name: Deploy Nginx config
      template:
        src: templates/nginx.conf.j2
        dest: /etc/nginx/sites-available/default
      notify: Restart Nginx
  handlers:
    - name: Restart Nginx
      systemd:
        name: nginx
        state: restarted

Step 5: Use Roles for Organization

ansible-galaxy init roles/webserver

This creates a structured directory:

roles/webserver/
  tasks/main.yml
  handlers/main.yml
  templates/
  files/
  vars/main.yml
  defaults/main.yml

Essential Ansible Commands

• ansible all -m ping — Test connectivity
• ansible-playbook playbook.yml --check — Dry run
• ansible-playbook playbook.yml --diff — Show changes
• ansible-playbook playbook.yml --limit web1 — Run on specific host
• ansible-vault encrypt secrets.yml — Encrypt sensitive files

Conclusion

You've written your first Ansible playbook and learned the core concepts. Ansible scales from managing 2 servers to 2000 with the same simple YAML syntax. Start automating your repetitive tasks today.