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