An SPM file is a package created by Salt Package Manager (SPM), a program used to package Salt formulas to distribute them to Salt masters. It is a compressed folder that contains a collection of pillar, jinja, and state files that make up a formula. SPM files can be used for various purposes, such as setting up users or permissions or configuring and starting a service.

To build an SPM package organize the formula files in a folder on the build system, create a FORMULA file (stores metadata used by SPM) in the root of the package folder, and run spm build <folder name>. The package is built in the /srv/spm_build folder. Salt is a configuration management system that is used to maintain remote nodes in defined states. It can also be used as a distributed remote execution system to execute commands and search data on remote nodes. A Salt master is a server that acts as a central control bus for the minions, which are clients. For more information about Salt, click here.