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