jlollis

Kubernetes and Arm

Getting rke and Rancher setup to run kubernetes on arm is interesting. There is no official support yet via rancher, although there is interest and some work done towards those efforts. This is my attempt at getting a cluster of 3 Pis (2 3Bs and 1 3B+) provisioned and registered to a rancher 2 server.

Prep

I've successfully completed this both with Hypriot OS 1.9.0 and the arm64 builds https://github.com/DieterReuter/image-builder-rpi64 Both times I used the same basic cloud-init setup

Credit: Mark Kraus
Website: https://get-powershellblog.blogspot.com

Collection Type Guidence

When to use what

Use Arrays if you know the element types and have a fixed length and/or known-up-front collection size that will not change.
Use ArrayList if you have an unkown collection size with either unknown or mixed type elements.
Use a Generic List when know the type of the elements but not the size of the collection.
Use a HashTable if you are going to do key based lookups on a collection and don't know the object type of the elements.
Use a Dictionary<TKey, TValue> you are going to do key based lookups on a collection and you know the type of the elements.
Use a HashSet when you know the type of elements and just want unique values and quick lookups and assignmnets.

ANNOUNCEMENT

I have moved this over to the Tech Interview Cheat Sheet Repo since a gist is too difficult to maintain as an open source endevaor and there is no way to version it. I have updated below, but I will not be able to keep this one up to date so please checkout the repo instead. The below is just for some preservation for those who stumble across here.

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Blockchain Course

These are the notes that I have taken on “IBM blockchain Essentials for Developers” course on Coursera IBM Blockchain Foundation for Developers | Coursera.

Jargon

Ledger: the system of record for a business

Transaction: an asset transfer onto or off the ledger

Rails Models

Generating models

$ rails g model User

Associations

belongs_to

has_one

	#!/bin/bash
	#####################################################
	# Name: Bash CheatSheet for Mac OSX
	#
	# A little overlook of the Bash basics
	#
	# Usage:
	#
	# Author: J. Le Coupanec
	# Date: 2014/11/04

	This is quite a 'classic' problem and the immediate thought ("just do it mySQL") doesn't work here because of the need to have the rails piece that encodes a password that is entered.
	So you need to actually use rails, something like this (this should all be happening in your local development environment which is the default when working locally):

	You need to create a user.

	Try this:

	cd the_root_of_the_project

	script/rails console

	# install ruby 2.2.3 with rbenv on ubuntu 14.04

	sudo apt-get install git-core curl zlib1g-dev build-essential libssl-dev libreadline-dev libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt1-dev libcurl4-openssl-dev python-software-properties libffi-dev

	git clone git://github.com/sstephenson/rbenv.git ~/.rbenv
	git clone git://github.com/sstephenson/ruby-build.git ~/.rbenv/plugins/ruby-build
	git clone https://github.com/sstephenson/rbenv-gem-rehash.git ~/.rbenv/plugins/rbenv-gem-rehash
	echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
	echo 'eval "$(rbenv init -)"' >> ~/.bashrc
	exec $SHELL

	/* Random.jack
	* By Mark Armbrust
	* http://nand2tetris-questions-and-answers-forum.32033.n3.nabble.com/Random-number-generator-for-hack-cpu-td4025503.html
	* Also see:
	* http://nand2tetris-questions-and-answers-forum.32033.n3.nabble.com/Pseudo-Random-Number-Generator-td4026059.html#a4027617
	*/

	class Random {
	static int seed;

	#!/bin/bash
	sudo apt-get update
	sudo apt-get upgrade
	ln -s "/mnt/c/Users/Daniel/Documents/homeflow" ~/homeflow
	ln -s "/mnt/c/Users/Daniel/Documents" ~/documents
	mkdir .ssh
	cp documents/id* .ssh/
	sudo chmod 600 .ssh/*
	cd homeflow/attis
	git pull