kubeadm安装kubernets集群

# 关闭 防火墙
systemctl stop firewalld
systemctl disable firewalld

# 关闭 SeLinux
setenforce 0
sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config

# 关闭 swap
swapoff -a

# 修改 /etc/sysctl.conf

echo "net.ipv4.ip_forward = 1" >> /etc/sysctl.conf      ####开启路由转发
echo "net.bridge.bridge-nf-call-ip6tables = 1" >> /etc/sysctl.conf
echo "net.bridge.bridge-nf-call-iptables = 1" >> /etc/sysctl.conf
# 生效
sysctl -p

必须先安装 nfs-utils 才能挂载 nfs 网络存储
#yum install -y nfs-utils
#yum install -y wget

# step 1: 安装必要的一些系统工具
yum install -y yum-utils device-mapper-persistent-data lvm2
# Step 2: 添加软件源信息
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
# Step 3: 更新
yum makecache fast

#yum install -y docker-cedocker-ce-cl
#systemctl enable docker
#systemctl start docker

查看docker版本
#docker --version
Docker version 19.03.5, build 633a0ea

cat  /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

# yum install -y kubelet kubeadm kubectl
# systemctl enable kubelet && systemctl start kubelet
备注：此时kubelet启动失败  必须完成后面初始化操作后才可以启动

#vim /etc/docker/daemon.json
{
  "registry-mirrors": ["https://xxxxxx.mirror.aliyuncs.com"]
}
这里是去阿里云申请的镜像加速地址

sed -i "s#^ExecStart=/usr/bin/dockerd.*#ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock --exec-opt native.cgroupdriver=systemd#g" /usr/lib/systemd/system/docker.service
这步可以不做，如果没有修改，集群在初始化和worker节点加入的时候会爆出警告信息

echo "100.100.100.1    apiserver.shiji" >> /etc/hosts   ####注意这里不要用hostname

设置初始化配置文件
cat  ./kubeadm-config.yaml
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
kubernetesVersion: v1.17.0
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
controlPlaneEndpoint: "apiserver.shiji:6443"
networking:
  serviceSubnet: "10.20.0.0/16"
  podSubnet: "10.10.0.1/16"
  dnsDomain: "cluster.local"
EOF

注意对应参数，查看完整配置选项 https://godoc.org/k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta2

　　kubernetesVersion  集群版本， 使用 kubelet --version查看

　　controlPlaneEndpoint 

　　serviceSubnet   service网段

　　podSubnet　　pod网段

初始化集群，这里因为我的服务器cpu只有1核  所以忽略掉了cpu数量检测
kubeadm init --config=kubeadm-config.yaml --upload-certs --ignore-preflight-errors=NumCPU

To start using your cluster, you need to run the following as a 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

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of the control-plane node running the following command on each as root:

  kubeadm join apiserver.shiji:6443 --token pcubw3.uirtjhun4jau2hep     --discovery-token-ca-cert-hash sha256:4d40d0c79a56f0dc89a53547ecd1f320d903890046cd08c7c378fdaa9328c20f     --control-plane --certificate-key fbc40ce4548734ced1fcac892ef2ec70719816813783f####################

Please note that the certificate-key gives access to cluster sensitive data, keep it secret!
As a safeguard, uploaded-certs will be deleted in two hours; If necessary, you can use
"kubeadm init phase upload-certs --upload-certs" to reload certs afterward.

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join apiserver.shiji:6443 --token pcubw3.uirtjhun4jau2hep     --discovery-token-ca-cert-hash sha256:4d40d0c79a56f0dc89a53547ecd1f320d903890046################# 

# 配置 kubectl
 mkdir -p $HOME/.kube
 sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
 
#安装calico网络插件
wget https://docs.projectcalico.org/v3.9/manifests/calico.yaml
sed -i "s#192\.168\.0\.0/16#${POD_SUBNET}#" calico-3.9.2.yaml
kubectl apply -f calico.yaml

calico官方文档
https://docs.projectcalico.org/v3.9/getting-started/kubernetes/
关于几种网络插件的区别http://dockone.io/article/8722

# 执行如下命令，等待 3-10 分钟，直到所有的容器组处于 Running 状态
watch kubectl get pod -n kube-system -o wide

kubeadm join apiserver.shiji:6443 --token pcubw3.uirtjhun4jau2hep     --discovery-token-ca-cert-hash sha256:4d40d0c79a56f0dc89a53547ecd1f320d903890046#################