Setting up Kubernetes on Raspberry Pi

raspberry_pi_set_up_kubernetes

# ------------------------------------------------------------------
# INSTALLING KUBERNETES on a physical node (regular or raspberry pi)
# ------------------------------------------------------------------
#
# Chris Wraith @jacksonps4
#
# Raspbian: From 2019-09-26-raspbian-buster-lite
# Kubernetes: v1.16.1 - v1.23.4
#
# Run this script as root
# 


#
# prepare apt
#
apt-get update


#
# install Docker
#
apt-get install docker.io


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


#
# install Kubernetes
#
apt-get install -y kubeadm


#
# (Raspberry Pi only) Add the following to the end of /boot/cmdline.txt
#
# cgroup_enable=cpuset cgroup_memory=1


#
# configure networking
#   NB: add this to /etc/sysctl.conf to apply it permanently
#
sysctl net.bridge.bridge-nf-call-iptables=1


#
# turn off the swapfile permanently
#
# this turns off swap until reboot
swapoff -a        

# (Raspberry Pi only) this turns it off permanently
dphys-swapfile swapoff
dphys-swapfile uninstall
update-rc.d dphys-swapfile remove
apt purge dphys-swapfile

# (Other node types)
# delete the swap entry from /etc/fstab


# 
# create a cluster
# 
# Notes
#  - you can change the network CIDR address but you need to do the same in your network plugin (Flannel, Calico, etc)
#  - you can optionally set the DNS suffix and kubernetes API SANs
#
kubeadm init --pod-network-cidr 10.244.0.0/16 [--service-dns-domain <dns suffix>] [--apiserver-cert-extra-sans <san1>,<san2>,...]


#
# download and apply the network plugin (Flannel in this case)
#
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/a70459be0084506e4ec919aa1c114638878db11b/Documentation/kube-flannel.yml



# If you're using Calico and this isn't your first node in the cluster, check and see if all is working. If you see errors like this:
# 
#
# This is the solution:
# mkdir -p /etc/cni/net.d
#
# Find the calico config from elsewhere in your cluster
# ON ANOTHER NODE: get the file contents
# $ cat /etc/cni/net.d/10-calico.conflist
# COPY THE CONTENTS to /etc/cni/net.d/10-calico.conflist on the new node
# Tweak the arch if needed
# $ curl -LO https://github.com/projectcalico/cni-plugin/releases/download/v3.17.1/calico-arm64
# $ mv calico-arm64 /opt/cni/bin/calico
# $ ln -s /run/dnsmasq /run/systemd/resolve



#
# To add worker nodes
# 
# (on a control plane node)
kubeadm token create --print-join-command       # step 1

# (on the new worker target node)
<command-from-above-step-1>

#
# To add another control plane node (assumes you already have an HAProxy setup to load balance across the nodes)
# 
# (on a control plane node)
kubeadm init phase upload-certs --upload-certs  # step 1
kubeadm token create --print-join-command       # step 2

# (on the new control plane target node)
kubeadm join <control-plane-address>:<control-plane-port> --token <token-from-above-step-2> --control-plane --certificate-key <token-from-above-step-1> --discovery-token-ca-cert-hash <token-from-above-step-1>