SaltStack

SaltStack, also known as Salt, is an open source infrastructure management platform that handles configuration management, remote execution, monitoring, and orchestration at scale. It uses a master-minion architecture where a central Salt master communicates with targeted minion agents over a secure ZeroMQ or TCP transport. Instead of a strict DSL, Salt lets you define states in YAML with Jinja templating, making it approachable for sysadmins who already write configuration files. The event-driven reactor system can trigger automated responses to infrastructure changes, and the flexible targeting system supports glob, regex, grain, and compound matchers. Salt ships with hundreds of built-in execution modules and state modules for managing packages, services, users, files, cloud resources, and more. The project started at SaltStack Inc. (later acquired by VMware) and lives on as an open source community project under the Salt Project umbrella with contributors from VMware and others. Salt is a natural fit for billing automation pipelines: you can write custom execution modules to query usage data from databases, then apply state files that push firewall rules or adjust service tiers. The external pillar system lets you pull inventory and metering data from external APIs before running states. Because Salt runs on Linux and can manage Windows minions, it works well for heterogeneous hosting environments.