Issue #219, July 2012
I thought we'd gone native this month and were going to show how to work nets and fish like the penguins do. I had a double-fisted, sheep-shanked, overhand cinch loop to teach you, along with the proper way to work your net in a snow storm. As it turns out though, it's actually the "networking" issue. That's still pretty cool, but instead of the half hitch, you get a crossover cable, and instead of my constrictor knot, you get load balancing.
Reuven M. Lerner starts out the issue with an article on Pry. If you're a Python programmer using iPython, you'll want to check out its Ruby counterpart, Pry. Although it's not required for coding with Ruby, it makes life a lot easier, and Reuven explains why. With a similar goal of improving your programming skills, Dave Taylor shows how to use subshells in your scripting. This doesn't mean you can't continue to write fun scripts like Dave's been demonstrating the past few months, it just means Dave is showing you how to be more efficient scripters. His tutorial is a must-read.
I got into the networking theme myself this month with a column on Webmin. Some people consider managing a server with Webmin to be a crutch, but I see it as a wonderful way to learn system administration. It also can save you some serious time by abstracting the underlying nuances of your various server types. Besides, managing your entire server via a Web browser is pretty cool. Speaking of "pretty cool", Kyle Rankin finishes his series on 3-D printing this issue. The printer itself is only half the story, and Kyle explains all the software choices for running it.
If Webmin seems a little light for your networking desires, perhaps Ratheesh Kannoth's article on the reconnaissance of the Linux network stack is more up your alley. Ratheesh peels back the mystery behind what makes Linux such a powerful and secure kernel, and does it using UML. If that sounds confusing, don't worry; he walks you through the entire process.
If you're actually creating or tweaking a network application, Andreas Petlund's article on TCP thin-stream modifications will prove invaluable. Anyone who ever has been fragged by an 11-year-old due to network latency knows a few milliseconds can be critical. Certainly there are other applications that rely on low network latency, but few are as pride-damaging as that. Andreas shows how to tweak some settings in the kernel that might make the difference between fragging or getting fragged. Unfortunately, no amount of tweaking can compare with the fast reflexes of an 11-year-old—for that you're on your own.
Stewart Walters picks up his OpenLDAP series from the April issue, and he demonstrates how to manage replication in a heterogeneous authentication environment. OpenLDAP is extremely versatile, but it still runs on hardware. If that hardware fails, a replicated server can make a nightmare into a minor inconvenience. You won't want to skip this article.
If my initial talk of fishing nets, knots and the high seas got you excited, fear not. Although this issue isn't dedicated to fish-net-working, my friend Adrian Hannah introduces the PirateBox. If the Internet is too commonplace for you, and you're more interested in dead drops, secret Wi-Fi and hidden treasure, Adrian's article is for you. The PirateBox doesn't track users, won't spy on your family and won't steal your dog. What it will do is share its digital contents to anyone in range. If your interest is piqued, check out Adrian's article and build your own. Yar!
This issue focuses on networking, but like every month, we try hard to include a variety of topics. Whether you're interested in Doc Searls' article on personal data or want to read new product and book announcements, we've got it. If you want to compare your home network setup with other Linux Journal readers, check out our networking poll. Perhaps you're in the market for a cool new application for your Linux desktop. Be sure to check out our Editors' Choice award for the app we especially like this month. Cast out your nets and reel in another issue of Linux Journal. We hope you enjoy reading it as much as we enjoyed putting it together.