RaspberryPi Kubernetes Cluster

Here I'm sharing details on how to start your own in-house Kubernetes cluster using multiple Raspberry Pi computers. This can be beneficial for the development of your own projects and gives you a fun tool to play around with.

I've built my cluster with these methods and now using it as my personal server for hosting and practicing cloud development.

Information

Term	Details
OS	RASPBIAN STRETCH LITE
Cluster	multiple computers that are able to communicate with each otehr to accomplish given task
Slave Node	a single computer running inside your cluster (in this case a single Raspberry Pi)
Master Node	pretty much the same as a typical node but is responsible for gluing all of your cluster together and managing it's state

Photos - https://photos.app.goo.gl/xIVB6uBk3uCoifJX2

Tutorial

Step I - Prepare each Raspberry Pi

Installation of a cluster should be done on a fresh system to avoid any conflicts.

1. Download Raspbian Lite Operating System
   • https://downloads.raspberrypi.org/raspbian_lite/images/raspbian_lite-2017-12-01/
   • Pick zip file, no need to unzip it
2. Download balenaEtcher
   • https://www.balena.io/etcher/
3. For each of your Raspberry Pi (this will erase all your data on the card!)
   1. Insert it's microSD card to your computer
   2. Burn the card with Raspian system using balenaEtcher
   3. After burning OS image on card, enter card directory and add ssh file
      • touch ssh
      • this will allow us to connect to our nodes by ssh
   4. After adding this file, place card in your Raspberry Pi node and start it
4. After you prepare all of your nodes, continue to the next step

Step II - Prepare your system to setup Cluster

1. Open your shell
   • If you are running Windows 10
     1. Open PowerShell as Administrator
     2. Run this command
        • Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux
     3. Reboot
     4. Install Ubuntu on Windows
     5. Reboot
     6. If you want to browse your files with Windows Explorer then it's probably located at
        • C:\Users\USER_NAME\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs
2. Move to some directory dedicated to this project
   • cd ~
3. Clone this repository
   • git clone https://github.com/patrykkrawczyk/RPiClusterCloud
4. Change into repository directory
   • cd RPiClusterCloud

Step III - Configure ip_addresses.txt file

Here we'll define IP addresses that our router automatically assigned to our nodes

1. Find out your router IP address, usually it's 192.168.0.1
2. Log in to your router administration panel, usually you can find credentials on the sticker on the back of your router
3. Find out IP addresses of your Raspberry Pi nodes in your network
4. Edit ip_addresses.txt file in RPiClusterCloud directory
   • nano resources/ip_addresses.txt
5. Write all of the node IP addresses in separate lines
   • Make sure to specify your Master Node IP address in the first line
   • Make sure that these addresses don't collide with addresses specified in node_addresses.txt

Step IV - Configure node_addresses file

Here we'll define static IP addresses that should be assigned to each node after Cluster setup is complete

1. Edit node_addresses.txt file in RPiClusterCloud directory
   • nano resources/node_addresses.txt
2. Write all of the desired static node IP addresses in separate lines
   • Make sure to specify your Master Node desired static IP address in the first line
   • Make sure that these addresses don't collide with addresses specified in ip_addresses.txt

Step V - Configure node_hostnames file

Here we'll define hostnames that should be assigned to each node after Cluster setup is complete

1. Edit node_hostnames.txt file in RPiClusterCloud directory
   • nano resources/node_hostnames.txt
2. Write all of the desired node hostnames in separate lines
   • Make sure to specify your Master Node desired hostname in the first line

Step VI - Checkpoint

Make sure everything is configured properly

1. ip_addresses, node_addresses.txt, node_hostnames.txt has the same number of lines

2. All rows within these files refer to the same node

   ip_addresses	node_addresses	node_hostnames
   192.168.0.204	192.168.0.101	rpinode01
   192.168.0.205	192.168.0.102	rpinode02
   192.168.0.202	192.168.0.103	rpinode03

   Such configuration would result in 3 node cluster where

   • rpinode01 is a Master Node with static IP 192.168.0.101
   • rpinode02 is a Slave Node with static IP 192.168.0.102
   • rpinode03 is a Slave Node with static IP 192.168.0.103

Step VII - Run Cluster setup script

1. Script assumes default Raspberry Pi credentials which are
   • pi / raspberry
2. Execute setup_cluster.sh script with router_id as argument and sudo rights
   • sudo ./scripts/setup_cluster.sh 192.168.0.1
3. If anything goes wrong you can look at /var/log/setup_*.log files on each node file system