Salt 🧂

Salt is a powerful tool for configuration management and automation. It allows you to manage servers by executing commands on various operating systems, including almost all common Linux distributions, the BSD family, and Windows.

Here’s a simple example of how to use Salt:

salt <Minion Name> pkg.upgrade

This command upgrades all installed packages on the managed systems, regardless of whether they use apt, yum, pacman, or zypper. In addition to running commands, you can also define custom configurations using YAML syntax to specify the desired state of a system.

To use Salt effectively, it’s helpful to understand some key terms. Salt works on a classic master-minion model. The master acts as the central authority, holding the configurations that are stored in what are called States. The minion is the managed system that executes the instructions from the master.

There are two basic interaction models:

Pull model: The minion actively fetches commands from the master.
Push model: The master sends commands to the minions.

Salt Master

The master sets the direction and manages the instructions for the minions. By default, these configurations are stored under /srv/salt/. Alternatively, you can set up a Git integration, but make sure to use GitPython as the gitfs provider, not pygit2.

Installation (Example for Debian 10) You can check the Salt Repo for how to install Salt Master on various systems.

Here’s a quick overview of how to install it on Debian 10 (as root):

Download and add the GPG key:

wget -O - https://repo.saltstack.com/py3/debian/10/amd64/latest/SALTSTACK-GPG-KEY.pub | apt-key add -

Add the SaltStack repository:

deb http://repo.saltstack.com/py3/debian/10/amd64/latest buster main

Update the package lists:
```
apt-get update
```
Install the Salt Master:
```
apt-get install salt-master
```

Salt Minion

The minion is the managed system where commands are executed. Its main configuration file is located at /etc/salt/minion, where the master server is defined. By default, the master is set to salt, but this can be adjusted depending on your network environment.

Installation (Example for Debian 10)

As with the master, you can find installation instructions in the Salt Repo for various systems.

Download and add the GPG key:

wget -O - https://repo.saltstack.com/py3/debian/10/amd64/latest/SALTSTACK-GPG-KEY.pub | apt-key add -

Add the SaltStack repository:

deb http://repo.saltstack.com/py3/debian/10/amd64/latest buster main

Update the package lists:
```
apt-get update
```
Install the Salt Minion:
```
apt-get install salt-minion
```
Adjust the configuration if needed.
Restart the service:
```
systemctl restart salt-minion
```

Salt States

Salt States are like blueprints for a system. They describe the desired state of a machine—what programs should be installed, what configurations should be applied, etc. These instructions are written in YAML. The minion fetches these “blueprints” from the master and executes them.

Salt Grains

Grains are system properties of the minions, such as the operating system (os) or the virtualization type (virtual). To list all grains for a host, you can use:

salt '*' grains.ls

To see the values of the grains:

salt '*' grains.items

Salt Pillar

Pillars are key-value stores primarily used for sensitive information like passwords or API keys. Unlike grains, pillars are not directly executed on the minions; they are only provided by the master.

Conclusion 🎉

Salt provides a powerful platform for managing diverse systems. With its push-and-pull architecture, the ability to create simple or complex configurations, and broad operating system support, it is an indispensable tool for automation in modern IT environments.

Further Resources

The official Salt documentation.

Feel free to reach out via email, LinkedIn, or GitHub if you have any comments, suggestions, or questions!