Install kubernetes with kubeadm

Kubernetes
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Kubeadm is a tool that helps you bootstrap a simple Kubernetes cluster and simplifies the deployment process.

Parts of the Kubernetes series

192.168.1.41  kubernetes01 # master node
192.168.1.42  kubernetes02 # frontend node
192.168.1.43  kubernetes03 # worker node
192.168.1.44  kubernetes04 # worker node
192.168.1.45  kubernetes05 # worker node

# hardware requirement
4 CPU
16G RAM

Install Docker

apt-get update
apt-get install apt-transport-https ca-certificates curl gnupg2 software-properties-common
curl -fsSL https://download.docker.com/linux/debian/gpg | sudo apt-key add -
add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/debian $(lsb_release -cs) stable"

apt-get update
apt-get install containerd.io

## Configure containerd
sudo mkdir -p /etc/containerd
sudo containerd config default > /etc/containerd/config.toml

To use the systemd cgroup driver in /etc/containerd/config.toml with runc, set

nano /etc/containerd/config.toml
...
          [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
            SystemdCgroup = true

Configuuration

cat <<EOF | sudo tee /etc/modules-load.d/containerd.conf
overlay
br_netfilter
kvm-intel
EOF

sudo modprobe overlay
sudo modprobe br_netfilter

cat <<EOF | sudo tee /etc/sysctl.d/99-kubernetes-cri.conf
net.bridge.bridge-nf-call-iptables  = 1
net.ipv4.ip_forward                 = 1
net.bridge.bridge-nf-call-ip6tables = 1
EOF

sysctl --system

Disable swap

free -h
swapoff -a
swapoff -a
sed -i.bak -r 's/(.+ swap .+)/#\1/' /etc/fstab
free -h

Install kubeadm

echo "runtime-endpoint: unix:///run/containerd/containerd.sock" > /etc/crictl.yaml
crictl ps

# Start containerd
systemctl enable --now containerd

apt-get install ebtables ethtool apt-transport-https

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF

Change runtime in kubeadm config:

nano /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
# add the following flags to KUBELET_KUBEADM_ARGS variable
Environment="KUBELET_KUBEADM_ARGS=--node-ip=192.168.1.41 --container-runtime=remote --container-runtime-endpoint=/run/containerd/containerd.sock --cgroup-driver=systemd"

apt-get update && apt-get install -y kubelet kubeadm kubectl
apt-mark hold kubelet kubeadm kubect
systemctl enable kubelet && systemctl start kubelet
kubeadm config images pul

Init master

kubeadm init --pod-network-cidr=10.244.0.0/16 \
--apiserver-advertise-address=192.168.1.41 \
--cri-socket=unix:///run/containerd/containerd.sock


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


kubectl apply -f https://github.com/coreos/flannel/raw/master/Documentation/kube-flannel.yml

Join workers to cluster

kubeadm join 192.168.1.41:6443 --token XXXXXXXX \
    --discovery-token-ca-cert-hash sha256:XXXXXXXX