The queue system is another component of Salt with the ability to fire events. This can be used by the Reactor system. However, before we get ahead of ourselves, let's go through the basics of using the queue system.
At its most basic level, the queue is very simple. Items can be added to the queue and then processed at a later time in the order in which they were added. Depending on the queue module being used, items may or may not be required to be unique.
For our examples, we'll use
sqlite: the default queue module. This module should work in any infrastructure because
sqlite3 is built in Python. It will also automatically generate any database files if they don't already exist. Take note that
sqlite is one of the queue modules that requires items to be unique. If you want to use a different module, just add a backend argument to any of the queue commands. For instance, to explicitly list queues stored in
sqlite, use the following command: