k8s-master on centos7

setup.sh

# 0. SYSTEM INFO & CLUSTER ARCH
# CentOS 7
#
#    +------------+                                +-----------+
#    | k8s-master |>192.168.99.20 -- 192.168.99.21<| k8s-node1 |
#    +------------+                                +-----------+
#          v                                             v
#       internet                                      internet
#
# /etc/hosts
# 192.168.99.20 k8s-master
# 192.168.99.21 k8s-node1
#

# 1. INSTALL DOCKER
# refer: 
#   - [official-doc](https://kubernetes.io/docs/setup/cri/#docker)
#   - [repo-mirrors](https://www.jianshu.com/p/ad3c712e1d95)
#   - [registry-mirrors](https://blog.csdn.net/u010316188/article/details/79865451)

# add repo
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum makecache

# install the *right* version
yum install docker-ce-18.06.1.ce -y

# config docker
mkdir /etc/docker

cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2",
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ],
  "registry-mirrors": ["https://registry.docker-cn.com"]
}
EOF

mkdir -p /etc/systemd/system/docker.service.d

# restart docker
systemctl daemon-reload
systemctl restart docker
systemctl enable docker

# check docker
docker run hello-world

# 2. INSTALL KUBEADM
# refer:
#   - [official-doc](https://kubernetes.io/docs/setup/independent/install-kubeadm/)
#   - [repo-mirrors](https://www.jianshu.com/p/e43f5e848da1)

# config repo
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
exclude=kube*
EOF

# disable SELinux
setenforce 0
sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

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

# start
systemctl enable kubelet && systemctl start kubelet

# network issue
cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system


# 3. INIT KUBERNETES
# refer:
#   - [official-doc](https://kubernetes.io/docs/setup/independent/create-cluster-kubeadm/)
#   - [init-options-ip](https://www.jianshu.com/p/e43f5e848da1)

# init
kubeadm init --pod-network-cidr=192.168.99.0/24 --apiserver-advertise-address=192.168.99.20
# use weave addon
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

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

kubectl get nodes
kubectl get pods --all-namespaces

####### ssh k8s-node1 #########
# repeat until kubeadm init (not include)
kubeadm join 192.168.99.20:6443 --token gijxs5.w049ky73l5u8rbcm --discovery-token-ca-cert-hash sha256:293e4d09c2c1f580a4ec469443f70305bf0a7957bdc1cfaa933f78fd838d93bc