====== Raspberry Pi Computing Cluster ======

===== Some Background =====

There are a number of approaches to parallel cluster processing.

  * [[https://kubernetes.io/|Kubernetes]]
  * [[https://docs.docker.com/engine/swarm/|Docker Swarm]]
  * [[https://www.openstack.org/|OpenStack]]
  * [[https://mesos.apache.org/|Apache Mesos]]
  * [[https://hadoop.apache.org/docs/current/hadoop-yarn/hadoop-yarn-site/YARN.html|Apache Hadoop YARN]]
  * [[https://www.nomadproject.io/|Nomad]]

===== Setup =====

On a fresh RPi here are the steps

  * Install Python 3, remove Python 2
  * Install Docker
  * Install Kubernetes
  * [[https://coreos.com/flannel/docs/latest/|Flannel]] - Virtual network that attaches IP addresses to containers
  * [[https://kind.sigs.k8s.io/|Kind]] - A tool for running local Kubernetes clusters using Docker container “nodes”

==== Docker ====

[[https://blog.alexellis.io/getting-started-with-docker-on-raspberry-pi/|Get Started with Docker on Raspberry Pi]]

An automated script maintained by the Docker project will create a systemd service file and copy the relevant Docker binaries into /usr/bin/.

  sudo curl -sSL https://get.docker.com | sh

Set Docker to auto-start:

  sudo systemctl enable docker

Or start Docker manually:

  sudo systemctl start docker

The Docker client can only be used by root or members of the docker group. Add pi or your equivalent user to the docker group:

  sudo usermod -aG docker pi

Test the Docker install by downloading and running Alpine Linux:

  docker run -ti arm32v6/alpine:3.5 /bin/sh

Note that Docker creates a new docker0 network interface.

==== Kubernetes ====

[[https://blog.hypriot.com/post/setup-kubernetes-raspberry-pi-cluster/|Setup Kubernetes on a Raspberry Pi Cluster]]

First, trust the kubernetes APT key and add the official APT Kubernetes repository on every node:

  curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg > apt-key.gpg
  sudo apt-key add apt-key.gpg
  echo "deb http://apt.kubernetes.io/ kubernetes-xenial main" > /etc/apt/sources.list.d/kubernetes.list

Install kubeadm on every node:

  apt-get update
  apt-get install -y kubeadm