The Power of Free

When I was a kid, I saved my money for weeks in order to buy the Aerobie. I lived in a ghetto of Detroit, and during the summer, we often would play Frisbee in the street for entertainment. I figured if I could buy the Aerobie, we'd be able to play Frisbee across multiple blocks! It would be amazing! So I hunted pop cans for weeks (in Michigan, pop can returns are 10 cents each), and finally I saved enough money to buy one. I took it home and tossed it down the street. And it kept going. I suspect it's still going, 30 years later. It flew down the street, over a block of houses and became a tiny dot in the sky. I never saw it again. Thankfully, unlike Aerobie buyers, it doesn't cost anything to start a brand-new project with Linux! We can install our operating system without worrying about license fees or saving up pop can money—and that means we aren't limited in the cool things we can do!

Reuven M. Lerner starts off the issue with an informative article on PostgreSQL 9.5. Relational databases might seem old-school, but what they do, they do very well. Reuven describes some of the cool new features of 9.5. Next up, Dave Taylor explains how to solve programming problems with the wegrep tool. Manipulating text via script is both incredibly fun and often very frustrating. (That frustration is part of the fun, if I'm being completely honest.) If you're a scripter who deals with text, you won't want to miss Dave's column.

Kyle Rankin continues his Qubes series this month. He described the setup last month, and conceptually how it works, and here he covers the multi-VM model for doing actual computing. The technologies in Qubes aren't brand new, but the way of using them certainly is. Even if you're not interested in the level of security Qubes offers, you owe it to yourself to read his series if only to understand the thought process itself. It's pretty unique!

I started my column this month with a simple problem: e-mail. Now that cloud computing is the norm, it means the servers you spin up aren't in your network anymore, and so might be blocked from using your ISP's SMTP server. There are certainly ways to set up an e-mail server that you can use for proper e-mail routing, but I just need a way to send quick-and-dirty server notification messages to myself when something goes wrong. I use Postfix and Gmail to accomplish that task, and I figured I'd share my experience.

Susan Sons is back this month with a brilliant article on securing your source code, at the source! It's great to have your revision control system secured and reliable, but what if the computer you actually use to develop gets compromised? That's a bigger concern than you might realize, and Susan walks through dealing with the often overlooked problem.

We follow Susan's column with Todd A. Jacobs' tutorial on how to implement YubiKey 4 for USB token-based authentication. I have a YubiKey myself, and I have never gotten around to using it for anything more than a conversation piece. If you're looking for a way to secure your systems, but want something more than two-factor authentication, be sure to read his article. It's surprising how powerful a simple little USB device can be when used in concert with Linux.

Finally, John S. Tonello shows how to build the Internet (well, maybe not quite the Internet, but a smaller version of it for learning purposes). The free nature of Linux means you can create an elaborate and dynamic network infrastructure without worrying about licensing fees. In Part I of John's series, he begins the process of building a server farm that will in many ways function like a tiny little Internet. If you're interested in world domination, building your own Internet is a great start!

This issue is full of our regular selection tech tips, product announcements and lots of interesting information for anyone interested in Linux. The coolest part is that all our projects run on Linux, which won't cost you anything at all (unlike an Aerobie). That said, if you try to throw your Linux laptop over houses in Detroit, much like the Aerobie, you'll never get it back—at least not in the same condition as when you tossed it!

Available to Subscribers: May 1