Python for Unix and Linux System Administration

458 Pages·2008·3.42 MB·English

by  Noah Gift

Python for Unix and Linux System
Administration
,roadmapgeneric.14718 Page ii Friday, August 8, 2008 11:43 AM
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main.title Page iii Monday, May 19, 2008 11:21 AM
Python for Unix and LinuxT Soymstceamt
™
TAhde mDeifinniistitvrea Gtuioidne
JaNsoona hB rGititfat iann adn Jde rIeamn yF .M D.a Jrowniens
Beijing • Cambridge • Farnham • Köln • Sebastopol • Taipei • Tokyo
Python for Unix and Linux System Administration
by Noah Gift and Jeremy M. Jones
Copyright © 2008 Noah Gift and Jeremy M. Jones. All rights reserved.
Printed in the United States of America.
Published by O’Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472.
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Printing History:
August 2008: First Edition.
Nutshell Handbook, the Nutshell Handbook logo, and the O’Reilly logo are registered trademarks of
O’Reilly Media, Inc. Python for Unix and Linux System Administration, the image of a boa constrictor,
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While every precaution has been taken in the preparation of this book, the publisher and authors assume
no responsibility for errors or omissions, or for damages resulting from the use of the information con-
tained herein.
ISBN: 978-0-596-51582-9
[M]
1218651032
I dedicate this book to Dr. Joseph E. Bogen,
my mom, and my wife, Leah—three people who
have loved me and believed in me when it counted
the most.
—Noah
I dedicate this book to my wife, Debra, and my
children, Zane and Justus. You encouraged me,
bore with me with great patience, and gave me
many smiles along the journey of writing this
book. This book is as much yours as it is mine.
—Jeremy

Table of Contents
Foreword ................................................................... xi
Preface .................................................................... xiii
1. Introduction ............................................................ 1
Why Python? 1
Motivation 6
The Basics 8
Executing Statements in Python 8
Using Functions in Python 12
Reusing Code with the Import Statement 16
2. IPython ............................................................... 21
Installing IPython 22
Basic Concepts 23
Help with Magic Functions 30
Unix Shell 34
Information Gathering 51
Automation and Shortcuts 64
Summary 69
3. Text .................................................................. 71
Python Built-ins and Modules 71
Log Parsing 110
ElementTree 116
Summary 120
4. Documentation and Reporting ........................................... 123
Automated Information Gathering 123
Manual Information Gathering 126
Information Formatting 135
vii
Information Distribution 141
Summary 145
5. Networking .......................................................... 147
Network Clients 147
Remote Procedure Call Facilities 158
SSH 164
Twisted 167
Scapy 173
Creating Scripts with Scapy 175
6. Data ................................................................. 177
Introduction 177
Using the OS Module to Interact with Data 178
Copying, Moving, Renaming, and Deleting Data 179
Working with Paths, Directories, and Files 181
Comparing Data 185
Merging Data 187
Pattern Matching Files and Directories 193
Wrapping Up rsync 195
Metadata: Data About Data 197
Archiving, Compressing, Imaging, and Restoring 199
Using tarfile Module to Create TAR Archives 199
Using a tarfile Module to Examine the Contents of TAR Files 201
7. SNMP ................................................................ 205
Introduction 205
Brief Introduction to SNMP 205
IPython and Net-SNMP 208
Discovering a Data Center 211
Retrieving Multiple-Values with Net-SNMP 214
Creating Hybrid SNMP Tools 220
Extending Net-SNMP 222
SNMP Device Control 224
Enterprise SNMP Integration with Zenoss 225
8. OS Soup .............................................................. 227
Introduction 227
Cross-Platform Unix Programming in Python 228
PyInotify 238
OS X 240
Red Hat Linux Systems Administration 245
Ubuntu Administration 245
viii | Table of Contents
Solaris Systems Administration 245
Virtualization 246
Cloud Computing 247
Using Zenoss to Manage Windows Servers from Linux 253
9. Package Management ................................................. 257
Introduction 257
Setuptools and Python Eggs 258
Using easy_install 258
easy_install Advanced Features 261
Creating Eggs 266
Entry Points and Console Scripts 270
Registering a Package with the Python Package Index 271
Distutils 273
Buildout 275
Using Buildout 276
Developing with Buildout 279
virtualenv 279
EPM Package Manager 283
10. Processes and Concurrency .............................................. 289
Introduction 289
Subprocess 289
Using Supervisor to Manage Processes 298
Using Screen to Manage Processes 300
Threads in Python 301
Processes 313
Processing Module 313
Scheduling Python Processes 316
daemonizer 318
Summary 321
11. Building GUIs ......................................................... 323
GUI Building Theory 323
Building a Simple PyGTK App 324
Building an Apache Log Viewer Using PyGTK 326
Building an Apache Log Viewer Using Curses 330
Web Applications 334
Django 335
Conclusion 354
12. Data Persistence ...................................................... 357
Simple Serialization 357
Table of Contents | ix