Get started with Salt¶
Salt is an open source tool to manage your infrastructure. Easy enough to get running in minutes and fast enough to manage tens of thousands of servers (and still get a response back in seconds).
Execute arbitrary shell commands or choose from dozens of pre-built modules of common (or complex) commands. Target individual servers or groups of servers based on name, defined roles, or a variety of system information such as hardware, software, operating system, current version, current environment, and many more.
Bring your servers up to a known configured state by writing simple lists of items and defining attributes on those lists—no need to learn yet another language.
Read the Salt overview for a more thorough description.
Tutorial 1: Remote execution¶
Screencasts
Watch the remote execution screencast.
The quickest way to see Salt in action is to run a command on a minion host from the master host. This is widely known as remote execution — executing commands on remote hosts.
Tutorial 2: Configuration management¶
Now that you have the basics out of the way, learn to use Salt to configure your servers. This is widely known as configuration management — installing packages, configuring users and services, and much more.
Salt in depth¶
Setting up and using Salt is a simple task but its capabilities run much, much deeper. Gaining a better understanding of how Salt works will allow you to truly make it work for you.
The components of Salt
Targeting¶
Targeting is specifying which minions should execute commands or manage server configuration.
- Globbing and regex
- Match minions using globing and regular expressions.
- Grains
- Match minions using bits of static information about the minion such as OS, software versions, virtualization, CPU, memory, and much more.
- Node groups
- Statically define groups of minions.
- Compound matchers
- Combine the above matchers as a single target.
- Batching execution
- Loop through all matching minions so that only a subset are executing a command at one time.
Remote execution¶
Remote execution is the core functionality of Salt. Running pre-defined or arbitrary commands on remote hosts.
- Modules
Salt modules are the core of remote execution. They provide functionality such as installing a package, restarting a service, running a remote command, transferring a file — and the list goes on.
- Full list of modules
- The giant list of core modules that ship with Salt (And there are even more in the salt-contrib repository!)
- Writing modules
- 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 display at the CLI.
- Full list of returners
- Store minion responses in Redis, Mongo, Cassandra or more.
- Writing returners
- If we're missing your favorite storage backend, webservice, or you need a custom endpoint returners are tiny and simple to write.
Configuration management¶
Building on the remote execution core is a robust and flexible config management framework. Execution happens on the minions allowing effortless, simultaneous configuration of thousands of hosts.
- States
Express the state of a host using small, easy to read, easy to understand configuration files. No programming required (unless you want to).
- Full list of states
- Install packages, create users, transfer files, start services, and much more.
- Using states
- You've seen the big list of available states, now learn how to call them.
- Highstate data structure
- A dry vocabulary and technical representation of the configuration format that states represent.
- Renderers
Write state configuration files in the language, templating engine, or file type of your choice. The world doesn't need yet another DSL.
- Full list of renderers
- YAML? JSON? Jinja? Mako? Wempy? Python? We got you covered. (And if we don't, new renderers are tiny and easy to write.)
- Renderers
- Salt states are only concerned with the ultimate highstate data structure. How you create that data structure isn't our business. Tweak a config option and use whatever you're most comfortable with.
Miscellaneous topics¶
Salt is many splendid things.
- File Server
- Salt can easily and quickly transfer files (in fact, that's how Salt States work). Even under load, files are chunked and served.
- Syndic
- A seamless master of masters. Scale Salt to thousands of hosts or across many different networks.
- Peer communication
- Allow minions to communicate amongst themselves. For example, configure one minion by querying live data from all the others. With great power comes great responsibility.
- Running Salt without root
- The Salt daemons can be run as an unprivileged user.
- Firewall settings and Salt
- A tutorial covering how to properly firewall a Salt Master server.
- Cron and Salt States
- A tutorial covering how to properly use cron to schedule when a minion updates its state.
- Network topology
- At it's core, Salt is a highly scalable communication layer built on top of ZeroMQ that enables remote execution and configuration management. The possibilities are endless and Salt's future looks bright.
- Testing Salt
- A howto for writing unit tests and integration tests.
- Python API interface
- Use Salt programmatically from your own scripts and programs easily and simply via import salt.
- 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 your minions running your latest builds.
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
- Dense but complete.
More information about the project¶
- Release notes
- Where we've been.
- Community
- How you can get involved.
