Terraform cheat sheet

October 6th, 2019

The course “Infrastructure Automation With Terraform” provides the course files on github: “wardviaene/terraform-course“.

Print whole deep object in JS

October 6th, 2019

The functions `console.log` or `JSON.stringify` in JavaScript do not print deep nested structures. To workaround, use `util.inspect`:

const util = require('util')
console.log(util.inspect(object_to_dump, { depth: 100, compact: false }))

Minimal GF-RGL usage example

April 4th, 2019

I managed to run GF-RGL (see the previous post) as a part of a third-party project gf-matrix. Then I modified gf-matrix grammar files to create a minimal working version. Here is the result:

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Running GF-RGL

March 29th, 2019

The GF Resource Grammar Library is the standard library for Grammatical Framework. It covers the morphology and basic syntax of over 30 languages. The GF project is big, and it is hard for outsiders to start using GF-RGL. This post summarizes my first steps which can be repeated by others.

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Multi-page table with inter-row page breaks

March 3rd, 2019

Usually it is a bad idea to break table inside a row. But people do want it. Once I sketched a quick dirty hack for latex cals package and since then I’ve got several support requests. It seems now I have to support the code.

The current version can be found as github gist: tblbrk.tex.

Cleaning the signal from EEG-SMT

September 30th, 2017

An disappointment after getting EEG-SMT working: the resulting measurement is just a noice. It is a challenging task for a beginner to understand what is going wrong.

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Display signal from OpenEEG EEG-SMT

September 10th, 2017

There is a number of software intended for EEG works. The EEG-SMT quick start guide suggests Electric Guru, BrainBay and OpenVibe, but it implies the use of a legacy operating system instead of Linux.

This post extends the quick start to have Linux notes. The content:

* Install OpenVIBE
* Connect STM-EEG to Linux
* Configure OpenVIBE
* Get the signal

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Affordable EEG and neurofeedback: OpenEEG, EEG-SMT

September 9th, 2017

My old interest is to influece the brain to make it working more efficient.

One of the approaches is to learn complete relaxation, or in other word meditation. The book “Meditation für Skeptiker” by Ulrich Ott suggests a scientific evidence for this claim, and I decided to try.

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Format dvd+rw before writing data

August 13th, 2017

Writing a DWD+RW under Linux should be simple, something like:

$ wodim speed=2 dev=/dev/sr0 -v -data ubuntu-16.04.3-desktop-i386.iso

However, in my case it fails. Some background knowledge suggests to format the disc first, but blanking the disc fails too.

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AWS response status is always 200

July 29th, 2017

There is a task, which can’t be avoided when developing serverless applicatoins on Amazon Web Services:

How to return a custom status code from a REST API?

One of the approaches is to use “prefix mapping”, like for example is shown in this amazon blog post: Error Handling Patterns in Amazon API Gateway and AWS Lambda by Bryan Liston.

The only problem is that the approach doesn’t always work. After a long debuggin session with many false tries, I’ve found the reason.

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mocking microservices for functional tests

February 4th, 2017

Here are a few links which helped me to understand what to use to mock microservices with REST API. Just for a case, I’ve choosen wiremock because I need Java and saboteur functionality.

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python Selenium in Ubuntu 16.04

December 22nd, 2016

Selenium is a web browser automation software. In Ubuntu 16.04 it doesn’t work out of the box, and external components should be installed. In this post I note how to install them locally without affecting the system.

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experience report with TDD

November 3rd, 2016

I’ve seriously tried TDD in a real project, writing tests before code and following the red-green-refactor cycle. Short summary:

* I believe in TDD now;
* training and practice are required to learn TDD, reading books is not enough;
* the initial time investment is big.

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how to move anything in rviz in ros

October 26th, 2016

Rviz A 3d visualization environment for robots. Sounds intriguing and useful, but the first steps in it are painful. In particular, moving anything is surprisingly a very hard task for a novice who doesn’t know about the right way. Now I have enough experience to describe what to do: Moving things in rviz.

vi editing mode set global

October 18th, 2016

The Linux command line and other software based on readline library support vi editing mode. After I worked on a new system with the default settings for a while, I noticed that I miss this mode very much.

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fast throw-away git repository

August 22nd, 2016

Based on the article How to Run Your Own Git Server, I’ve constructed a small list for fast git setup for temporary projects.

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DANTE e.V. Frühjahrstagung 2016

April 20th, 2016

I was a speaker at the TeX users meeting in Wuppertal, with the talk “Erfahrung und Vorhersagen für automatisches XML-nach-PDF-Publizieren mit TeX” (experience and prediction for automatical from-XML-to-PDF publishing using TeX).

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python libxml2 dita

January 21st, 2016

python libxml2 dita

For correct transformation of DITA files (XML-standard for modular documentation), it is necessary to pull information from DTD (document type definition). In my python code, sometimes I did get this information and sometimes not. Now I’ve tracked the source of instability and corrected the code.

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Printing unusually sized PDFs

December 21st, 2015

The PDF is of some non-standard landscape layout, the printer is an usual A4 printer, the software can’t handle the mix correctly. The solution is to tune the dimensions of the PDF pages manually.

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le-tex transpect: how to use docbook-to-docx stylehseets

December 10th, 2015

For XML to DocBook to .docx conversion, I found that “le-tex transpect” framework has solved many technical issues already, so I overcame the “not invented here syndrome” and decided to rely on this tool. To tune the stylesheets for own needs, I created a github copy of the repository: docxtools. To run the stylesheets outside the framework, a special setup is required. The setup is described in the folder “doc/hello-world“.