This Ansible playbook turns your fleet of Raspberry Pi into Kubernetes cattle with k3s, the streamlined version of Kubernetes by @rancher that runs silky smooth on the ARM processor powering your Pi.

Manually prepare your Raspberries

Burn Raspian Stretch Lite on an SD card with EtcherBalena, or something alike
Create an empty ssh file in the root of the SD card (volume is called boot)

Secure your Raspberries

Optional but advisable: use SSH key auth and disable password login. The default ssh credentials for a Raspberry Pi are username pi and password raspberry.

Copy your pubkey to the Pi with ssh-copy-id pi@kube1.example.com

Configure ansible setup

Copy ansible/hosts.template to ansible/hosts for your configuration
Choose one of the Raspberries to lead / orchestrate your cluster; we'll call this the server
In ansible/hosts, fill out the ip or hostname for the leading Raspberry under [k3s-server]
Fill out the ip's or hostnames for the rest of your cattle under [k3s-agents]
change the password in the group_vars
pick a version of k3s to install

Provision the nodes

When you're all set up and configured, run the Ansible playbook:

Ansible in a conatiner

Build a player

docker build -t lcwyo/ansible-player .

Run the player

docker run --rm -it \
    -v ~/.ssh/id_rsa:/root/.ssh/id_rsa \
    -v ~/.ssh/id_rsa.pub:/root/.ssh/id_rsa.pub \
    -v $(pwd):/ansible/ \
    lcwyo/ansible-player /ansible/site.yml -i /ansible/hosts

This will:

Configure and prepare the Raspberries for k3s
Install the k3s binary on the 'server' Pi (the leading node)
Install a k3s-server service on the server and start it
Fetch the node token from the server
Install and start a k3s-agent service on the agents, joining the cluster
Enable autostart on boot for k3s on all nodes

See if it worked

Log into your server node and run:

$ sudo k3s kubectl get nodes -o wide

You should see all of your nodes broadcasting a Ready status.

Happy cattle herding!

#todo#

need to find some storage class...

Install Helm

Download helm

curl https://raw.githubusercontent.com/kubernetes/helm/master/scripts/get > install-helm.sh

Make instalation script executable

chmod u+x install-helm.sh

Install helm ./install-helm.sh

Prepare & Install tiller

kubectl -n kube-system create serviceaccount tiller

kubectl create clusterrolebinding tiller --clusterrole cluster-admin --serviceaccount=kube-system:tiller

tiller needs an arm image, so we use the arm image from jessestuart

helm init --tiller-image=jessestuart/tiller:v2.9.0 --service-account tiller --upgrade

use arm helm charts

helm repo add arm-stable https://peterhuene.github.io/arm-charts/stable

lcwyo/ansible-k3s-rpi