Yet another “Kubernetes with Raspberry Pi” post

By Tomica Kaniski in Other 4 Comments

There’s a ton of the tutorials on how to get Kubernetes installed onto your Raspberry Pi, so… let’s write another one. 😊

As mentioned in my last post, I’ve found my forgotten Raspberry Pi, and played around with installing and configuring Raspbian Buster on it.

Today, I wanted to check if it will be possible to install Kubernetes onto such small machine – they are many articles on the “widest of the world’s webs” that say “Yes, it can be done!“, so I’ve decided to give it a try! And I chose to follow one of them (seemed like a nice reference).

As you remember, I’m starting with a cleanly installed (and just slightly customized) Raspbian Buster and building it from there.

And I’ll be using kubeadm for installing my cluster.

So, once I had at least two machines (my Raspberry Pi for the “control plane” and Ubuntu 20.04 LTS Hyper-V virtual machine as the “node” – you can read more about it here), I prepared them like this:

  • install Docker (in my case)
  • change the default cgroups driver for Docker to systemd
  • add cgroups limit support (for my Raspberry Pi 3)
  • configure iptables
  • disable swap (this one was a bit challenging)
  • prepare for Kubernetes installation (source, keys, kubeadm)
  • install Kubernetes “control plane”
  • add flannel
  • add a node to the cluster
  • test with some workload

One thing that bothered me (on Buster) was disabling swap in a way that it also stays disabled after a reboot (I know, it’s the details that eventually get you) – after a while, I’ve stumbled on this forum post and the solution provided by “powerpete” did the trick! Thank you, @powerpete! 😊

And finally, details about the each step are here (outputs are commented and somewhat redacted/condensed):

Seems to be working (😊):

Cheers!

P.S. I’ve read about some having issues with flannel and using other network options (didn’t have this one). Also, if you’ll have issues with iptables (v1.8+), maybe you’ll need to switch to legacy version (didn’t have this one either).

Found my forgotten Raspberry Pi

By Tomica Kaniski in Other 2 Comments

And, naturally, decided to put it to use (although, for exactly what… is currently unclear). 😊

So… how?

As there was already a micro SD card inside my Raspberry Pi, I was all set!

Basically, what I had to do:

  • download the OS image (Raspberry Pi OS Lite)
  • download imaging software (Etcher)
  • extract the OS onto micro SD card
  • enable SSH by adding an empty file called “ssh” (yes, without any extension) to the boot volume
  • boot it up
  • set it up as I like

Extracting the OS image onto micro SD card is a “breeze” with right tools – select OS image, select where do you want to put it and click Flash:

After it’s finished, don’t forget to enable yourself the SSH access (it’s easier that way):

Done.

Let’s put the card back into Raspberry Pi and boot it up.

Few seconds later, you can use (e.g.) Windows Terminal and included SSH client to access your Raspberry Pi (default networking option is DHCP, with default username of pi and password raspberry):

I wanted to “tweak” my installation a bit (with the provided raspi-config script), so I’ve used the following for disabling unnecessary devices, custom network settings, etc.:

# raspi-config script is located in /usr/bin/raspi-config
# settings (some of them) are located in /boot/config.txt

# update the raspi-config script (or you can use 'sudo raspi-config nonint do_update') and vim... is nice to have
sudo apt update
sudo apt install -y raspi-config vim

# set static ip address (configure in '/etc/dhcpcd.conf', can check interfaces with 'ip link' - can be done nicer, but... :))
echo 'interface eth0' | sudo tee -a /etc/dhcpcd.conf
echo 'static ip_address=192.168.12.101/24' | sudo tee -a /etc/dhcpcd.conf
echo 'static routers=192.168.12.1' | sudo tee -a /etc/dhcpcd.conf
echo 'static domain_name_servers=192.168.12.1' | sudo tee -a /etc/dhcpcd.conf

# set password (for user 'pi')
echo "pi:MyExtraSecretPass#123" | sudo chpasswd

# set boot options to my liking
sudo raspi-config nonint do_boot_behaviour B1
sudo raspi-config nonint do_boot_wait 1

# set/disable unnecessary interfaces
sudo raspi-config nonint do_camera 1
sudo raspi-config nonint do_ssh 0
sudo raspi-config nonint do_vnc 1
sudo raspi-config nonint do_spi 1
sudo raspi-config nonint do_i2c 1
sudo raspi-config nonint do_serial 1
sudo raspi-config nonint do_onewire 1
sudo raspi-config nonint do_rgpio 1
sudo raspi-config nonint do_memory_split 16
sudo raspi-config nonint do_expand_rootfs
sudo raspi-config nonint do_wifi_country HR
sudo raspi-config nonint do_change_timezone Europe/Zagreb

# upgrade packages and set hostname
sudo apt upgrade -y
sudo raspi-config nonint do_hostname pimaster
sudo reboot

# ssh back into your pimaster
ssh [email protected]

And after a while, my Raspberry Pi is finally ready:

Cheers!