Weaving with Light Pt. 1

This is the first in a series of posts regarding a recent project which integrated handweaving, fiber optics, and electronics. It’s a part of a costume for a cosplayer at work, but I’ll be discussing my part of it. TL;DR For those who can’t wait, here’s what the project looks like in the dark: And …

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Abusing HAProxy: Stupid Simple Easy Dashboards

I wanted a simple way to have a dashboard to show if hosts and services are alive & didn’t want to write much code and/or run up a nagios instance (or anything like that). All I care is whether it’s green or red. I’d already been setting up HAProxy for a proxy forwarder, so I …

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Rules for Operations

The following list was compiled in 2012 for a talk on Operations Principles for Developers (Ops4Devs). They are loosely inspired by the list of rules from Zombieland as well as from my experiences and those shared by others. Looking over the list four years later, I believe that they are still (very) applicable for all …

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DevOps Creed (Work in Progress)

This is a work in progress of a DevOps Creed. It will always be a work in progress as I and others learn and grow. Suggestions are welcome! I have drunk deep of the DevOps Kool-Aid. From the visions which ensued, I have come to the following…. I Believe: DevOps methodologies lead to systems which …

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I am not a Mindreader: a mini-saga

I must confess a severe failing on my part. I am not a mindreader. I am not privy to the thoughts in your head. I do not know your needs or desires. And I am certainly not aware of your expectations. This is why requirement documents exist. Please use them.

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Weaving with Light Pt. 1Abusing HAProxy: Stupid Simple Easy DashboardsRules for OperationsDevOps Creed (Work in Progress)I am not a Mindreader: a mini-saga

Sep 18

OBS for Videos

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I recently discovered a really interesting tool for producing videos of screen captures, optionally with webcam inserts. It’s called Open Broadcaster Software and it works on Linux, Windows, and there is a beta version for Apple OSX.

It seems that it was originally intended for streaming to websites, but it has a lot more features now. Within a few minutes I was able to set it up for Kidzilla and she’s been busy recording her drawing sessions so that she can upload speeddraw videos to youtube. Admittedly, they’ll need post-processing to speed them up, but still, it’s easy for her to use — we set up a hotkey for starting and stopping recording.

I expect to be using it myself very shortly, but so far I like it a lot!

Note for Linux Users

You might encounter an issue with recordings being black/blank, despite showing in the preview properly. After some searching I discovered: Black Screen fix.

Once I set it to do 32 sample down scaling it fixed it. Two of the options work but the default bicubic with 16 samples was causing the issue.

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Sep 14

Creating Mini Sagas

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howto, mini sagas

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sagaFirst start with an idea. It can be fiction or not. Then start to write. Write your story and then count the words. The goal is fifty words, no more, no less. Trim if need be, otherwise add words. Edit, rinse, repeat until you’re done. Publish it; write some more.

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Sep 12

Minimum Viable Configuration (a mini saga)

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devops, infrastructure, mini sagas, philosophy, rants

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Too many believe that bigger is better; elaborate systems, multitude layers, and diverse architectural patterns demonstrate a maturity of design. Unfortunately they aren’t called at 3am when it breaks.

I prefer the simplicity of less — kissing Occam’s razor; trimming away until perfection… when there is nothing left to take away.

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Sep 07

Bulk Adding Hosts to a Pi Swarm

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cloud, cloud computing, cloud-in-a-box, Docker, hypriot, Raspberry Pi, swarm, tips

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I’ve refreshed my stack and am rebuilding the cluster. I’m using Hypriot for the linux distribution, but I’m a smart sysadmin (read lazy) and don’t want to manually add them each time. Also, I want to make a script so that I can quickly rebuild.

This is inspired by Let Docker Swarm all over your Raspberry Pi Cluster. The Hypriot folk are most excellent people.

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Sep 07

Getting the Docker Swarm Discovery Token

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Docker, swarm, tips

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At the moment, docker swarm doesn’t have a self-discovery method. If you’ve mislaid or forgotten the discovery token you can’t add new elements. It just so happens that if you do a docker inspect $SWARM_AGENT_MASTER, the token will show up in the command line arguments.

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Sep 07

Viewing Raspberry Pi Config Variables and More

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howto, Raspberry Pi, tips

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Sometimes it’s helpful to see if a particular parameter is set or not on the raspberry pi. This is where vcgencmd. However, vcgencmd is useful for many other things.

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Sep 07

PDF-XChange Editor Review

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I was in training last week — rather than a printed text, we were provided with a PDF of the slides. PDF files are not the easiest thing to annotate without special software and, well, Adobe Acrobat isn’t precisely cheap.

I was very pleased to find Tracker Software’s PDF-XChange Editor. There is both a free and paid version of the software. For my purposes of adding notes to the slides, the free version is more than sufficient. It allows you to do the following (and much more!):

  • Highlight
  • Draw shapes and arrows
  • Add “Post-it” notes
  • Add text
  • Add boxes

The class was held on Windows; the Editor works very nicely on Windows. I haven’t gotten it to work on Linux, but haven’t spent more than 5 minutes on it. The previous version, the PDF Exchange Viewer, works under Wine, with one caveat. It crashes if you attempt to save the first PDF file opened. So, “mount a scratch monkey” (open a small pdf file which you then ignore) and subsequent files can be opened and edited. The editing tools in the Viewer are not quite as nice as the Editor, however, they’re more than sufficient for marking up and annotating PDF’s.

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Sep 07

Troubleshooting MicroSD Card Problems

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gotchas, howto, troubleshooting

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The Computer employs Troubleshooters, whose job is to go out, find trouble, and shoot it. — Paranoia

While re-imaging the MicroSD cards for my cluster, I ran into a few issues — nothing insurmountable, but I figured that I would share them to help others…..

MicroSD cards generally come with an adapter to allow them to be used in SD card slots. If there is a problem with the adapter, it can manifest in a few ways and cascade from there.

SD cards come with a switch which makes them read-only. However, if the switch is faulty, any MicroSD cards put in the adapter will not be writable.

foobar-sdcard

In this case, the slider was faulty and slid to the locked position when I put the card into the computer.

The next SD card adapter, while the write-only slider works, had other problems:

The adapter was bad in this case; consequently the device didn’t mount. This caused yet another issue. When the image was written to /dev/mmcblk0, it overwrote the mount point for the device.

Notice that mmcblk0 has -, which denotes it is a regular file. mmcblk0p1 is a block device as denoted by the b — these are disks and the like.

In order for the device to mount so that the card can be imaged, the file needs to be removed. After this, the automounter will work correctly and create the device when the card is inserted (with a good adapter, of course).

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Sep 03

Power Loss (a mini saga)

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mini sagas, rants

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Virtual presence doesn’t work too well when the power is out. It is hard to see in the dark and TCP/IP is pretty slow over semaphore or pigeon. The huddled masses hover over their phones and laptops, hoarding the last few precious voltamps of power, praying for Light’s return.

(Over 36K customers lost power in Columbus, OH today. Right in the middle of virtual training.)

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Sep 02

Times have Changed: Virtual Training

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miscellany

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I’m in hadoop admin training for ${WORK} this week — it’s a virtual course, but the interface is actually the nicest I’ve seen yet. The training is being held by ExitCertified and the virtual bit pretty much just works. They provide a webcam and headset to cut down on technical issues. So I have a monitor with a feed of the instructor or other people who are asking questions. Another monitor has the contents of his screen. Finally I’ve got a third one with sundries running in it. I’m really liking three monitors; it’s pretty useful.

Despite the instructor having live and virtual students, the interaction is actually quite nice. The current speaker pops up and the instructor can see us (and we can see each other!).

Having been an instructor in the past definitely informs my opinions. There is a lot which is lost when you’re not “face to face”.

“Virtual” training in the past has meant that you saw a webcast screen and spent eight hours on a conference call, this is much, much better!

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