Built on Python, Salt is an event-driven automation tool and framework to deploy, configure, and manage complex IT systems. Salt is used to automate common infrastructure administration tasks and ensure that all the components of infrastructure are operating in a consistent desired state.
Managing heterogeneous environments of large numbers of nodes, especially nodes which may need sudden changes (security updates, for instance), or frequent replacement, is a strength for Saltstack. Simplicity is not a strength for Saltstack. In a homogenous environment (all CentOS 7, for example, with no Debian or Windows) I might recommend using Ansible instead - it is less flexible and granular, but simpler to configure.
A superb remote execution framework! SaltStack allows us to easily program numerous functions on top of it. For example, we developed a fast parallel asynchronous deployment tool that handles all software deployment, including interdependent service management.
Configuration management is now easy. We take advantage of this to automate (in tandem with AWS tools) the stand-up of all servers and services. It is also relatively easy to create new configuration management states for software not yet supported by the community (e.g. Grafana).
Flexibility. Numerous small utilities have been built which simply wrap around SaltStack to allow tedious tasks to become easy.
We haven't had to spend a lot of time talking to support, and we've only had one issue, which, when dealing with other vendors is actually not that bad of an experience.
I've used shell scripts over ssh, custom in-house deployment tools, Chef, and SaltStack. I've evaluated Ansible, but I was never happy with performance over SSH. Chef's loose configuration data model and lack of philosophy and conventions around use makes it difficult for a team to share responsibility for configuration code. Needing to use additional tools to do orchestration for cross-host/agent dependency relationships made me look for more. SaltStack, while not as mature when I first tried it, impressed me with its speed and elegant design
