How does Tanzu Salt work

Tanzu Salt includes four or more architectural components including the RaaS server, the Master Plugin, and two central databases.

The following diagram shows the primary components of the basic Tanzu Salt architecture that are relevant to installation:

Note:
As part of VMware’s initiative to remove problematic terminology, the term Salt master will be replaced with a better term in Tanzu Salt and related products and documentation. This terminology update may take a few release cycles before it is fully complete.

Salt Masters and the Master Plugin

Tanzu Salt is powered by Salt, an open-source configuration management and automation system.

The Salt master is the main connection between Tanzu Salt and the rest of the nodes on your network (the minions). When you issue a command from Tanzu Salt (such as a job), the command goes to the Salt master for distribution to the targeted minions.

Tanzu Salt can connect to one Salt master or many masters as needed in your system. In order for Tanzu Salt to communicate with a Salt master, you must install the Master Plugin on the Salt master and accept its key in Tanzu Salt. The Master Plugin allows the Salt master to access jobs or processes initiated by Tanzu Salt. The Salt Master can access external files and pillar data that are stored on the PostgreSQL database.

The plugin integrates with the existing extension points provided by Salt. For example, job returns are collected using a Salt master-side Salt external job cache, and the RaaS file server uses a Salt fileserver plugin.

Note:
You can connect more than one Salt master to Tanzu Salt. Each Salt master that connects to Tanzu Salt must have the Master Plugin installed.

RaaS

RaaS, which stands for Returner as a Service, is the central component in Tanzu Salt. In fact, when some people refer to Tanzu Salt itself, they are often talking about RaaS.

RaaS provides RPC endpoints to receive management commands from the Tanzu Salt user interface, as well as RPC control endpoints to interface with connected Salt masters. All communication is sent using RPC API calls over WebSockets or HTTP(s).

Tanzu Salt user interface

The Tanzu Salt user interface is a web application that provides the graphical user interface front end for RaaS. Though Tanzu Salt is API-first, the user interface interfaces directly with the API (RaaS) to enable simple management of all systems in your environment. Different workspaces provide users with the ability to manage minions, users, roles, jobs, and more.

Databases

PostgreSQL Database

RaaS uses a PostgreSQL database to store minion data, job returns, event data, files and pillar data, local user accounts, and other settings for the user interface.

Redis Database

RaaS uses a Redis database to store certain types of data in temporary storage, such as cached data. It also uses temporary data storage to distribute queued work to background workers.

For more information on how Salt works, see Salt System Architecture.