PSICK: Classify and manage with style

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This is the PSICK (Puppet Systems Infrastructure Construction Kit) module, a module than alone accomplishes a good slice of what you need to do with Puppet.

Example42's psick Puppet module provides the following features, all of which are optional:

  • Classification - Manage Puppet classification in a smart, staged, Hiera driven way.
  • A set of base profiles for common systems management needs on: Linux, MacOS and Windows.
  • Integration with the companion psick_profile module to manage multiple more or less common applications

The module is designed to:

  • Permit quick, safe and easy integration in any Puppet setup
  • Allow cherry picking of the desired functionalities and profiles
  • Be entirely Hiera driven: In practice a DSL to configure infrastructures

It can be used together with the PSICK control-repo or as a strandalone module, just classify it on your nodes:

include psick

By default, this doesn't do anything at all, but is enough to let you manage everything via Hiera, in the psick namespace.

In the following examples we will use Hiera YAML files, but any backend can be used: psick is a normal, even if somehow unusual, Puppet module, with classes (a lot of them) whose params can be set as Hiera data, defines, templates, files, fuctions, custom data types etc.

Check the default PSICK hiera data module for various real world usage examples.


Psick can manage the whole classification of the nodes of an infrastructure. It can work side by side and External Node Classifier, or it can totally replace it.

When used for classification, you just need to include the psick class on all your nodes (typically in manifests/site.pp) and then configure it via Hiera, considering that:

  • Different Hiera keys are available to manage the classes to include for different OSes at different stages of the classification
  • Psick has 4 classification stages, by default they require the previous one to be completed: First run (optional, executed only once), pre, main and profile.
  • Each Hiera key used to classify, has as value an hash of key values, where keys are strings used as placeholders, and values are the names of classes to include.

Example of Hiera data to classifiy Linux and Windows nodes:

# First run mode must be enabled and each class to include there explicitely defined:
psick::enable_firstrun: true
  hostname: psick::hostname
  packages: psick::aws::sdk
  hostname: psick::hostname
  packages: psick::aws::sdk

# Pre and base classes, both on Linux and Windows
  puppet: puppet
  dns: psick::dns::resolver
  hostname: psick::hostname
  hosts: psick::hosts::resource
  repo: psick::repo
  sudo: psick::sudo
  time: psick::time
  sysctl: psick::sysctl
  update: psick::update
  ssh: psick::openssh::tp
  mail: psick_profile::postfix
  mail: psick::users::ad

  hosts: psick::hosts::resource
  features: psick::windows::features
  registry: psick::windows::registry
  services: psick::windows::services
  time: psick::time
  users: psick::users::ad

# Profiles for specific roles (ie: webserver)
  webserver: apache
  webserver: psick_profile::iis

Psick base profiles

Psick provides ready to use profiles for many common OS configurations: users management, time, openssh, keys, cronjobs, sysctl, different languages setups (php, ruby, python...), motd, hosts file, common packages, proxy...

Refer to the specific documentation for more details. Here is some example Hiera data to manage uan user with admin powers, the dns resolver and some limits, according to the profile used:

# User al creation with ssh_authorized_keys:
    ensure: present
    comment: 'Al'
      - users
      - wheel
      - 'ssh-rsa AAAAB3NzaC...'
# Passwordless sudopowers for user al
    content: 'al ALL=(ALL) NOPASSWD:ALL'

# Example to manage resolver

# Sample Limits
    soft: 2048
    hard: 4096

psick_profile and applications profiles

For some very common applications and languages, there are dedicated profile classes and defines, in the psick and the psick_profile modules. Here's a list from psick:

Check the psick_profile module for more details.

Main variables and common parameters

The main psick class has some parameters which are used as defaults in all the psick and psick profile classes or can contain data (in Hashes of key-values) used by all the other psick profiless

You can use them as general switches or data sources which apply to psick and psick_profile classes.

Check for more details on the Main Parameters, here they are wit the default values:

# General psick switches
psick::manage: true
psick::auto_prereq: true
psick::noop_manage: false
psick::noop_value: false
psick::force_ordering: true

# Available data general enpoints
psick::settings: {}
psick::servers: {}
psick::tp: {}
psick::firewall: {}
psick::monitor: {}

Additional documentation

Check this list of blog posts about psick module: