Reading recommendations (2016-10-08)

Posted on Sat 08 October 2016 in reading recommendations

While I wait for feedback on the draft for Sensu plugin documentation that I wrote I have some new reading recommendations. I'm also working on two more substantial articles but those are not polished enough yet for publication.

The "Have I been pwned" API rate limit has been brought forward - here's why by Troy Hunt ( feed)
This extremely useful service was first abused, then attacked by what can only be assumed to be criminals. Fortunately Hunt had already been preparing to implement a rate limit anyway and just had to speed up his efforts.

With VR mode, Dead or Alive goes from creepy to harassment by Allegra Frank ( feed)
One of the first not-so-great VR activities.

True Tales from Localization Hell by Bob Mackey (probably Twitter, possibly cross-reference from other article)
Localizing games is a challenging activity. Not only have do the texts have to be translated, but there are also restrictions in place, for example the amount of space available for the text or whether phrases need to end on a vowel or consonant.

Safety is not our first priority by ~smspillaz ( feed)

Every day we hear of a new data leak. Confidential information is stolen and sold to the highest bidder. Lives are meddled with and lives are ruined.

#BLAUGUST2016: FOOD by ~Syl ( feed)
Sometimes the best posts on gaming blogs are not even related to video games. Here's a nice one on eating habits instead.

Thanks for everything! The case for gratitude at work by Juli Fischer ( feed)
I make a point of being thankful at work because it's an easily visible sign that I respect my coworkers. This post goes into detail on methods that an organization can use to nurture a culture of gratitude. I especially like the wall of post-its.

Instapaper is joining pinterest by The Instapaper Team ( feed)
I am concerned by this acquisition. Usually in today's tech world that means the product will be sunset in 18 months tops. Though I dislike Safari's Reading List feature, I dislike Pocket even more, so Reading List it is. I have a hard time putting my trust into Instapaper. Good thing I started this blog mini-series to save the most interesting articles somewhere else. :)

This time the one link from the archives is Matt Gemmell's Ideology in which he makes a bold statement about violent reactions to terrorism, bombardments and hatred. He wrote this moving piece as reaction to the terrorist attacks in Paris in 2015.


Reading recommendations (2016-09-29)

Posted on Thu 29 September 2016 in reading recommendations

Between trying to figure out why one of our servers at work keeps insisting its RAID storage controller disappears after a few days of work and researching file exchange platforms like Syncthing, Owncloud and Seafile I've been quite busy for a while. I've also played more Black Desert and watched quite a lot of Star Wars: The Clone Wars on Netflix.

Fear of a Female President by Peter Beinart (via Twitter)
Misogeny waves abound even - or respectively especially - in the case of Clinton winning the elections and becoming the first female US president.

Software Application Risks on the OSX Continuum by The Cyber Independent Testing Lab (via Twitter)
Firefox on macOS is abysmal, Google Chrome is great (as expected). Microsoft's auto updater is evil personified while Apple's Software Update for the OS itself is quite good.

Trump campaign says media should not be ‘fact-checkers’ by Samantha Page (via Twitter)
Let me rephrase that: Trump campaign prefers not being told they blatantly lie on camera.

All Summer in a Day by Ray Bradbury (PDF, via Twitter)
A story to show you exactly how awful children can be.

Someone Is Learning How to Take Down the Internet by Bruce Schneier
Interesting theory about testing the Internet's "weak points" and how much pressure they can endure.

Not Your Grandmother's Meatball by Marissa Landrigan (browsing on
I found this short history of the American Meatball used in their Spaghetti most enjoyable. It depicts nicely how food can change and develop according to the circumstances of the demographic of its cooks.

Die armen Kinder vom Silicon Valley by Moritz Aisslinger (probably via Twitter, German)
I did not expect the difference between rich and poor in what I would call the global IT capital to be this extreme.

Bonus from the archive: Why we made Mattermost an open source Slack-alternative by The Mattermost Team is a enlightening, medium-length tale of how this software came to be.


I updated older posts with newer tech (August 2016)

Posted on Sun 28 August 2016 in work • Tagged with Institute for Computer Vision and Computer Graphics

I've taken some time today to update my system operations related posts with newer information. This information is based on the usage and issues that we faced and will hopefully prevent others from stumbling into the same problems should they choose to follow my guidance.

Reading recommendations (2016-08-24)

Posted on Wed 24 August 2016 in reading recommendations

This time I had to dump quite a lot of links into the sidenotes since it's been longer since the last post. But that's how it is given that I really want to adhere to my self-imposed 7 big links rule.

  • On Cybersecurity and Being Targeted by Kenneth Reitz (via Twitter)
    Reitz describes an attack on his person via GitHub and his DNS provider. The short lesson here is to use common e-mail provider when registering with services instead of a small one or your own. Two factor authentication helps.
  • Behind the Scenes of iOS Security by Ivan Krstic (via feed and others, presentation video)
    It's been a long time since Apple presented at a hacker congress. Krstic discusses iOS encryption, encryption for iCloud Keychain and introduces Apple's invite-only bug bounty program.
  • Sunday Conversation: Games That Made You Cry by Mark Delaney ( feed)
    While this article is focused on Xbox games I have fond memories of playing Grandia where I cried at the sweet and peaceful conclusion of its epic journey.
  • Germany to tell people to stockpile food and water in case of attacks: FAS by Caroline Copley, Andrew Bolton ( World News feed)
    I don't really know what to say here. I'm shocked. The post makes it sound as if Germany is preparing for war. Not that it is. I mean, probably not. Hopefully. It might be a precaution in case a city is in a state of emergency again as it was during the Munich shooting.
  • EquationGroup Tool Leak – ExtraBacon Demo by ~XORcat (via Twitter)
    Experiment with the leaked NSA tools. Technical read.
  • Twitter timeline about inciting hatred against the press at one of Trump's rallies by Jared Yates Saxton (curated by @EndTrumpsHate, via feed)
    Yes, another Trump link. This one shows the disgusting inciting of hatred towards press.
  • Notes from a lecture about C by Nick P (via feed)
    Haven't seen the presentation itself yet, but the notes about the design process of C are both enlightening and amusing.

Despite the self-restraint stated above, I've elected to include one gem from my archives which I'd like to add to these posts slowly until the archive is drained and I've fully switched to the Reading Recommendation posts.

"On Nerd Entitlement" by Laurie Penny is a fascinating read about how nerds who were shunned can in turn be no better than their tormentors by shunning women who don't adhere to the typical pretty woman stereotypes. I really can't stress how important it is for one to have a moment of introspection from time to time.


Sensu widget for Übersicht

Posted on Thu 18 August 2016 in work

Initially I was on the look for an alternative to Geektool for macOS that would not crash if I was to run an interactive script like iftop. When I saw that StatusCake report widget by Colin O'Brien for an HTML based Geektool alternative called Übersicht and saw that it was just processing some JSON I felt the urge to build something like that widget for our Sensu monitoring.

A few hours of research, cursing and reconfiguring systems I had a working solution even though my Javascript is still awful and I still don't know what's so great about CoffeeScript.

I've based my widget on O'Brien's and also provide my copy under the MIT License. I've commented functions and parameters for readability's sake. Yes, the changed colors might seem unnecessary but I took them straight from the Uchiwa interface for Sensu for consistency.

You can easily toggle on or off:

  • Sorting the events by hostname (default: true - I can't see why you wouldn't do that)
  • Display of the command run by Sensu that triggered this event (default: false)
  • Display of the output run of the failed check (default: true)
  • Blinking of certain indicators by warning level (default: [] - I hate the blinking but since it was already in the base I chose to support it anyway)


minimal version

no extra features enabled

only output

Only output enabled

only command

Only command enabled

everything enabled

All features enabled


SENSU_PASSWORD = "password"
SENSU_USERNAME = "username"
SENSU_URL = "https://sensu.domain.example:port"

# display options

# blink indicators - possible values: "warn", "error", "unknown"
# e.g. BLINKING_INDICATORS = ["warn", "error"]

command: "curl -sS --user #{SENSU_USERNAME}:#{SENSU_PASSWORD} #{SENSU_URL}/events"
refreshFrequency: 60000  # Milliseconds between calls

render: -> """
    @-webkit-keyframes blink {
       from { opacity: 1; }
       to { opacity: 0.2; }


update: (output, domEl) ->
  # Redraw the widget
  events = JSON.parse(output)
  table = $(domEl).find('table')


  translateStatus = (code) ->
    # translate between text and Sensu/Nagios status codes
    if code == 0
      return "ok"
    if code == 1
      return "warn"
    if code == 2
      return "error"
      return "unknown"

  showCommand = (check) ->
    # display the check command if enabled
    if check.command? and SHOW_COMMAND == true
      return "<= " + check.command
      return ""

  showOutput = (check) ->
    # display the check output if enabled
    if check.output? and SHOW_OUTPUT == true
      return "=> " + check.output
      return ""

  showBlinking = (status) ->
    # blink indicators if enabled
    if "warn" in BLINKING_INDICATORS and status == 1
      return "blink"
    if "error" in BLINKING_INDICATORS and status == 2
      return "blink"
    if "unknown" in BLINKING_INDICATORS and status != 0
      return "blink"
      return ""

  insertNewline = () ->
    # dynamically insert a newline between check command and check output if both are enabled
    if SHOW_OUTPUT == true and SHOW_COMMAND == true
      return "<br>"
      return ""

  sortByHostname = (a, b) ->
    # sort the results by hostname if enabled

  renderEvent = (event) ->
    # render one event
      <td class="status #{translateStatus(event.check.status)} #{showBlinking(event.check.status)}"><div class="disc"></div></td>
      <td class="sitename">#{}</td>
      <td class="check">#{} </td>
      <td class="impact">#{showCommand(event.check)}#{insertNewline()}#{showOutput(event.check)}\</td>

  if SORT_BY_HOSTNAME == true
    results = events.sort(sortByHostname)

  for event in events
    table.append renderEvent(event)

style: """
top: 20px
left: 80px
right: 80px
color: #ffffff
margin: 0 auto
font-family: Helvetica Neue, Sans-serif
font-smoothing: antialias
font-weight: 300
font-size: 16px
line-height: 27px


  padding: 8px 9px 0 0

.sitename, .check
  padding: 0 20px 0 0

  width: 12px
  height: 12px
  border-radius: 50%

.warn .disc
  background-color: rgba(249,186,70,1)

.error .disc
  background-color: rgba(234,84,67,1)

.unknown .disc
  background-color: rgba(77,77,77,1)

  animation: blink 2s cubic-bezier(0.950, 0.050, 0.795, 0.035) infinite alternate


  • I recommend using an additional layer of protection in front of your Sensu API (e.g. Apache/Nginx Basic Auth + Fail2ban)
  • I have not tested this with a Sensu which has no currently failing checks.
  • Please excuse me protecting the privacy of our servers in the screenshots :)