Raspbernetes

Automated and repeatable method of deploying a headless Kubernetes stack onto a cluster of Raspberry Pis. Completely hands off experience from power on.

Detailed blog and guide posted onto my medium account:

• Headless Kubernetes on 15 Raspberry Pis boot in under 8 minutes

Prerequisites

The following tools and pre-requisites must be available on the machine being used to build the SD cards:

• Linux - Because of filesystem requirements
• bash - 4.0+
• make - 4.1+
• kubectl - 1.20.4
• 4 Raspberry Pis (3 Masters and 1 Worker)

Applications

This stack is an opinionated way to deploy a home cluster with a HA design using haproxy and keepalived for cluster management.

See below for a list of the versions and applications used:

• Raspbian - raspbian_lite-2020-02-14
• Kubernetes - 1.20.4
• Docker - 19.03.9
• HA Proxy - 1.8.19
• Keepalived - 2.0.10
• Flannel - As per instructions on kubeadm installation page

Configuration

A short explanation of each environment variable that can be overridden.

Environment Settings

Mount device configuration:

• MNT_DEVICE - Device name of SD slot on your local machine. (default: /dev/mmcblk0)

Raspberry Pi network and hostname configuration:

• RPI_NETWORK_TYPE - Network option of choice. Either eth0 or wlan0. (default: wlan0)
• RPI_HOSTNAME - Hostname for specific Raspberry Pi. (default: rpi-kube-master-01)
• RPI_IP - Static IP to set. (default: 192.168.1.101)
• RPI_GATEWAY - Generally your router ip. (default: 192.168.1.1)
• RPI_DNS - Usually the same as your router unless you run a separate DNS (default: RPI_GATEWAY)
• RPI_TIMEZONE - Local timezone. (default: Australia/Melbourne)

Kubernetes specific configuration:

• KUBE_NODE_TYPE - Type of Kubernetes node. Either master or worker. (default: master)
• KUBE_MASTER_VIP - Floating virtual IP (VIP) to use in keepalived. (default: 192.168.1.100)
• KUBE_MASTER_IP_01 - IP of 1st master node to use in haproxy. (default: 192.168.1.101)
• KUBE_MASTER_IP_02 - IP of 2nd master node to use in haproxy. (default: 192.168.1.102)
• KUBE_MASTER_IP_03 - IP of 3rd master node to use in haproxy. (default: 192.168.1.103)

Network configuration if using Wifi. Accompanied with RPI_NETWORK_TYPE of wlan0:

• WIFI_SSID - Local SSID to connect Wifi to. (default: n/a)
• WIFI_PASSWORD - Password of above SSID to connect to Wifi using wpa_supplicant. (default: n/a)

Run

Be mindful of an SSH key that gets generated with this build that is stored in the output/ssh/ directory. This is not committed to git and should be treated safe like a normal private key. If you lose this key you will no longer be able to manage your stack. This is crucial for inter-cluster communication and remoting for management.

Build

Once appropriate above environment variables have been exported to suit your specific local environment, the below command will build an SD card with all automation scripts:

make build

Help

The help target is set as the default target, so display the above brief descriptions. Use the below command as is to print to the terminal:

make