## Install Kubernetes on CENTOS

### Step1: `On All Machines ( Master & All nodes ):`

### Set SELinux in permissive mode (effectively disabling it)

setenforce 0

sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

### Install Docker

sudo yum remove -y docker docker-client docker-client-latest docker-common docker-latest docker-latest-logrotate docker-logrotate docker-engine docker-ce docker-ce-cli containerd.io

sudo yum install -y yum-utils device-mapper-persistent-data lvm2

sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

sudo yum install -y docker-ce docker-ce-cli containerd.io

systemctl enable --now docker

systemctl start docker

### Install kubeadm,kubelet,kubectl

cat <<EOF > /etc/yum.repos.d/kubernetes.repo

[kubernetes]

name=Kubernetes

baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64

enabled=1

gpgcheck=1

repo_gpgcheck=1

gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg

EOF

yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes

systemctl enable --now kubelet

### Step2: `On Master only:`

sudo kubeadm init --ignore-preflight-errors=all

sudo mkdir -p $HOME/.kube

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

sudo chown $(id -u):$(id -g) $HOME/.kube/config

## Weave Pod Network

kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

kubectl get nodes

kubectl get all --all-namespaces

### Step3: `On Nodes only:`

copy the kubeadm join token from master & run it on all nodes

Ex: kubeadm join 10.128.15.231:6443 --token mks3y2.v03tyyru0gy12mbt \

--discovery-token-ca-cert-hash sha256:3de23d42c7002be0893339fbe558ee75e14399e11f22e3f0b34351077b7c4b56