What is an open-source, Python-based software for event-driven IT automation?

The correct answer is Ansible. Ansible is an open-source IT automation tool written in Python that focuses on event-driven automation. It enables users to manage configurations, deployment, and orchestration tasks efficiently with a simple, human-readable language. Ansible operates by pushing out code to remote systems, allowing for easier management of large infrastructures without requiring agents or daemons on managed nodes.

In addition to its capabilities for configuration management, Ansible is known for its lightweight nature and ease of use, making it accessible for automation tasks across various IT environments. This ability to automate entire workflows and processes through playbooks written in YAML (Yet Another Markup Language) sets it apart from other options.

Puppet, Saltstack, and Chef are also popular automation tools, but they have different architectures and programming models. Puppet and Chef, for example, often require an agent installed on managed nodes, while Saltstack, although also event-driven, is structured differently and utilizes a master-minion architecture. This makes Ansible's approach uniquely suited for those looking for a straightforward, agent-less automation solution.