Ansible is a powerful automation tool that simplifies IT infrastructure management. Unlike other tools, Ansible is agentless, meaning it doesn't require any software to be installed on the servers you want to manage. It connects to remote systems using SSH and executes tasks defined in simple YAML files called playbooks.
Ansible has four main components. The Control Node is where Ansible is installed and from where you run your automation. Managed Nodes are the target systems you want to configure. The Inventory is a file that lists all your managed nodes and can organize them into groups. Playbooks are YAML files that contain the tasks you want to execute on your managed nodes.
Here's how Ansible works step by step. First, you write a playbook that defines what tasks you want to perform. Then you run the ansible-playbook command, which reads your inventory and connects to the managed nodes via SSH. Ansible transfers the necessary modules to each target system, executes the tasks, and collects the results back to the control node.
Here's a simple Ansible playbook example. The playbook is written in YAML format and defines tasks to install and start Apache web server on multiple servers. The playbook specifies the target hosts as 'webservers', uses privilege escalation with 'become yes', and contains two tasks: installing the Apache package and starting the service. When you run this playbook, Ansible executes these tasks on all specified servers simultaneously.
In summary, Ansible is a powerful automation tool that simplifies IT infrastructure management through its agentless architecture, human-readable YAML syntax, and idempotent operations. It connects to managed nodes via SSH, executes tasks defined in playbooks, and provides immediate feedback. With over 3000 built-in modules and support for custom modules, Ansible is both powerful and flexible, making it an excellent choice for configuration management, application deployment, and infrastructure automation.