09、K8s实战：通过RPM安装KubernetesHA集群-程序员快看-教程，程序员编程资料站

一、前言

高可用的Kubernetes集群会有3个master节点，运行3个APIServer实例，这三个APIServer实例可以挂载再同一个负载均衡器后端，实现高可用。

转载自https://blog.csdn.net/cloudvtech

二、测试集群主机准备

2.1 测试环境主机角色分配

3 kubernetes masters

192.168.56.101 (k8s-master-01)

192.168.56.102 (k8s-master-02)

192.168.56.103 (k8s-master-03)

1 kubernetes node

192.168.56.111 (k8s-node-01)

1 load balancer for 3 API servers

192.168.56.100

1 etcd cluster with 3 etcd servers running in 192.168.56.101/102/103

etcd集群的安装参看文章《Kubernetes生产实践系列之四：基于虚拟机部署安全加密的etcd集群》

2.2 安全和DNS准备

systemctl stop firewalld
systemctl disable firewalld

SELINUX=disabled
setenforce 0

/etc/ssh/sshd_config 
UseDNS no

2.3 集群证书准备

k8s-root-ca-csr.json

{
  "CN": "kubernetes",
  "key": {
    "algo": "rsa",
    "size": 4096
  },
  "names": [
    {
      "C": "CN",
      "ST": "Shanghai",
      "L": "Shanghai",
      "O": "k8s",
      "OU": "System"
    }
  ]
}

k8s-gencert.json

{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
        "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ],
        "expiry": "87600h"
      }
    }
  }
}

kubernetes-csr.json

{
    "CN": "kubernetes",
    "hosts": [
        "127.0.0.1",
        "10.254.0.1",
        "192.168.56.101",
        "192.168.56.100",
        "192.168.56.104",
        "192.168.56.105",
        "192.168.56.106",
        "192.168.56.102",
        "192.168.56.103",
        "192.168.56.111",
        "192.168.56.112",
        "192.168.56.113",
        "192.168.56.114",
        "192.168.56.115",
        "192.168.56.116",
        "192.168.56.117",
        "localhost",
        "kubernetes",
        "kubernetes.default",
        "kubernetes.default.svc",
        "kubernetes.default.svc.cluster",
        "kubernetes.default.svc.cluster.local",
        "k8s-master-01",
        "k8s-master-02",
        "k8s-master-03",
        "k8s-master-04",
        "k8s-master-05",
        "k8s-master-06",
        "k8s-node-01",
        "k8s-node-02",
        "k8s-node-03",
        "k8s-node-04",
        "k8s-node-05",
        "k8s-node-06",
        "k8s-node-07"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "ST": "Shanghai",
            "L": "Shanghai",
            "O": "k8s",
            "OU": "System"
        }
    ]
}

kube-proxy-csr.json

{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "Shanghai",
      "L": "Shanghai",
      "O": "k8s",
      "OU": "System"
    }
  ]
}

生成不同组建(kubernetes，admin，kube-proxy)使用的证书和key

cfssl gencert --initca=true k8s-root-ca-csr.json | cfssljson --bare k8s-root-ca

for targetName in kubernetes admin kube-proxy; do
    cfssl gencert --ca k8s-root-ca.pem --ca-key k8s-root-ca-key.pem --config k8s-gencert.json --profile kubernetes $targetName-csr.json | cfssljson --bare $targetName
done

openssl x509 -in kubernetes.pem -text

[root@k8s-tools k8s-ca]# ls -l
-rw-r--r--. 1 root root 1013 Oct 31 00:31 admin.csr
-rw-r--r--. 1 root root  231 Oct 30 02:56 admin-csr.json
-rw-------. 1 root root 1675 Oct 31 00:31 admin-key.pem
-rw-r--r--. 1 root root 1753 Oct 31 00:31 admin.pem
-rw-r--r--. 1 root root  292 Oct 30 02:53 k8s-gencert.json
-rw-r--r--. 1 root root 1695 Oct 31 00:31 k8s-root-ca.csr
-rw-r--r--. 1 root root  210 Oct 30 02:53 k8s-root-ca-csr.json
-rw-------. 1 root root 3243 Oct 31 00:31 k8s-root-ca-key.pem
-rw-r--r--. 1 root root 2057 Oct 31 00:31 k8s-root-ca.pem
-rw-r--r--. 1 root root 1013 Oct 31 00:31 kube-proxy.csr
-rw-r--r--. 1 root root  232 Oct 30 02:56 kube-proxy-csr.json
-rw-------. 1 root root 1679 Oct 31 00:31 kube-proxy-key.pem
-rw-r--r--. 1 root root 1753 Oct 31 00:31 kube-proxy.pem
-rw-r--r--. 1 root root 1622 Oct 31 00:31 kubernetes.csr
-rw-r--r--. 1 root root 1202 Oct 31 00:31 kubernetes-csr.json
-rw-------. 1 root root 1675 Oct 31 00:31 kubernetes-key.pem
-rw-r--r--. 1 root root 2334 Oct 31 00:31 kubernetes.pem

2.4 生成token和kubeconfig

要确保生成的kubeconfig里面带有APIServer 前端LB的地址

server: https://192.168.56.100:6443

export BOOTSTRAP_TOKEN=$(head -c 16 /dev/urandom | od -An -t x | tr -d ' ')
cat > token.csv <<EOF
${BOOTSTRAP_TOKEN},kubelet-bootstrap,10001,"system:kubelet-bootstrap"
EOF

每个节点kubelet连接APIServer LB使用的bootstrap.kubeconfig

export KUBE_APISERVER="https://192.168.56