Ivan Larin Pentusha

Deploy K3s and Rancher on Raspberry Pi 4 cluster

Today I tried to setup a small Kubernetes cluster on top of 3 Raspberry Pi 4 (4GB Memory). Here is the steps to install the cluster.

Preparation

I have 3 Raspberry Pi 4 stacked with PoE headers and connected to a PoE switch at home. The are connected to Internet through a home router. All Pis are equipped with a 64GB Samsung SDXC card flushed with Ubuntu 20.04 image.

You'll need

Raspberry Pi 3, 3+ or 2 (only)
A Linux PC, laptop or Raspberry with SD card reader/slot
A number of Raspberry Pis configured with Ethernet

You must have an SSH key, if you don't know what this is then type in ssh-keygen and follow the instructions.

Prepare to provision RPis:

About

This gist will show how to setup Raspbian Stretch as a headless Bluetooth A2DP audio sink. This will allow your phone, laptop or other Bluetooth device to play audio wirelessly through a Rasperry Pi.

Motivation

A quick search will turn up a plethora of tutorials on setting up A2DP on the Raspberry Pi. However, I felt this gist was necessary because this solution is:

Automatic & Headless - Once setup, the system is entirely automatic. No user iteration is required to pair, connect or start playback. Therefore the Raspberry Pi can be run headless.
Simple - This solution has few dependencies, readily available packages and minimal configuration.
Up to date - As of December 2017. Written for Raspbian Stretch & Bluez 5.43

Prerequisites

Getting access token

Enable developer console in browser and navigate to:

https://www.facebook.com/v2.6/dialog/oauth?redirect_uri=fb464891386855067%3A%2F%2Fauthorize%2F&scope=user_birthday%2Cuser_photos%2Cuser_education_history%2Cemail%2Cuser_relationship_details%2Cuser_friends%2Cuser_work_history%2Cuser_likes&response_type=token%2Csigned_request&client_id=464891386855067&ret=login&fallback_redirect_uri=221e1158-f2e9-1452-1a05-8983f99f7d6e&ext=1556057433&hash=Aea6jWwMP_tDMQ9y

Look for the response of POST request in the network tab of developer console: https://www.facebook.com/v2.6/dialog/oauth/confirm?dpr=1 it contains the access token parameter. Just search for 'access_token' in the response. For the lazy people (like myself) i made a small helper that parses the token from response https://taseppa.github.io/tokenparser.github.io/

	apiVersion: batch/v1beta1
	kind: CronJob
	metadata:
	name: postgres-backup
	spec:
	schedule: "0 12 * * *"
	jobTemplate:
	spec:
	backoffLimit: 0
	template:

	# Do the first 6 steps only once.
	1. pip install --user alembic
	2. bash: ``cd {{my_project}} && alembic init alembic``
	3. bash: ``text_editor {{my_project}}/alembic.ini``
	4. Change: "sqlalchemy.url = postgres://{{username}}:{{password}}@{{address}}/{{db_name}}"
	5. bash: ``text_editor {{my_project}}/alembic/env.py``
	6. Now, import your metadata/db object from your app.:

	# {{my_project}}/{{my_project_dir}}/app.py

	from rest_framework import viewsets
	from rest_framework.response import Response

	# https://gist.github.com/ivlevdenis/a0c8f5b472b6b8550bbb016c6a30e0be


	class ExtendViewSet(object):
	"""
	This viewset mixin class with extended options list.
	"""

	import crypto from "k6/crypto";
	import encoding from "k6/encoding";

	const algToHash = {
	HS256: "sha256",
	HS384: "sha384",
	HS512: "sha512"
	};

	function sign(data, hashAlg, secret) {

	# Finding roots of polynomials in p-adic integers using Hensel's lemma

	from padic import *
	from poly import *

	def roots(p, poly):
	'Yield all roots of polynomial in the given p-adic integers.'
	for root in xrange(p):
	try:
	yield PAdicPoly(p, poly, root)

	#!/bin/bash
	apt-get install -y curl unzip

	mkdir -p /var/lib/consul
	mkdir -p /usr/share/consul
	mkdir -p /etc/consul/conf.d

	curl -OL https://releases.hashicorp.com/consul/0.7.5/consul_0.7.5_linux_amd64.zip
	unzip consul_0.7.5_linux_amd64.zip
	mv consul /usr/local/bin/consul