SSH TUNNELS AND ENCRYPTED VIDEO STREAMING ™ WATCH: ISSUE OVERVIEW V APRIL 2016 | ISSUE 264 LinuxJournal.com Since 1994: The Original Magazine of the Linux Community + STUNNEL Intro to Pandas The Python Data Analysis SECURITY Library for Databases A Look at printf A Super- Protect Useful Scripting Your Desktop Command Environment What’s the with Qubes Kernel Space of Democracy? BE SMART ABOUT CREATING A SMART HOME LJ264-April2016.indd 1 3/22/16 10:12 AM NEW! Self-Audit: Agile Checking Product Assumptions Development at the Door Practical books Author: Author: Ted Schmidt for the most technical Greg Bledsoe Sponsor: IBM Sponsor: people on the planet. HelpSystems Improve Finding Your Business Way: Mapping Processes with Your Network an Enterprise to Improve !""#$!%&'"( Job Scheduler Manageability Author: Author: Mike Diehl Bill Childers Sponsor: Sponsor: Skybot InterMapper DIY Combating Commerce Site Infrastructure Sprawl Author: Reuven M. Lerner Author: Sponsor: GeoTrust Bill Childers Sponsor: Puppet Labs Download books for free with a Get in the Take Control simple one-time registration. Fast Lane of Growing with NVMe Redis NoSQL http://geekguide.linuxjournal.com Author: Server Clusters Mike Diehl Author: Sponsor: Reuven M. Lerner Silicon Mechanics Sponsor: IBM & Intel LJ264-April2016.indd 2 3/22/16 10:12 AM NEW! Self-Audit: Agile Checking Product Assumptions Development at the Door Practical books Author: Author: Ted Schmidt for the most technical Greg Bledsoe Sponsor: IBM Sponsor: people on the planet. HelpSystems Improve Finding Your Business Way: Mapping Processes with Your Network an Enterprise to Improve !""#$!%&'"( Job Scheduler Manageability Author: Author: Mike Diehl Bill Childers Sponsor: Sponsor: Skybot InterMapper DIY Combating Commerce Site Infrastructure Sprawl Author: Reuven M. Lerner Author: Sponsor: GeoTrust Bill Childers Sponsor: Puppet Labs Download books for free with a Get in the Take Control simple one-time registration. Fast Lane of Growing with NVMe Redis NoSQL http://geekguide.linuxjournal.com Author: Server Clusters Mike Diehl Author: Sponsor: Reuven M. Lerner Silicon Mechanics Sponsor: IBM & Intel LJ264-April2016.indd 3 3/22/16 10:12 AM APRIL 2016 CONTENTS ISSUE 264 FEATURES 86 Rock-Solid 100 Stunnel Security Encrypted for Oracle Video Streaming Improve database security Using SSH with Stunnel. Tunnels and the Charles Fisher BeagleBone Black ON THE COVER Learn how SSH tunnels work :[\UULS:LJ\YP[`MVY+H[HIHZLZW by setting up a remote )L:THY[HIV\[*YLH[PUNH:THY[/VTLW ::/;\UULSZHUK,UJY`W[LK=PKLV:[YLHTPUNW viewable Webcam on your 7YV[LJ[@V\Y+LZR[VW,U]PYVUTLU[^P[O8\ILZW BeagleBone Black. 0U[YV[V7HUKHZ[OL7`[OVU+H[H(UHS`ZPZ3PIYHY`W (3VVRH[WYPU[M!H:\WLY<ZLM\S:JYPW[PUN*VTTHUKW Ramon Crichlow >OH[Z[OL2LYULS:WHJLVM+LTVJYHJ`&W 4 | April 2016 | LinuxJournal.com LJ264-April2016.indd 4 3/22/16 10:12 AM CONTENTS COLUMNS 34 Reuven M. Lerner’s At the Forge Pandas 42 Dave Taylor’s Work the Shell All about printf 50 Kyle Rankin’s Hack and / Secure Desktops with Qubes: Introduction 60 Shawn Powers’ The Open-Source Classroom Jarvis, Please Lock the Front Door 120 Doc Searls’ EOF 24 What’s the Kernel Space of Democracy? IN EVERY ISSUE 8 Current_Issue.tar.gz 10 Letters 16 UPFRONT 32 Editors’ Choice 76 New Products 125 Advertisers Index 60 LINUX JOURNAL (ISSN 1075-3583) is published monthly by Belltown Media, Inc., PO Box 980985, Houston, TX 77098 USA. Subscription rate is $29.50/year. Subscriptions start with the next issue. 5 | April 2016 | LinuxJournal.com LJ264-April2016.indd 5 3/22/16 9:06 PM Executive Editor Jill Franklin [email protected] Senior Editor Doc Searls [email protected] Associate Editor Shawn Powers [email protected] Art Director Garrick Antikajian [email protected] Products Editor James Gray [email protected] Editor Emeritus Don Marti [email protected] Technical Editor Michael Baxter [email protected] Senior Columnist Reuven Lerner [email protected] Security Editor Mick Bauer [email protected] Hack Editor Kyle Rankin lj@greenfly.net Virtual Editor Bill Childers [email protected] Contributing Editors )BRAHIM (ADDAD s 2OBERT ,OVE s :ACK "ROWN s $AVE 0HILLIPS s -ARCO &IORETTI s ,UDOVIC -ARCOTTE 0AUL "ARRY s 0AUL -C+ENNEY s $AVE 4AYLOR s $IRK %LMENDORF s *USTIN 2YAN s !DAM -ONSEN President Carlie Fairchild [email protected] Publisher Mark Irgang [email protected] Associate Publisher John Grogan [email protected] Director of Digital Experience Katherine Druckman [email protected] Accountant Candy Beauchamp [email protected] Linux Journal is published by, and is a registered trade name of, Belltown Media, Inc. 0/ "OX (OUSTON 48 53! Editorial Advisory Panel Nick Baronian Kalyana Krishna Chadalavada "RIAN #ONNER s +EIR $AVIS -ICHAEL %AGER s 6ICTOR 'REGORIO $AVID ! ,ANE s 3TEVE -ARQUEZ $AVE -C!LLISTER s 4HOMAS 1UINLAN #HRIS $ 3TARK s 0ATRICK 3WARTZ Advertising % -!),: [email protected] 52,: www.linuxjournal.com/advertising 0(/.% EXT Subscriptions % -!),: [email protected] 52,: www.linuxjournal.com/subscribe -!), 0/ "OX (OUSTON 48 53! LINUX IS A REGISTERED TRADEMARK OF ,INUS 4ORVALDS LJ264-April2016.indd 6 3/22/16 10:12 AM !"#$%&'%#$%()*%+#,%-.'/0 With Drupal 8 newly released and thousands of community members in attendance, DrupalCon New Orleans promises to be an event to remember. See you in New Orleans this May. Laissez les Bon Temps Rouler! neworleans2016.drupal.org LJ264-April2016.indd 7 3/22/16 10:12 AM Current_Issue.tar.gz Linux Does Stuff SHAWN ERE HUGE FANS OF OPEN SOURCE HERE AT POWERS Linux Journal, which I’m sure comes as no SURPRISE TO ANYONE 4HE BEST PART ABOUT Shawn Powers is the W Associate Editor for ,INUX ITSELF HOWEVER IS THAT ITS THE CONCEPT OF OPEN Linux Journal. He’s SOURCE REALIZED )T HAS PERMEATED EVERY ASPECT OF )4 also the Gadget Guy AND IT HAS PROVEN THAT BEING OPEN DOESNT EQUATE TO for LinuxJournal.com, and he has an BEING INSECURE )N FACT ITS QUITE THE OPPOSITE 7HEN interesting collection you have nothing to hide, there aren’t any dirty secrets of vintage Garfield WAITING TO BE LEAKED )N THE SPIRIT OF hDOING THINGSv coffee mugs. Don’t let his silly hairdo THIS MONTH WEVE GOT A BUNCH OF REALLY COOL TOPICS fool you, he’s a that show open source in action. pretty ordinary guy 7E START WITH 2EUVEN - ,ERNER ,AST MONTH HE and can be reached via e-mail at talked about navigating data, and this month he talks [email protected]. ABOUT 0ANDAS 3PECIFICALLY 2EUVEN TALKS ABOUT PARSING Or, swing by the AND ANALYZING #36 COMMA SEPARATED VALUES FILES #linuxjournal IRC channel on WITH 0YTHON )F YOURE A DATA NERD AND WANT TO GET Freenode.net. THE MOST FROM YOUR #36 DATA FILES YOU WONT WANT TO MISS 2EUVENS COLUMN THIS ISSUE $AVE 4AYLOR FOLLOWS WITH A LOOK AT SOME POWERFUL SCRIPTING COMMANDS V BORROWED FROM THE # LIBRARY )F YOU WANT TO TIGHTEN YOUR CODE THE PRINTF COMMAND IS INCREDIBLY POWERFUL VIDEO: AND THANKFULLY AVAILABLE FOR SCRIPTING Shawn +YLE 2ANKIN KEEPS HIS SECURITY HEAD FIRMLY IN PLACE Powers runs AND STARTS A SERIES ON 1UBES THIS MONTH 1UBES IS A through DISTRIBUTION FOCUSED ON SECURITY 7ITH ALL THE PUBLICITY the latest issue. encryption and privacy is getting thanks to the Apple/FBI case, it’s important to understand how 8 | April 2016 | LinuxJournal.com LJ264-April2016.indd 8 3/22/16 10:12 AM Current_Issue.tar.gz SECURITY ON YOUR DEVICES FUNCTIONS +YLE STARTS HIS SERIES BY DESCRIBING HOW 1UBES COMPARTMENTALIZES APPLICATIONS ISOLATING THEM FROM EACH OTHER AND THE /3 ITSELF 7HETHER OR NOT YOU WANT TO BEEF UP YOUR DESKTOP SECURITY HIS ARTICLE IS A FASCINATING LOOK AT AN AWESOME TECHNOLOGY ) GO IN A VERY DIFFERENT DIRECTION THIS MONTH AND RATHER THAN TALK ABOUT SECURITY ) FOCUS ON WHAT SOMETIMES CAN BE THE OPPOSITE OF security—convenience. I’ve always wanted a smart house, and thanks TO 3MART4HINGS AND THE !MAZON %CHO ) FINALLY HAVE ONEOR AT LEAST THE START OF ONE )F YOUVE EVER WANTED TO TALK TO YOUR HOUSE LIKE IT WAS THE computer on the Starship Enterprise, you’ll want to check out my column. 33( IS ARGUABLY MY FAVORITE COMMAND LINE TOOL IN ,INUX )TS SECURE and it’s so versatile. Ramon Crichlow explains how to stream video securely through an SSH tunnel this month. Not only will you learn how to accomplish a cool video streaming task, but along the way, you’ll learn a lot about how SSH works and what tunneling really means. You’ll also LEARN HOW TO TWEAK IT SO ITS NOT MORE FRUSTRATING THAN USEFUL #HARLES &ISHER FOLLOWS 2AMON WITH A VERY IN DEPTH LOOK AT USING STUNNEL AS A TOOL FOR AUTHENTICATION ISOLATION AND PRIVACY OF DATA STORED IN AN /RACLE DATABASE )F YOUVE EVER MANAGED AN /RACLE DATABASE AND HAD CONCERNS ABOUT ITS SECURITY IMPLEMENTATIONS EVEN CONSIDERING RECENT IMPROVEMENTS USING THE OPEN SOURCE STUNNEL TOOL CAN ADD A SOLID LAYER OF SECURITY THAT IS REGULARLY UPDATED AND OFFERS THE PEACE OF MIND THAT COMES WITH &/33 7HETHER YOU WANT TO IMPROVE THE SECURITY OF YOUR DESKTOP ENVIRONMENT USE ,INUX AS A TOOL TO ACCOMPLISH A NECESSARY FUNCTION OR JUST TURN ON YOUR BEDROOM LIGHTS BY TALKING TO A 0RINGLES CAN SHAPED ROBOT THIS MONTH IS AN ISSUE WORTH READING !S ALWAYS ITS ALSO FULL OF PRODUCT ANNOUNCEMENTS TIME SAVING TIPS AND OTHER ,INUX RELATED GOODIES 7HETHER THIS IS YOUR FIRST ISSUE OF Linux Journal OR YOUVE BEEN ONE OF US FOR YEARS WE HOPE YOU enjoy this issue as much as we enjoyed putting it together.Q Send comments or feedback via http://www.linuxjournal.com/contact or to [email protected]. RETURN TO CONTENTS 9 | April 2016 | LinuxJournal.com LJ264-April2016.indd 9 3/22/16 10:12 AM LETTERS[ LETTERS ] PREVIOUS NEXT V V Current_Issue.tar.gz UpFront Dave Taylor’s Article on getopt 2EGARDING $AVE 4AYLORS h7ORKING WITH #OMMAND !RGUMENTSv IN THE &EBRUARY ISSUE ITS A WORTHY ARTICLE BUT LETS EXPAND ON IT A BIT Long arguments like !!"#$% certainly deserve a mention.