Ubuntu kubernetes installation

System preparation

$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=24.04
DISTRIB_CODENAME=noble
DISTRIB_DESCRIPTION="Ubuntu 24.04.2 LTS"

(Optional) Remove previous kubernetes installation

sudo apt purge kubeadm kubelet kubectl kubernetes-cni
sudo apt autoremove
sudo rm /etc/apt/sources.list.d/kubernetes.list*

Updrage

sudo apt update
sudo apt upgrade
do-release-upgrade

(Optional) Mount data disk

mkfs.xfs /dev/vdb
lsof /var
mv /var/ /var0
mkdir /mnt/newvar/
mount /dev/vdb /mnt/newvar/
rsync -aqxP /var0/* /mnt/newvar/
umount /mnt/newvar
mkdir /var
mount /dev/vdb /var

vim /etc/fstab
# /dev/vdb /var xfs  defaults 0 0

System configuration

Enable ipv4 forward:

# sysctl params required by setup, params persist across reboots
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward = 1
EOF

# Apply sysctl params without reboot
sudo sysctl --system

Verify:

$ sysctl net.ipv4.ip_forward
net.ipv4.ip_forward = 1

Disable swap

# check if swap is disabled
swapon -s

Install Kubernetes

Containerd runtime

• Install docker on ubuntu:
• Tsinghua docker mirror help:

# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc

# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

# Use mirror instead:
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg
sudo chmod a+r /etc/apt/keyrings/docker.asc
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://mirrors.tuna.tsinghua.edu.cn/docker-ce/linux/ubuntu \
  "$(. /etc/os-release && echo "$VERSION_CODENAME")" stable" | \
  tee /etc/apt/sources.list.d/docker.list > /dev/null

sudo apt-get update

sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

sudo usermod -aG docker $USER
sudo systemctl enable docker.service
sudo systemctl enable containerd.service

Generate containerd config using systemd:

sudo containerd config default | sudo tee /etc/containerd/config.toml

And modify it:

[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
  ...
  [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
    SystemdCgroup = true

sandbox_image = "registry.aliyuncs.com/google_containers/pause:3.6"

Restart the service:

sudo systemctl restart containerd

The above steps is required, otherwise might get error:

validate CRI v1 runtime API for endpoint "unix:///var/run/containerd/containerd.sock": rpc error: code = Unimplemented desc = unknown service runtime.v1.RuntimeService[preflight

Install Kubeadm

Install kubeadm:

sudo apt-get install -y apt-transport-https ca-certificates curl gpg
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.32/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg

echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.32/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list

sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl

Create cluster on Master node

Create cluster via kubeadm:

sudo systemctl start kubelet
sudo systemctl enable kubelet

MASTER_IP="83.229.126.124"
NODENAME=$(hostname -s)
POD_CIDR="192.168.0.0/16"

sudo kubeadm init \
  --pod-network-cidr=$POD_CIDR \
  --apiserver-advertise-address=$MASTER_IP \
  --control-plane-endpoint=$MASTER_IP \
  --node-name $NODENAME

(Optional) It takes long time to pull images, so we can pull images first:

kubeadm config images list
kubeadm config images pull

to view images in local host:

ctr -n k8s.io images list

Generate config

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

# root
export KUBECONFIG=/etc/kubernetes/admin.conf

Now you should be able to view the cluster nodes:

$ kubectl get nodes
NAME    STATUS   ROLES           AGE    VERSION
riguz   Ready    control-plane   2m8s   v1.32.3

Post installation =

Install CNI plugin

Calico quick start:

kubectl create -f https://raw.githubusercontent.com/projectcalico/calico/v3.29.3/manifests/tigera-operator.yaml
kubectl create -f https://raw.githubusercontent.com/projectcalico/calico/v3.29.3/manifests/custom-resources.yaml

watch kubectl get pods -n calico-system

NAME                                      READY   STATUS    RESTARTS   AGE
calico-kube-controllers-7bc6b5bb8-5dnsf   1/1     Running   0          26m
calico-node-jdw2v                         1/1     Running   0          26m
calico-typha-5c754949c6-qhfwz             1/1     Running   0          26m
csi-node-driver-9wmmd                     2/2     Running   0          26m

By default, your cluster will not schedule Pods on the control plane nodes for security reasons. If you want to be able to schedule Pods on the control plane nodes:

kubectl taint nodes --all node-role.kubernetes.io/master-

$ kubectl get nodes -o wide
NAME    STATUS   ROLES           AGE   VERSION   INTERNAL-IP      EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION     CONTAINER-RUNTIME
riguz   Ready    control-plane   13m   v1.32.3   83.229.126.124   <none>        Ubuntu 24.04.2 LTS   6.8.0-58-generic   containerd://1.7.27

(Optional) Join nodes

kubeadm join 10.19.30.61:6443 --token xxx \
    --node-name node02 \
	--discovery-token-ca-cert-hash xxx

Install HELM

wget https://get.helm.sh/helm-v3.14.4-linux-amd64.tar.gz
tar -zxvf helm-v3.14.4-linux-amd64.tar.gz
install linux-amd64/helm /usr/local/bin/helm