K3S Deployment

Setting up the Raspberry Pi’s

This guide is great for the setup up the Raspberry Pi’s and also include the K3S and MetalLB deployment described here.

Once the OS is installed and the Nodes are accessible using SSH we can begin the deployment process

As part of the OS installation with the Raspberry Pi Imager I already set my Hostnames as required

I also Used my DHCP server to assign fixed IP’s to each Pi

SHomeK3SM01 – 10.30.0.10 – Master Node

SHomeK3SW01 – 10.30.0.11 – Worker Node 1

SHomeK3SW01 – 10.30.0.12 – Worker Node 2

SHomeK3SW01 – 10.30.0.13 – Worker Node 3

You can use hostname and ip a to confirm this

ubuntu@SHomeK3SM01:~$ hostname
SHomeK3SM01
ubuntu@SHomeK3SM01:~$ ip a show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether e4:5f:01:0a:5e:1c brd ff:ff:ff:ff:ff:ff
    inet 10.30.0.10/24 brd 10.30.0.255 scope global dynamic eth0
       valid_lft 82137sec preferred_lft 82137sec
    inet6 fe80::e65f:1ff:fe0a:5e1c/64 scope link
       valid_lft forever preferred_lft forever

Preparing OS

Our First task is to get the OS ready to run Containers.

The below needs to be run on all Nodes. As per the Guide mentioned this can be done using Ansible but I Used mtputty to just run it on al 4 nodes at once

sudo sed -i '$ s/$/ cgroup_enable=cpuset cgroup_enable=memory cgroup_memory=1 swapaccount=1/' /boot/firmware/cmdline.txt

Fixing IP Tables can be done by creating a k3s.conf file with the config

echo "net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1" > ~/k3s.conf

now this needs to be moved to the correct path and the correct permissions and owner set

sudo mv k3s.conf /etc/sysctl.d/k3s.conf
sudo chown root:root /etc/sysctl.d/k3s.conf
sudo chmod 0644 /etc/sysctl.d/k3s.conf

If you also dislike IPv6 then append the below to your /etc/sysctl.d/99-sysctl.conf file

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.eth0.disable_ipv6 = 1

Time for a Reboot before we continue.

Installing K3S

Time to start the K3S setup, This is done easily with a Install script and some parameters.

I will start with the single master node.

sudo curl -sfL https://get.k3s.io | K3S_TOKEN="Your Super Awesome Password" sh -s - --cluster-init --disable servicelb

The –cluster-init is to initialize the first node. We also use –disable servicelb as we will be using MetalLB for load balancing.

Give it about a minute to settle. you can check that the node is up using sudo kubectl get nodes

Next up the Worker Nodes. The K3S_URL should be set to the IP of the Master Node you deployed earlier, the FQDN can also be used.

sudo curl -sfL https://get.k3s.io | K3S_URL="https://10.30.0.10:6443" K3S_TOKEN="Your Super Awesome Password" sh -

Now I like to do a watch and just check that all the nodes are up

Great Now we have a nearly Functioning Kubernetes Cluster(still needs a Load Balancer).

To make it look a bit prettier I like to label my Worker Nodes

Labelling Workers

In the next Post we will deploy MetalLB and the Monitoring.

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