Create an Kubernetes cluster with Raspberry Pi 3 (Also work with 1/2) and set it up in 20 minutes using Ansible and kubeadm.
Based on Roland Huß's job and originally inspired by the post Creating a Raspberry Pi cluster running Kubernetes by Arjen Wassink and Ray Tsang.
This project automates all the configuration steps described in the Kubernetes documentation + some basic setup for all nodes.
- Create a demo cluster to show Kubernetes capabilities
- Learn more about Kubernetes installation and configuration
- Learn the basics of Ansible
Here is the hardware you will need to complete the project:
| Amount | Part | Price |
|---|---|---|
| 5 | Raspberry Pi 3 | 5 * 39 EUR |
| 5 | Micro SD Card 32 GB | 5 * 11 EUR |
| 1 | WLAN Router | 24 EUR |
| 1 | 100 MB Switch | 12 EUR |
| 5 | Micro-USB wires | 5 * 1 EUR |
| 1 | Power Supply | 43 EUR |
| 3 | Multi stackable case | 3 * 16 EUR |
| 1 | Bolt pack | 6 EUR |
Here is the software you will need to complete the project:
| Name | Origin | URL |
|---|---|---|
| HypriotOS | GitHub | hypriot/rpi-image-builder |
| flash | GitHub | hypriot/flash |
| Ansible | Website | Ansible installation guide |
Download the latest HypriotOS image from the hypriot/rpi-image-builder release page
For each SD card, flash the image (v.1.1.3 in this case).:
$ flash hypriotos-rpi-v1.1.3.img
Put the SD card in all the Pis.
RECOMMENDED: For each Pi, turn it on, find out its MAC address (e.g. using your router), set a static IP from them and reboot them to get the new IP.
Copy "hosts.example" to "hosts" and edit the file.
- Describe in "Pis" all your Raspberry Pi devices' IP (or hostname) (both master and nodes). Don't forget to set the "name" in order to rename each node during setup
- Describe in "Master" ONE of your Raspberry Pi devices that will act as cluster master
- Describe in "Nodes" the rest of Raspberry Pi devices that will act as cluster nodes (Please, do not include here the master!)
Apply the base configuration for all Pi:
$ ansible-playbook -k -i hosts setup.yml
IMPORTANT: Amongs others, the setup copies your public SSH key to all Pis and associates it to the user "Pi". Is important to check that the key exists at "~/.ssh/id_rsa.pub".
You can create a new key using the command:
ssh-keygen -t rsa -b 4096
You can set another path in /roles/base/defaults/main.yml.
Copy config.example.yml to config.yml
- Put a random Kubernetes token (<6 character string>.<16 character string>) into the "token" parameter. This token will be used for both master and nodes creation
- Put your master hostname or IP address in the "master" variable
Create the Kubernetes cluster:
$ ansible-playbook -i hosts master.yml
Join the nodes to the cluster:
$ ansible-playbook -i hosts nodes.yml
OPTIONAL: The "master.yml" file has copied for you the admin.config file from the master. This file is required to use kubectl from your computer.
- Move the file to ${HOME}/.kube/config or use the flag --kubeconfig when calling to kubectl from your computer More info
- Alternativelly, you can connect to the cluster master and execute kubectl from there.