SaltStack

SaltStack, commonly referred to as Salt, is an open-source software system for configuration management, remote execution, and automation. It is designed to manage large-scale infrastructure and is written in Python. Salt supports Linux, Windows, and macOS and can operate in a master-minion model or in an agentless mode via Salt SSH for managing hosts without an installed agent.

The core architecture revolves around a central Salt Master that communicates with Salt Minions installed on managed hosts. The system uses a message bus over TCP (originally ZeroMQ) to issue commands and collect results. Key concepts include execution modules (for performing tasks), states or SLS files (for declaring the desired configuration), grains (system facts), pillar data (secure, structured information), and the reactor for event-driven automation. Salt also provides orchestration tools and runners to coordinate complex workflows.

Major features include remote execution, declarative configuration management, and orchestration. Salt supports event-driven automation, real-time monitoring, and cloud provisioning through Salt Cloud, enabling management across on-premises and multi-cloud environments. Its architecture allows scalable management of thousands of nodes and supports multi-platform deployments.

Salt is released under an open-source license (Apache 2.0) and has a broad ecosystem of community modules. It also offers enterprise-grade editions with additional management features, dashboards, security controls, and official support. The project is widely used in DevOps and IT operations to automate configuration, deployment, and ongoing management of large, heterogeneous infrastructures.

SaltStack was created by Thomas S. Hatch and first released in 2011. In 2020, SaltStack was acquired by VMware, with Salt continuing as an open-source project alongside enterprise offerings and related tooling.