How is automation of configuration and infrastructure management implemented with Ansible?

Ansible is a tool for automation of configuration and infrastructure management that uses a declarative approach and SSH for interacting with remote servers.

Automation with Ansible is implemented through:

• Playbooks — YAML files describing the desired state of the system (installing packages, configuring services, copying files, etc.).
• Modules — built-in or custom scripts that perform specific tasks (for example, the apt module for installing packages on Debian/Ubuntu).
• Inventory — a list of managed hosts grouped by roles or environments.

An example of a simple playbook for installing and starting nginx:

- hosts: webservers
  become: yes
  tasks:
    - name: Install nginx
      apt:
        name: nginx
        state: present
        update_cache: yes

    - name: Start and enable nginx
      service:
        name: nginx
        state: started
        enabled: yes

The playbook is run with the command:

ansible-playbook -i inventory.ini playbook.yml

Thus, Ansible allows describing infrastructure as code, which facilitates repeatability, scalability, and change control.