# How to Install Kubernetes Cluster
###### tags: `Kubernetes`

## Basic Setup

sudo apt update
sudo apt upgrade -y

## Turn off swap

sudo swapoff -a

vim /etc/fstab
#/swap.img none swap sw 0 0

reboot

## set up ipvs
`sudo vim /etc/modules-load.d/modules.conf`

> add this:

ip_vs_sh
ip_vs_wrr
ip_vs_rr
ip_vs
nf_conntrack

sudo reboot

## Install Docker

sudo apt install apt-transport-https ca-certificates software-properties-common -y
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo apt-key fingerprint 0EBFCD88
sudo add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
   $(lsb_release -cs) \
   stable"
sudo apt update && sudo apt install docker-ce -y

sudo pkill -SIGHUP dockerd
sudo groupadd docker
sudo usermod -aG docker $USER

## config docker

sudo vim /etc/docker/daemon.json

> add this:

{
    "exec-opts":["native.cgroupdriver=systemd"],
    "log-driver": "json-file",
    "log-opts": {
        "max-size": "100m"
    }
}

sudo service docker restart

## Install docker compose

sudo curl -L "https://github.com/docker/compose/releases/download/1.26.1/docker-compose-$(uname -s)-$(uname -m)" -o /usr/bin/docker-compose
sudo chmod +x /usr/bin/docker-compose

## Install K8S

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add
sudo apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main"
sudo apt-get install kubeadm kubelet kubectl -y

## Init Master

sudo kubeadm init --apiserver-advertise-address=<IP>  --pod-network-cidr=10.244.0.0/16
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

## Join Node
> Copy the message from your master when init your master node.

sudo kubeadm join 192.168.1.122:6443 --token 7uoe87.ollkkhqjbylca8go \
    --discovery-token-ca-cert-hash sha256:970a5280b98543c86e4c7f91d603fc9d4bc667cfe675d5de2e0081f910767ca4

## Deploy Flannel

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

## Reference
### Install
> https://blog.51cto.com/wutengfei/2121202

### flannel
> https://zhang0peter.com/2020/01/30/k8s-install-and-use-and-fix-bug/#flannel-masternode