Puppet 5 Cookbook - Fourth Edition

Puppet 5 Cookbook - Fourth Edition

By : Thomas Uphill

Buy this Book

Puppet 5 Cookbook - Fourth Edition

By: Thomas Uphill

Buy this Book

Overview of this book

Puppet is a configuration management system that automates all your IT configurations, giving you control of managing each node. Puppet 5 Cookbook will take you through Puppet's latest and most advanced features, including Docker containers, Hiera, and AWS Cloud Orchestration. Updated with the latest advancements and best practices, this book delves into various aspects of writing good Puppet code, which includes using Puppet community style, checking your manifests with puppet-lint, and learning community best practices with an emphasis on real-world implementation. You will learn to set up, install, and create your first manifests with version control, and also learn about various sysadmin tasks, including managing configuration files, using Augeas, and generating files from snippets and templates. As the book progresses, you'll explore virtual resources and use Puppet's resource scheduling and auditing features. In the concluding chapters, you'll walk through managing applications and writing your own resource types, providers, and external node classifiers. By the end of this book, you will have learned to report, log, and debug your system.

Title Page

Packt Upsell

Contributors

Preface

Free Chapter

Puppet Language and Style

Introduction

Adding a resource to a node

Using facter to describe a node

Using puppet facts

Installing a package before starting a service

Installing, configuring, and starting a service

Using community Puppet style

Installing Puppet

Creating a manifest

Checking your manifests with puppet-lint

Making modules

Using standard naming conventions

Using inline templates

Iterating over multiple items

Writing powerful conditional statements

Using regular expressions in if statements

Using selectors and case statements

Using the in operator

Using regular expression substitutions

Puppet 5 changes

Puppet 4/5 changes

Puppet Infrastructure

Introduction

Managing your manifests with Git

Creating a decentralized Puppet architecture

Writing a papply script

Running Puppet from cron

Bootstrapping Puppet with bash

Creating a centralized Puppet infrastructure

Creating certificates with multiple DNS names

Setting up the environment

Configuring PuppetDB

Configuring Hiera

Environment-specific Hiera

Setting node-specific data with Hiera

Writing a custom Hiera5 function

Storing secret data with hiera-eyaml

Automatic syntax-checking with Git hooks

Pushing code around with Git

Managing environments with Git

Writing Better Manifests

Introduction

Using arrays of resources

Using resource defaults

Using defined types

Using tags

Using run stages

Using roles and profiles

Using data types in Puppet

Passing parameters to classes

Passing parameters from Hiera

Writing reusable, cross-platform manifests

Getting information about the environment

Importing dynamic information

Passing arguments to shell commands

Working with Files and Packages

Introduction

Making quick edits to config files

Editing INI-style files with puppetlabs-inifile

Using Augeas to reliably edit config files

Building config files using snippets

Using ERB templates

Using array iterations in templates

Using EPP templates

Using GnuPG to encrypt secrets

Comparing package versions

Users and Virtual Resources

Introduction

Using virtual resources

Managing users with virtual resources

Managing users' SSH access

Managing users' customization files

Using exported resources

Managing Resources and Files

Introduction

Distributing cron jobs efficiently

Scheduling when resources are to be applied

Using host resources

Using exported host resources

Using multiple file sources

Distributing and merging directory trees

Cleaning up old files

Auditing resources

Temporarily disabling resources

Managing Applications

Introduction

Using public modules

Managing Apache servers

Creating Apache virtual hosts

Creating NGINX virtual hosts

Managing MariaDB

Creating databases and users

Servers and Cloud Infrastructure

Introduction

Managing firewalls with iptables

Building high-availability services using Keepalived

Managing NFS servers and file shares

Using HAProxy to load balance multiple web servers

Managing EC2 instances

Managing virtual machines with Vagrant

Managing Docker with Puppet

External Tools and the Puppet Ecosystem

Introduction

Creating custom facts

Adding external facts

Setting facts as environment variables

Generating manifests with the Puppet resource command

Generating manifests with other tools

Using PDK

Using an external node classifier

Creating your own resource types

Creating your own providers

Creating custom functions

Testing your puppet manifests with rspec-puppet

Monitoring, Reporting, and Troubleshooting

Introduction

Noop—the don't-change-anything option

Logging the command output

Logging debug messages

Generating reports

Producing automatic HTML documentation

Drawing dependency graphs

Understanding Puppet errors

Inspecting configuration settings

Other Books You May Enjoy

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Distributing cron jobs efficiently

When you have many servers executing the same cron job, it's usually a good idea not to run them all at the same time. If all of the jobs access a common server (for example, when running backups), it may put too much load on that server, and even if they don't, all the servers will be busy at the same time, which may affect their capacity to provide other services.

How to do it...

Here's how to have Puppet schedule the same job at a different time for each machine:

Modify your site.pp file as follows:

node 'cookbook' {
  cron { 'run-backup':
    ensure  => present,
    command => '/usr/local/bin/backup',
    hour    => split($facts['ipaddress'],'\.')[3] % 24,
    minute  => '00',
  }
}

Run Puppet:

[root@cookbook ~]# puppet agent -t
...
Notice: /Stage[main]/Main/Node[cookbook]/Cron[run-backup]/ensure: created

Check crontab to see how the job has been configured:

# HEADER: This file was autogenerated at 2018-03-15 19:13:55 +0000 by puppet.
# HEADER:...

Puppet 5 Cookbook - Fourth Edition

By : Thomas Uphill

Puppet 5 Cookbook - Fourth Edition

By: Thomas Uphill

Overview of this book

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