Remote execution¶

Running pre-defined or arbitrary commands on remote hosts, also known as remote execution, is the core function of Salt. The following links explore modules and returners, which are two key elements of remote execution.

Modules

Salt modules, fundamental to remote execution, provide functionality such as installing packages, restarting a service, running a remote command, transferring files, and so on.

Full list of modules

Contains: a list of core modules that ship with Salt.

Writing modules

Contains: a guide on how to write Salt modules.

Returners

Salt returners allow saving minion responses in various datastores, or to various locations, in addition to displaying the responses at the CLI. Returners can be used to extend Salt to communicate with new, or custom, interfaces and to support new databases.

Full list of returners

Contains: list of returner modules used to store minion responses in Redis, Mongo, Cassandra, SQL, and others.

Writing returners

Contains: instructions for writing returner modules.

Targeting¶

Use targeting to specify which minions should execute commands and manage server configuration. The following links provide additional information about targeting and matching minions.

Globbing and regex

Match minions using globbing and regular expressions.

Grains

Match minions using grains, which are bits of static information about the minion such as OS, software version, virtualization, CPU, memory, and so on.

Pillar

Match minions using user-defined variables.

Subnet/IP Address

Match minions by subnet or IP address (currently IPv4 only).

Compound matching

Combine any of the above matchers into a single expression.

Node groups

Statically define groups of minions in the master config file using the compound matching syntax.

Batching execution

Loop through all matching minions so that only a subset are executing a command at one time.

Configuration management¶

Salt contains a robust and flexible configuration management framework, which is built on the remote execution core. This framework executes on the minions, allowing effortless, simultaneous configuration of tens of thousands of hosts, by rendering language specific state files. The following links provide resources to learn more about state and renderers.

States

Express the state of a host using small, easy to read, easy to understand configuration files. No programming required.

Full list of states

Contains: list of install packages, create users, transfer files, start services, and so on.

Pillar System

Contains: description of Salt's Pillar system.

States Overview

Contains: an overview of states and some of the core components.

Highstate data structure

Contains: a dry vocabulary and technical representation of the configuration format that states represent.

Writing states

Contains: a guide on how to write Salt state modules, easily extending Salt to directly manage more software.

Renderers

Renderers use state configuration files written in a variety of languages, templating engines, or files. Salt's configuration management system is, under the hood, language agnostic.

Full list of renderers

Contains: a list of renderers. YAML is one choice, but many systems are available, from alternative templating engines to the PyDSL language for rendering sls formulas.

Renderers

Contains: more information about renderers. Salt states are only concerned with the ultimate highstate data structure, not how the data structure was created.

Miscellaneous topics¶

The following links explore various Salt topics in depth.

Salt Cloud

Salt Cloud is a public cloud provisioning tool that integrates Salt with many cloud providers.

File Server

Salt can easily and quickly transfer files (in fact, that's how Salt states work). Even under heavy load, files are chunked and served.

Syndic

Syndic is a tool to allow one master host to manage many masters, which in turn manage many minions. Scale Salt to tens of thousands of hosts or across many different networks.

Peer Communication

Allow minions to communicate among themselves. For example, configure one minion by querying live data from all the others.

Reactor System

The reactor system allows for Salt to create a self aware environment by hooking infrastructure events into actions.

Firewall Settings and Salt

This is a tutorial covering how to properly firewall a Salt Master server.

Scheduling Executions (like states)

The schedule system in Salt allows for executions to be run from the master or minion at automatic intervals.

Network topology

At it's core, Salt is a highly scalable communication layer built on top of ZeroMQ, which enables remote execution and configuration management. The possibilities are endless and Salt's future looks bright.

Testing Salt

This is a tutorial for writing unit tests and integration tests.

Salt Proxy Minions

Proxy minions allow for the control of devices and machines which are unable to run a salt-minion.

Python API interface

The Python API allows the developer to use Salt locally from scripts and programs easily via import salt.

External API interfaces

Expose a Salt API such as REST, XMPP, WebSockets, or others using netapi modules. Run these modules using the salt-api daemon. See the full list of netapi modules.

Automatic Updates and Frozen Binary Deployments

Use a frozen install to make deployments easier (even on Windows!). Or take advantage of automatic updates to keep minions running the latest builds.

Windows Software Manager / Package Repository

Looking for an easy way to manage software on Windows machines? Search no more! Salt has an integrated software package manager for Windows machines! Install software hosted on the master, anywhere on the network, including any HTTP, HTTPS, or ftp server.

Reference¶

Command-line interface

Read the Salt manpages.

Full list of master settings

Read through the heavily-commented master configuration file.

Full list of minion settings

Read through the heavily-commented minion configuration file.

Full table of contents

Read the table of contents of this document.