Install Kubernetes in Virtual Box

First we install ubuntu server on virtutal box

Guest additions intallation

https://cambiatealinux.com/instalar-las-guest-additions-virtualbox-ubuntu-server

sudo apt install gcc make perl

Prepare networking

NAT address to the outside world
Host only address with dhcp

Renew ip address from host only network

sudo dhclient -v enp0s8

permanent option for host only

https://fabiofernandesx.medium.com/preparing-virtual-box-vms-to-run-kubernetes-a31c7c851566

/etc/netplan

sudo -i vim /etc/netplan/01-netcfg.yaml

create the following yaml file

network: version: 2 renderer: networkd ethernets: enp0s8: dhcp4: no addresses: [192.168.56.101/24]

netplan generate sudo netplan apply

Configure access to ssh server

https://linuxize.com/post/how-to-enable-ssh-on-ubuntu-20-04/

sudo systemctl status ssh

enable firewall

sudo ufw allow ssh

ufw default allow incoming

allow connection to k8s ports

sudo ufw allow 179/tcp sudo ufw allow 4789/tcp sudo ufw allow 5473/tcp sudo ufw allow 443/tcp sudo ufw allow 6443/tcp sudo ufw allow 2379/tcp sudo ufw allow 4149/tcp sudo ufw allow 10250/tcp sudo ufw allow 10255/tcp sudo ufw allow 10256/tcp sudo ufw allow 9099/tcp

Change the hostname on the cloned VM

hostnamectl set-hostname

hostnamectl status

upgrade system

sudo apt-get update sudo apt-get upgrade -y

install vim

sudo apt-get install vim

run sudo commands without password

sudo -i

Kubernetes pre steps

Packages:

sudo apt install curl apt-transport-https vim git wget gnupg2 software-properties-common apt-transport-https ca-certificates uidmap -y

Disable swap

swapoff -a

test modules

 modprobe overlay
 modprobe br_netfilter

update kernel networking

cat << EOF | tee /etc/sysctl.d/kubernetes.conf
> net.bridge.bridge-nf-call-ip6tables = 1
> net.bridge.bridge-nf-call-iptables = 1
> net.ipv4.ip_forward = 1
> EOF

output: net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 net.ipv4.ip_forward = 1

ensure to apply changes:

sysctl --system

install software

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

apt install containerd -y

vim /etc/apt/sources.list.d/kubernetes.list add line: deb http://apt.kubernetes.io/ kubernetes-xenial main

update key

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -

 apt-get update

Kubernetes installation (here for the workernode)

apt-get install -y kubeadm=1.24.1-00 kubelet=1.24.1-00 kubectl=1.24.1-00

apt-mark hold kubeadm kubelet kubectl

kubeadm set on hold. kubelet set on hold. kubectl set on hold.

network installation CALICO

wget https://docs.projectcalico.org/manifests/calico.yaml

ip addr show

10.0.2.15

create an alias in the /etc/hosts 10.0.2.15 k8scp

kubeadm config file (kubeadm-config.yaml) apiVersion: kubeadm.k8s.io/v1beta3 kind: ClusterConfiguration kubernetesVersion: 1.24.1 controlPlaneEndpoint: “k8scp:6443” networking: podSubnet: 192.168.0.0/16

initialize the control plane

kubeadm init --config=kubeadm-config.yaml --upload-certs | tee kubeadm-ini.out

exit and run as regular user:

 mkdir -p $HOME/.kube
 sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
 sudo chown $(id -u):$(id -g) $HOME/.kube/config

network configuration

copy the calico file into the current user.

sudo cp /root/calico.yaml .

apply the config:

 kubectl apply -f calico.yaml

enable bash autocompletion

sudo apt-get install bash-completion -y

source < (kubectl completion bash) echo “source <(kubectl completion bash)” >> $HOME/.bashrc

## view config sudo kubeadm config print init-defaults

apiVersion: kubeadm.k8s.io/v1beta3 bootstrapTokens: - groups: - system:bootstrappers:kubeadm:default-node-token token: abcdef.0123456789abcdef ttl: 24h0m0s usages: - signing - authentication kind: InitConfiguration localAPIEndpoint: advertiseAddress: 1.2.3.4 bindPort: 6443 nodeRegistration: criSocket: unix:///var/run/containerd/containerd.sock imagePullPolicy: IfNotPresent name: node taints: null

apiServer: timeoutForControlPlane: 4m0s apiVersion: kubeadm.k8s.io/v1beta3 certificatesDir: /etc/kubernetes/pki clusterName: kubernetes

Configure worker node

network config

cat /etc/netplan/01-netcfg.yaml network: version: 2 renderer: networkd ethernets: enp0s8: dhcp4: no addresses: [192.168.56.103/24]

netplan generate netplan apply

update hostname file with ens4 ip ip addr show enp0s3 | grep inet inet 10.0.2.15/24 metric 100 brd 10.0.2.255 scope global dynamic enp0s3 inet6 fe80::a00:27ff:fe31:54bd/64 scope link

on the control plane

get the token politeles@cp:~$ sudo kubeadm token create qsm8ss.g8vf8w8qbro4z1vo politeles@cp:~$ openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed ‘s/^.* //’ dce22f3d49e94e10e282e64024b9b5fddaa6ed78a635a8a744e4c55446e3a328

on the worker node

update /etc/hosts with the hostname of the control plane

root@worker1:~# cat /etc/hosts
10.0.2.15 k8scp

Join the cluster

untaint the control plane (just for non-prod)

kubectl taint nodes --all node-role.kubernetes.io/control-plane-

node/cp untainted error: taint “node-role.kubernetes.io/control-plane” not found

update containerd config

 sudo crictl config --set runtime-endpoint=unix:///run/containerd/containterd.sock --set image-endpoint=unix:///run/containerd/containerd.sock