Leonid Shirmanov shirmanov

Using Vagrant with Multi-Node MicroK8S to experiment with Kubernetes

This script (using Vagrant) is used to build a pair of Ubuntu based virtual machines that have the MicroK8S setup of Kubernetes.

It also installs docker, and sets up aliases for kubectl in line with the MicroK8S documentation.

Please note that this script relies on the fact that Vagrant transfers files in /vagrant to the host file system, which we can then use to setup the second node.

Using Vagrant with MicroK8S to experiment with Kubernetes

This Virtual Machine (using Vagrant) to build an Ubuntu based virtual machine that has the MicroK8S setup of Kubernetes.

It also installs docker, and sets up aliases for kubectl in line with the MicroK8S documentation.

Initially this should be functionally similar to MiniKube.

If you want a multi-node similar environment, here's a similar repository.

I'm buiding a command line tool in Go that has an option to install itself as a service on Windows, which it needs admin rights for. I wanted to be able to have it reliably detect if it was running as admin already and if not, relaunch itself as admin. When the user runs the tool with the specific switch to trigger this functionality (-install or -uninstall in my case) they are prompted by UAC (User Account Control) to run the program as admin, which allows the tool to relaunch itself with the necessary rights.

To detect if I was admin, I tried the method described here first:
https://coolaj86.com/articles/golang-and-windows-and-admins-oh-my/
This wasn't accurately detecting that I was elevated, and was reporting that I was not elevated even when running the tool in CMD prompt started with "Run as Administrator" so I needed a more reliable method.

I didn't want to try writing to an Admin protected area of the filesystem or registry because Windows has the ability to transparently virtualize those writes

I heard some points of criticism to how React deals with reactivity and it's focus on "purity". It's interesting because there are really two approaches evolving. There's a mutable + change tracking approach and there's an immutability + referential equality testing approach. It's difficult to mix and match them when you build new features on top. So that's why React has been pushing a bit harder on immutability lately to be able to build on top of it. Both have various tradeoffs but others are doing good research in other areas, so we've decided to focus on this direction and see where it leads us.

I did want to address a few points that I didn't see get enough consideration around the tradeoffs. So here's a small brain dump.

"Compiled output results in smaller apps" - E.g. Svelte apps start smaller but the compiler output is 3-4x larger per component than the equivalent VDOM approach. This is mostly due to the code that is usually shared in the VDOM "VM" needs to be inlined into each component. The tr

Introduction

I was recently asked to explain why I felt disappointed by Haskell, as a language. And, well. Crucified for crucified, I might as well criticise Haskell publicly.

First though, I need to make it explicit that I claim no particular skill with the language - I will in fact vehemently (and convincingly!) argue that I'm a terrible Haskell programmer. And what I'm about to explain is not meant as The Truth, but my current understanding, potentially flawed, incomplete, or flat out incorrect. I welcome any attempt at proving me wrong, because when I dislike something that so many clever people worship, it's usually because I missed an important detail.

Another important point is that this is not meant to convey the idea that Haskell is a bad language. I do feel, however, that the vocal, and sometimes aggressive, reverence in which it's held might lead people to have unreasonable expectations. It certainly was my case, and the reason I'm writing this.

Type classes

I love the concept of type class

Here's a step by step guide to convert a Virtualbox .ova to a Vagrant box.

List your VMs to find the VM id you want to convert:

$ VBoxManage list vms
"testing" {a3f59eed-b9c5-4a5f-9977-187f8eb8c4d4}

You can now package the .ova VM as Vagrant box:

	@echo off
	title Microsoft Office 2019 versions are supported!&cls&echo
	============================================================================&echo
	#Project: Activating Microsoft software products for FREE without software&echo
	============================================================================&echo.&echo
	#Supported products:&echo - Microsoft Office Standard 2019&echo - Microsoft Office Professional Plus 2019&echo.&echo.&(if exist
	"%ProgramFiles%\Microsoft Office\Office16\ospp.vbs" cd /d "%ProgramFiles%\Microsoft Office\Office16")&(if exist
	"%ProgramFiles(x86)%\Microsoft Office\Office16\ospp.vbs" cd /d "%ProgramFiles(x86)%\Microsoft Office\Office16")&(for /f %%x in ('dir /b
	..\root\Licenses16\ProPlus2019VL*.xrm-ms') do cscript ospp.vbs /inslic:"..\root\Licenses16\%%x" >nul)&(for /f %%x in ('dir /b
	..\root\Licenses16\ProPlus2019VL*.xrm-ms') do cscript ospp.vbs /inslic:"..\root\Licenses16\%%x" >nul)&echo.&echo

	import ec2 = require('@aws-cdk/aws-ec2');
	import cdk = require('@aws-cdk/core');

	import { Fn, Tag, Resource } from '@aws-cdk/core';
	import { AmazonLinuxImage, UserData, InstanceType } from '@aws-cdk/aws-ec2';
	import { Role, ServicePrincipal, ManagedPolicy, CfnInstanceProfile } from '@aws-cdk/aws-iam'

	/**
	* Create my own Ec2 resource and Ec2 props as these are not yet defined in CDK
	* These classes abstract low level details from CloudFormation

	@echo off
	echo Deleting HKEY_CLASSES_ROOT\dacdchfile ...
	reg delete HKEY_CLASSES_ROOT\dacdchfile /f
	echo Deleting HKEY_CLASSES_ROOT\tigans ...
	reg delete HKEY_CLASSES_ROOT\tigans /f