www.it-ebooks.info Learning Nagios Learn how to set up Nagios in order to monitor your systems efficiently Wojciech Kocjan BIRMINGHAM - MUMBAI www.it-ebooks.info Learning Nagios Copyright © 2014 Packt Publishing All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews Every effort has been made in the preparation of this book to ensure the accuracy of the information presented However, the information contained in this book is sold without warranty, either express or implied Neither the author nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals However, Packt Publishing cannot guarantee the accuracy of this information First published: October 2008 Second Edition: March 2014 Production Reference: 1140314 Published by Packt Publishing Ltd Livery Place 35 Livery Street Birmingham B3 2PB, UK ISBN 978-1-78328-864-9 www.packtpub.com Cover Image by Francesco Langiulli (langy86@gmail.com) www.it-ebooks.info Credits Author Project Coordinator Wojciech Kocjan Kranti Berde Reviewers Proofreaders Péter Károly "Stone" Juhász Clyde Jenkins Emilien Kenler Lucy Rowland Daniel Parraz Indexer Pall Sigurdsson Hemangini Bari Acquisition Editors Anthony Albuquerque Nikhil Chinnari Graphics Ronak Dhruv Disha Haria Content Development Editor Yuvraj Mannari Chalini Victor Production Coordinator Technical Editors Pooja Chiplunkar Monica John Akashdeep Kundu Faisal Siddiqui Cover Work Pooja Chiplunkar Copy Editors Alisha Aranha Roshni Banerjee Brandt D'Mello Deepa Nambiar www.it-ebooks.info About the Author Wojciech Kocjan is a system administrator and programmer with 10 years of experience His work experience includes several years of using Nagios for enterprise IT infrastructure monitoring He also has experience in large variety of devices and servers, routers, Linux, Solaris, AIX servers and i5/OS mainframes His programming experience includes multiple languages (such as Java, Ruby, Python, and Perl) and focuses on web applications as well as client-server solutions I'd like to thank my wife Joanna and my son Kacper for all of the help and support during the writing of this book www.it-ebooks.info About the Reviewers Péter Károly "Stone" Juhász was born in 1980 in Hungary, where he lives with his family and their cat He holds an MSc degree in Programmer Mathematics At the very beginning of his career, he turned toward operations Since 2004, he has been working as a general—mainly GNU/Linux—system administrator His average working day includes patching in the server room, installing servers, managing PBX, maintaining VMware vSphere infrastructure and servers at Amazon AWS, managing storage and backups, monitoring with Nagios, trying out new technology, and writing scripts to ease everyday work His interests in IT are Linux, server administration, virtualization, artificial intelligence, network security, and distributed systems His hobbies include learning Chinese, program developing, reading, hiking, playing the game Go, listening to music and unicycling For his contact information or to find out more about him, you can visit his website at http://midway.hu Emilien Kenler, after working on small web projects, began to focus on Game Development in 2008, when he was in high school Until 2011, he worked for different groups and has specialized in system administration In 2011, he founded a company, HostYourCreeper (http://www.hostyourcreeper.com) to sell Minecraft servers, while he was studying Computer Science Engineering He created a lightweight IaaS based on new technologies such as Node.js and RabbitMQ Thereafter, he worked at TaDaweb as a system administrator, building its infrastructure and creating tools to manage deployments and monitoring In 2014, he began a new adventure at Wizcorp, Tokyo He will graduate at the end of the year from the University of Technology of Compiègne www.it-ebooks.info Daniel Parraz was raised in New Mexico and began using computer-type devices at an early age After graduating from school, he found a technical support job and started to learn Linux He has been administrating Linux/Unix systems since 2001 and has worked on large storage engineering and installations with Fortune 500 companies and start-ups He currently lives in Albuquerque, New Mexico, with his family, and enjoys hiking, reading, and growing fruits and vegetables as a volunteer with an agriculture group supported by a local community.  Pall Sigurdsson is a lifelong open source geek with special interest in automation and monitoring He is known for his work in developing Adagios, a modern web status, and a configuration interface to monitor systems that are compatible with Nagios Pall also maintains other projects such as Pynag (a high-level python API for Nagios configuration files) and okconfig (a set of preconfigured Nagios plugins and configuration templates) www.it-ebooks.info www.PacktPub.com Support files, eBooks, discount offers and more You might want to visit www.PacktPub.com for support files and downloads related to your book Did you know that Packt offers eBook versions of every book published, with PDF and ePub files available? 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PacktLib is Packt's online digital book library Here, you can access, read and search across Packt's entire library of books Why Subscribe? • Fully searchable across every book published by Packt • Copy and paste, print and bookmark content • On demand and accessible via web browser Free Access for Packt account holders If you have an account with Packt at www.PacktPub.com, you can use this to access PacktLib today and view nine entirely free books Simply use your login credentials for immediate access www.it-ebooks.info www.it-ebooks.info Table of Contents Preface 1 Chapter 1: Introducing Nagios Understanding the basics of Nagios The benefits of monitoring resources Main features 11 Soft and hard states 13 What's new in Nagios 4.0 14 Summary 16 Chapter 2: Installing Nagios 17 Installation 17 Upgrading from previous versions 18 Installing prerequisites 19 Obtaining Nagios 21 Setting up users and groups 22 Compiling and installing Nagios 24 Compiling and installing Nagios plugins 27 Setting up Nagios as a system service 30 Resolving errors with script for the Nagios system service 32 Configuring Nagios 34 Creating the main configuration file 34 Understanding macro definitions 38 Configuring hosts 41 Configuring host groups 44 Configuring services 46 Configuring service groups 50 Configuring commands 51 Configuring time periods 53 Configuring contacts 55 www.it-ebooks.info ... script for the Nagios system service 32 Configuring Nagios 34 Creating the main configuration file 34 Understanding macro definitions 38 Configuring hosts 41 Configuring host groups 44 Configuring... third-party plugins 140 Summary 141 Chapter 5: Advanced Configuration 143 Creating maintainable configurations 144 Configuring the file structure 145 Defining the dependencies 147 Creating the host.. .Learning Nagios Learn how to set up Nagios in order to monitor your systems efficiently Wojciech Kocjan BIRMINGHAM - MUMBAI www.it-ebooks.info Learning Nagios Copyright © 20 14 Packt Publishing