K8s on Raspbian

k8s-pi.md

This guide has moved to a GitHub repository to enable collaboration and community input via pull-requests.

https://github.com/alexellis/k8s-on-raspbian

Alex

prep.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 cgroup_enable=memory" 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 cgroup_enable=memory"
echo $orig | sudo tee /boot/cmdline.txt

echo Please reboot

quick.md

Use this to setup quickly

# curl -sL \
 https://gist.githubusercontent.com/alexellis/fdbc90de7691a1b9edb545c17da2d975/raw/b04f1e9250c61a8ff554bfe3475b6dd050062484/prep.sh \
 | sudo sh

Oooookayy... I finally managed to get it working \o/

I wrote a small bash script that checks for /etc/kubernetes/manifests/kube-apiserver.yaml to update failureThreshold (new value: 100) and initialDelaySeconds (new value: 1080) as soon as the file exists. The new values are much bigger than they need to be, but they allowed my to get my master node up and running! Whenever I tried to change these values this by hand, the kubeadm init ... command failed.

I just set up a working cluster but couldn't get the master running on an RPI 2. Moved SD card over to a RPI 3 and then kubeadm init ran just fine. The worker node seem to run just fine on the RPI 2.

Wondering if anyone has gotten helm/tiller working in this configuration?

@rnbwkat I got it working but I had to specify a different tiller image, one which was compatible with ARM. The command I used was:

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

@janpieper. I’ve run into the “node not found”. looking through all the comments I was going to follow the save steps you did. I wonder what versions of k8s and docker you’ve installed

I tried to setup the cluster following the steps described but still didn't get a succesful kubeadm init. I tried different versions of k8s and docker. Is there somebody who has the steps to get 1.13-3 working with 18.09.0

@janpieper can you share the script?

@janpieper steps worked up until the point everyone mentioned, and rather than the script that polls and zaps the config, I found you can do the same (after the initial failure) by running these commands (lifted from this issue kubernetes/kubeadm#1380)

sudo kubeadm reset
sudo kubeadm init phase certs all
sudo kubeadm init phase kubeconfig all
sudo kubeadm init phase control-plane all --pod-network-cidr 10.244.0.0/16
sudo sed -i 's/initialDelaySeconds: [0-9][0-9]/initialDelaySeconds: 240/g' /etc/kubernetes/manifests/kube-apiserver.yaml
sudo sed -i 's/failureThreshold: [0-9]/failureThreshold: 18/g'             /etc/kubernetes/manifests/kube-apiserver.yaml
sudo sed -i 's/timeoutSeconds: [0-9][0-9]/timeoutSeconds: 20/g'            /etc/kubernetes/manifests/kube-apiserver.yaml
sudo kubeadm init --v=1 --skip-phases=certs,kubeconfig,control-plane --ignore-preflight-errors=all --pod-network-cidr 10.244.0.0/16

Then I installed flannel.

kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.11.0/Documentation/kube-flannel.yml

Something that threw me off was the shell demo that Kubernetes provides works fine (kubectl apply -f https://k8s.io/examples/application/shell-demo.yaml) docs here:
https://kubernetes.io/docs/tasks/debug-application-cluster/get-shell-running-container/

But it fails when doing a deployment of nginx from their example here:
https://kubernetes.io/docs/tasks/run-application/run-stateless-application-deployment/

Turns out the nginx image isn't compatible with ARM, once I changed the image to a pi supported image (tobi312/rpi-nginx
) it worked fine! Thanks to everyone here, I finally got my pi cluster going.