Building reactors

Now you have seen what events look like, but what can you do with them? One of the most powerful features that distinguishes Salt from similar systems is not only its ability to fire events, but also the ability for the master to initiate new jobs based on the information contained in the event.

This reactor system serves as a platform for users to build systems that are both asynchronous and autonomous, which can range from simple to very complex.

Configuring reactors

Reactors are master-side processes, so none of the configuration needs to happen directly on any minions. In fact, as the reactor system needs to actively listen to an event bus in order for it to function, it doesn't even make sense to attempt to use it in a masterless environment based on the salt-call commands.

Before setting up the master, decide which directory will contain reactor files. By convention, this will be /srv/reactor/, but this is not a hardcore requirement and is not enforced anywhere in Salt...