Python network programming cookbook

Python Network Programming Cookbook, Second Edition 2017 is his first book as an author, and he is quite excited about it... to work on the Google Summer of Code 2009/2010 programs forco

Python Network Programming Cookbook

Second Edition

Overcome real-world networking challenges

Pradeeban Kathiravelu

Dr M O Faruque Sarker

BIRMINGHAM - MUMBAI

Python Network Programming Cookbook

Second Edition

Copyright © 2017 Packt Publishing

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Every effort has been made in the preparation of this book to

ensure the accuracy of the information presented However, theinformation contained in this book is sold without warranty, eitherexpress or implied Neither the authors, nor Packt Publishing, andits dealers and distributors will be held liable for any damages

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Packt Publishing has endeavored to provide trademark informationabout all of the companies and products mentioned in this book bythe appropriate use of capitals However, Packt Publishing cannotguarantee the accuracy of this information

First published: March 2014

Second edition: August 2017

About the Author

Pradeeban Kathiravelu is an open source evangelist He is a

Ph.D researcher at INESC-ID Lisboa/Instituto Superior Tecnico,Universidade de Lisboa, Portugal, and Universite Catholique deLouvain, Belgium He is a Fellow of Erasmus Mundus Joint

Degree in Distributed Computing (EMJD-DC), researching a

software-defined approach to quality of service and data quality inmulti-tenant clouds

Pradeeban holds a master of science degree, Erasmus Mundus

European Master in Distributed Computing (EMDC), from

Instituto Superior Tecnico, Portugal and KTH Royal Institute ofTechnology, Sweden He also holds a first class bachelor of science

in engineering (Hons) degree, majoring in computer science andengineering, from the University of Moratuwa, Sri Lanka His

research interests include Software-Defined Networking (SDN),distributed systems, cloud computing, web services, big data inbiomedical informatics, Network Functions Virtualizations (NFV),and data mining He is very interested in free and open source

software development and has been an active participant in the

Google Summer of Code (GSoC) program since 2009, as a studentand as a mentor

Pradeeban has published several conference papers and

co-authored a few book chapters He has also worked on

OpenDaylight Cookbook and Learning OpenDaylight as a technical

reviewer Python Network Programming Cookbook, Second

Edition (2017) is his first book as an author, and he is quite excited

about it

I would like to thank my readers for the interest in the book Please feel free to contact me if you need any assistance in the topics or the recipes, beyond what we have discussed in the book I would like to thank the entire editorial team at Packt, including Abhishek Jadhav, Rahul Nair, and Mohd Riyan Khan I would like to extend

my thanks to the Linux Foundation for their open source projects

on softwarization of networks and systems I would like to thank my friends and colleagues who helped me in various ways I would like

to thank Prof Luis Veiga (INESC-ID Lisboa), my MSc and Ph.D advisor, for sharing his wisdom and encouragement throughout my stay in Instituto Superior Tecnico I would like to thank him for being my mentor since 2012 I would also like to thank Prof Ashish Sharma (Emory University, Atlanta) for his guidance and

motivation.

My special thanks go to my loving wife, Juejing Gu This book

would not be a reality without her continuous support and creative suggestions Her tireless efforts helped me always be on time

without missing the deadlines.

I would like to thank my mom, Selvathie Kathiravelu, for her

support.

Dr M O Faruque Sarker is a software architect based in

London, UK, where he has been shaping various Linux and opensource software solutions, mainly on cloud computing platforms,for commercial companies, educational institutions, and

multinational consultancies Over the past 10 years, he has beenleading a number of Python software development and cloud

infrastructure automation projects In 2009, he started using

Python, where he was responsible for shepherding a fleet of

miniature E-puck robots at the University of South Wales,

Newport, UK Later, he honed his Python skills, and he was invited

to work on the Google Summer of Code (2009/2010) programs forcontributing to the BlueZ and Tahoe-LAFS open source projects.

He is the author of Python Network Programming Cookbook and

Learning Python Network Programming both by Packt Publishing.

He received his Ph.D in multi-robot systems from the University

of South Wales He is currently working at University CollegeLondon He takes an active interest in cloud computing, softwaresecurity, intelligent systems, and child-centric education He lives

in East London with his wife, Shahinur, and daughter, Ayesha

All praises and thanks to Allah, the God who is the Merciful and the Beneficent I would not be able to finish this book without the help of God.I would like to thank everyone who has contributed to the publication of this book, including the publisher, technical

reviewers, editors, my family and friends for their sacrifice of time, encouraging words, and smiles, especially my wife Shahinur

Rijuani for her love and support in my work I also thank the

readers who have patiently been waiting for this book and who have given me lots of valuable feedback.

About the Reviewers

Dr S Gowrishankar is currently working as an associate

professor in the Department of Computer Science and Engineering

at Dr Ambedkar Institute of Technology, Bengaluru, Karnataka,India

He received his Ph.D in Engineering from Jadavpur University,Kolkata, West Bengal, India in 2010, MTech in softwareengineering and BE in computer science and engineering fromVisvesvaraya Technological University (VTU), Belagavi,Karnataka, India in the year 2005 and 2003 respectively

From 2011 to 2014 he worked as a senior research scientist andtech lead at Honeywell Technology Solutions, Bengaluru,Karnataka, India

He has published several papers in various reputed internationaljournals and conferences He is serving as an editor and reviewerfor various prestigious international journals He is also a member

of IEEE, ACM, CSI, and ISTE

He has delivered many keynote addresses and invited talksthroughout India on a variety of subjects related to computerscience and engineering He was instrumental in organizing severalconferences, workshops, and seminars He has also served on thepanel of a number of academic bodies of universities andautonomous colleges as a BOS and BOE member

His current research interests are mainly focused on data science,including its technical aspects as well as its applications and

implications Specifically, he is interested in the applications ofMachine Learning, Data Mining, and Big Data Analytics inHealthcare.

I would like to acknowledge my earnest gratitude to my wife,

Roopa K M, for her constant source of support and encouragement throughout this assignment I'm truly thankful to almighty God for having her in my life and give her my deepest expression of love and appreciation.

Michael Bright, RHCE/RHCSA, is a solution architect working in

the HPE EMEA Customer Innovation Center

He has strong experience across Cloud and Container technologies(Docker, Kubernetes, AWS, GCP, Azure) as well as NFV/SDN

Based in Grenoble, France, he runs a Python user group and is aco-organizer of the Docker and FOSS Meetup groups He has akeen interest in Container, Orchestration, and Unikernel

technologies on which he has presented and run training tutorials inseveral conferences

He has presented many times on subjects diverse as NFV, Docker,Container Orchestration, Unikernels, Jupyter Notebooks,

MongoDB, and Tmux

Michael has a wealth of experience across pure research, R&D andpre-sales consulting roles

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valuable feedback Help us be relentless in improving our products!

I dedicate this book to the world, in memory of my dad,

Kanapathipillai Kathiravelu.

Table of Contents

Preface

What this book covers

What you need for this book

Who this book is for

Sections

Getting ready How to do it…

How it works…

There's more…

See also Conventions

Reader feedback

Customer support

Downloading the example code Downloading the color images of this book Errata

Piracy Questions

1 Sockets, IPv4, and Simple Client/Server Programming

Writing a simple UDP echo client/server application

How it works

Waiting for a remote network service

How to do it

How it works

Sending web requests through a proxy server

Getting ready How to do it

Writing a simple HTTPS server code with Python and OpenSSL Getting ready

How to do it

How it works

Building asynchronous network applications with Twisted

Getting ready How to do it

How it works

Building asynchronous network applications with Tornado

Getting ready How to do it

How it works

Building concurrent applications with Tornado Future

Getting ready How to do it

How it works

Common error Uploading a local file to a remote FTP server

Getting ready How to do it

Getting ready How to do it

How it works

Checking your remote email with IMAP

Getting ready How to do it

How it works

Writing a simple SMTP server

Getting ready How to do it

How it works

Writing a secure SMTP client using TLS

Getting ready How to do it

How it works

Writing an email client with POP3

Getting ready How to do it

How it works

6 Programming Across Machine Boundaries

Executing a remote shell command using telnet

Getting ready How to do it

How it works

Copying a file to a remote machine by SFTP

Getting ready How to do it

How it works

Printing a remote machine's CPU information

Getting ready How to do it

How it works

Installing a Python package remotely

Getting ready How to do it

How it works

Running a MySQL command remotely

Getting ready How to do it

How it works

Transferring files to a remote machine over SSH

Getting ready How to do it

How it works

Configuring Apache remotely to host a website

Getting ready How to do it

Getting ready How to do it

How it works

Saving packets in the pcap format using the pcap dumper

How to do it

How it works

Emulating networks with Mininet

Getting ready How to do it

How it works

Distributed network emulation with MaxiNet

Getting ready How to do it

How it works

Emulating wireless networks with Mininet-WiFi Getting ready

How to do it

How it works

Extending Mininet to emulate containers

Getting ready How to do it

How it works

Developing Software-Defined Networks with OpenDaylight contro ller

Getting ready How to do it

How it works

Developing Software-Defined Networks with POX controller

Getting ready How to do it

How it works

Developing Software-Defined Networks visually with MiniEdit

Getting ready How to do it

How it works

Finding DNS host information

Getting ready How to do it

How it works

Finding DNS resource records

Getting ready How to do it

How it works

Making DNS zone transfer

Getting ready How to do it

How it works

Querying NTP servers

Getting ready How to do it

How it works

Connecting to an LDAP server

Getting ready How to do it

How it works

Making LDAP bind

Getting ready How to do it

How it works

Reading and writing LDAP

Getting ready How to do it

How it works

Authenticating REST APIs with Eve

Getting ready How to do it

How it works

Configuring OpenContrail cluster

How it works

Packet processing with DPDK

Getting ready How to do it

How it works

Parsing BMP messages with SNAS.io

Getting ready How to do it

How it works

14 Programming the Internet

Introduction

Checking a website status

Getting ready How to do it

Looking glass implementations with Python

Getting ready How to do it

How it works

It has been more than 3 years since Python Network Programming

Cookbook was first published In this second edition, we extend our

book to discuss the recent advancements in the networking industryand network softwarization The widespread use of Software-

Defined Networking (SDN), Network Functions Virtualization(NFV), and orchestration have been addressed in detail in the latterchapters while the first eight chapters were taken from the first

edition, improved with a few new recipes based on the feedbackfrom the readers

This book is an exploratory guide to network programming in

Python It has touched a wide range of networking protocols such

as TCP/UDP, HTTP/HTTPS, FTP, SMTP, POP3, IMAP, and CGI.With the power and interactivity of Python, it brings joy and fun todevelop various scripts for performing real-world tasks on networkand system administration, web application development,

interacting with your local and remote network, low-level networkpacket capture and analysis, and so on The primary focus of thisbook is to give you a hands-on experience on the topics covered

So, this book covers less theory, but it is packed with practical

materials

This book is written with a DevOps mindset, where a developer isalso more or less in charge of operation, that is, deploying the

application and managing various aspects of it, such as remote

server administration, monitoring, scaling-up, and optimizing forbetter performance This book introduces you to a bunch of open-source, third-party Python libraries, which are ideal to be used in

various use cases We elaborate in detail the configurations ofcomplex networking systems with helpful hints to ensure that thereader can follow them without getting stuck.

We hope you will enjoy the recipes presented in this book andextend them to make them even more powerful and enjoyable

What this book covers

Chapter 1, Sockets, IPv4, and Simple Client/Server Programming,

introduces you to Python's core networking library with varioussmall tasks and enables you to create your first client-server

application

Chapter 2, Multiplexing Socket I/O for Better Performance,

discusses various useful techniques for scaling your client/serverapplications with default and third-party libraries

Chapter 3, IPv6, Unix Domain Sockets, and Network Interfaces,

focuses more on administering your local machine and lookingafter your local area network

Chapter 4, Programming with HTTP for the Internet, enables you to

create a mini command-line browser with various features such assubmitting web forms, handling cookies, managing partial

downloads, compressing data, and serving secure content over

HTTPS

Chapter 5, Email Protocols, FTP, and CGI Programming, brings

you the joy of automating your FTP and e-mail tasks such as

manipulating your Gmail account, and reading or sending emailsfrom a script or creating a guest book for your web application Welearn to write email clients with SMTP and POP3

Chapter 6, Programming Across Machine Boundaries, gives you a

taste of automating your system administration and deploymenttasks over SSH You can run commands, install packages, or set upnew websites remotely from your laptop