Installs Docker and Kubernetes on a Raspberry Pi running Stretch

kube-install.sh

#!/bin/sh

# This installs the base instructions up to the point of joining / creating a cluster

curl -sSL get.docker.com | sh && sudo usermod pi -aG docker

sudo dphys-swapfile swapoff && \
  sudo dphys-swapfile uninstall && \
  sudo update-rc.d dphys-swapfile remove

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add - && \
  echo "deb http://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list && \
  sudo apt-get update -q && \
  sudo apt-get install -qy kubeadm
    
echo Adding " cgroup_enable=cpuset cgroup_memory=1" to /boot/cmdline.txt

sudo cp /boot/cmdline.txt /boot/cmdline_backup.txt
orig="$(head -n1 /boot/cmdline.txt) cgroup_enable=cpuset cgroup_memory=1"
echo $orig | sudo tee /boot/cmdline.txt

echo Please reboot

markdownrender.yaml

apiVersion: v1
kind: Service
metadata:
  name: markdownrender
  labels:
    app: markdownrender
spec:
  type: NodePort
  ports:
    - port: 8080
      protocol: TCP
      targetPort: 8080
      nodePort: 31118
  selector:
    app: markdownrender
---
apiVersion: apps/v1beta1 # for versions before 1.6.0 use extensions/v1beta1
kind: Deployment
metadata:
  name: markdownrender
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: markdownrender
    spec:
      containers:
      - name: markdownrender
        image: functions/markdownrender:latest-armhf
        imagePullPolicy: Always
        ports:
        - containerPort: 8080
          protocol: TCP

update-node.sh

#!/bin/bash
  
HOST=$1

if [ "$1" = "" ]; then
  echo "Need host name of node."
else
  echo "Placing $HOST into maintenance mode."
  kubectl drain $HOST --ignore-daemonsets
  echo "Upgrading node."
  ssh pi@$HOST.local 'sudo apt-get -q update && sudo apt-get -y upgrade && systemctl status kubelet | grep Active:'
  echo "Bringing $HOST back online"
  kubectl uncordon $HOST
  echo "Rebooting $HOST."
  ssh pi@$HOST.local 'sudo reboot'
  echo "Upgrade of $HOST complete."
fi