HOW-TOs

Watermarking Images--from the Command Line

Us geeks mostly think of the command line as the best place for text manipulation. It's a natural with cat, grep and shell scripts. But although you can't necessarily view your results from within a typical terminal window, it turns out to be pretty darn easy to analyze and manipulate images from within a shell script.

Classifying Text

In my last few articles, I've looked at several ways one can apply machine learning, both supervised and unsupervised. This time, I want to bring your attention to a surprisingly simple—but powerful and widespread—use of machine learning, namely document classification.

Jmol: Viewing Molecules with Java

Let's dig back into some chemistry software to see what kind of work you can do on your Linux machine. Specifically, let's look at Jmol, a Java application that is available as both a desktop application and a web-based applet.

Integrating Web Applications with Apache

When you deploy a web application, how do end users access it? Often web applications are set behind a gateway device through which end users can access it. One of the popular products to act as an application gateway on Linux is the Apache Web Server. Although it can function as a normal web server, it also has the ability to connect through it to other web servers.

Manipulate Images with ImageMagick

In my last article, I had some fun looking at the children's game of rock, paper, scissors, writing a simple simulator and finding out that some strategies are better than others. Yes, I used "strategy" and "rock, paper, scissors" in the same sentence!

The Post-TV Age?

The most basic cable package from Charter (Spectrum?) costs me more than $70 per month, and that's without any equipment other than a single cable card. It's very clear why people have been cutting the cord with cable TV companies. But, what options exist? Do the alternatives actually cost less? Are the alternatives as good?

Unsupervised Learning

In my last few articles, I've looked into machine learning and how you can build a model that describes the world in some way. All of the examples I looked at were of "supervised learning", meaning that you loaded data that already had been categorized or classified in some way, and then created a model that "learned" the ways the inputs mapped to the outputs.

Sysadmin 101: Automation

This is the second in a series of articles on systems administrator fundamentals. These days, DevOps has made even the job title "systems administrator" seem a bit archaic, much like the "systems analyst" title it replaced. These DevOps positions are rather different from sysadmin jobs in the past.

Postmortem: What to Do After a Security Incident

Incidents happen. Vulnerabilities happen. The quality of your response can make the difference between a bad day and a disaster. What happens after the response can make the difference between endless firefighting and becoming stronger with every battle. A quality postmortem analysis is free ammunition.

Managing Docker Instances with Puppet

In a previous article, "Provisioning Docker with Puppet", in the December 2016 issue, I covered one of the ways you can install the Docker service onto a new system with Puppet. By contrast, this article focuses on how to manage Docker images and containers with Puppet.

Scissors, Paper or Rock?

In this article, I'm going to tackle a children's game that's extraordinarily complicated, with many variations, and the programming task is going to be quite tricky. Just kidding! Rock Paper Scissors (or RPS, as it's known) is pretty darn easy to simulate because there aren't really many variants or possible outcomes.

Sysadmin 101: Alerting

This is the first in a series of articles on system administrator fundamentals. These days, DevOps has made even the job title "system administrator" seem a bit archaic, much like the "systems analyst" title it replaced.

The Current Phase of the Moon

Ladies and gentlemen, we've left Mars. Well, at least I'm done with the Martian lander from my past few articles. I hope you had chance to experiment with it and find out that it's not too easy to land a craft on any planet!

Mastering ATA over Ethernet

At one point in time, when you wanted to attach an external block storage device to a server, you mapped it as a Logical Unit (LU) across a Storage Area Network (SAN). In the early days, you would do this over the Fibre Channel (FC) protocol. More recently, iSCSI (SCSI over IP) has usurped FC in most data centers.

The Family Dashboard

I've written a little about PHP before, because I think it's a great utility language for writing quick things you need to do. Plus, it allows you to use a web browser as your interface, and everyone has a web browser. That makes it very convenient for my family, because I can make simple web interfaces for the various things I normally have to do from the command line.

Adding IoT Flare to a Hot Springs and Spa Business

As the folks at Bozeman Hot Springs usher their hot springs and spa into the 21st century with new technology and pools, they are thinking about new ways to delight their customers and stay top of mind. One recurring request, no doubt from the avid skiing community, is the ability to read current pool temperatures online, in the same way ski resorts publish current snow conditions.

Orchestration with MCollective

I originally got into systems administration because I loved learning about computers, and I figured that was a career that always would offer me something new to learn. Now many years later that prediction has turned out to be true, and it seems like there are new things to learn all the time.

Graph Any Data with Cacti!

For the past few years, I've been trying to understand how to make graphs using RRDtool (Round-Robin Database tool) after failing miserably to understand MRTG (Multi-Router Traffic Grapher) before that. The thing I like about RRDtool is that it's newer and supports a wider variety of data sources.

Preparing Data for Machine Learning

When I go to Amazon.com, the online store often recommends products I should buy. I know I'm not alone in thinking that these recommendations can be rather spooky—often they're for products I've already bought elsewhere or that I was thinking of buying. How does Amazon do it?