二进制部署 Kubernetes 集群

二进制部署 Kubernetes 集群

 

提供的几种Kubernetes部署方式

• minikube

Minikube是一个工具，可以在本地快速运行一个单点的Kubernetes，尝试Kubernetes或日常开发的用户使用。不能用于生产环境。

• kubeadm

Kubeadm也是一个工具，提供kubeadm init和kubeadm join指令，用于快速部署Kubernetes集群。

• 二进制包

从官方下载发行版的二进制包，手动部署每个组件，组成Kubernetes集群。

小结：
生产环境中部署Kubernetes集群，只有Kubeadm和二进制包可选，Kubeadm降低部署门槛，但屏蔽了很多细节，遇到问题很难排查。这里使用二进制包部署Kubernetes集群，也是比较推荐大家使用这种方式，虽然手动部署麻烦点，但学习很多工作原理，更有利于后期维护。

软件环境

软件	版本
操作系统	CentOS7.5_x64
Docker	18-ce
Kubernetes	1.12

服务器角色

角色	IP	组件
k8s-master	192.168.31.63	kube-apiserver，kube-controller-manager，kube-scheduler，etcd
k8s-node1	192.168.31.65	kubelet，kube-proxy，docker，flannel，etcd
k8s-node2	192.168.31.66	kubelet，kube-proxy，docker，flannel，etcd

架构图

1. 部署Etcd集群

使用cfssl来生成自签证书，先下载cfssl工具：

wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo

1.1 生成证书

创建以下三个文件：

# cat ca-config.json
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "www": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}

# cat ca-csr.json
{
    "CN": "etcd CA",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing"
        }
    ]
}

# cat server-csr.json
{
    "CN": "etcd",
    "hosts": [
    "192.168.31.63",
    "192.168.31.65",
    "192.168.31.66"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing"
        }
    ]
}

生成证书：

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server
# ls *pem
ca-key.pem  ca.pem  server-key.pem  server.pem

证书这块知道怎么生成、怎么用即可，建议暂时不必过多研究。

1.2 部署Etcd

二进制包下载地址：https://github.com/coreos/etcd/releases/tag/v3.2.12

以下部署步骤在规划的三个etcd节点操作一样，唯一不同的是etcd配置文件中的服务器IP要写当前的：

解压二进制包：

# mkdir /opt/etcd/{bin,cfg,ssl} -p
# tar zxvf etcd-v3.2.12-linux-amd64.tar.gz
# mv etcd-v3.2.12-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

创建etcd配置文件：

# cat /opt/etcd/cfg/etcd   
#[Member]
ETCD_NAME="etcd01"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.63:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.63:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.63:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.63:2379"
ETCD_INITIAL_CLUSTER="etcd01=https://192.168.31.63:2380,etcd02=https://192.168.31.65:2380,etcd03=https://192.168.31.66:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

• ETCD_NAME 节点名称

• ETCD_DATA_DIR 数据目录

• ETCD_LISTEN_PEER_URLS 集群通信监听地址

• ETCD_LISTEN_CLIENT_URLS 客户端访问监听地址

• ETCD_INITIAL_ADVERTISE_PEER_URLS 集群通告地址

• ETCD_ADVERTISE_CLIENT_URLS 客户端通告地址

• ETCD_INITIAL_CLUSTER 集群节点地址

• ETCD_INITIAL_CLUSTER_TOKEN 集群Token

• ETCD_INITIAL_CLUSTER_STATE 加入集群的当前状态，new是新集群，existing表示加入已有集群

systemd管理etcd：

# cat /usr/lib/systemd/system/etcd.service 
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd
ExecStart=/opt/etcd/bin/etcd 
--name=${ETCD_NAME} 
--data-dir=${ETCD_DATA_DIR} 
--listen-peer-urls=${ETCD_LISTEN_PEER_URLS} 
--listen-client-urls=${ETCD_LISTEN_CLIENT_URLS},http://127.0.0.1:2379 
--advertise-client-urls=${ETCD_ADVERTISE_CLIENT_URLS} 
--initial-advertise-peer-urls=${ETCD_INITIAL_ADVERTISE_PEER_URLS} 
--initial-cluster=${ETCD_INITIAL_CLUSTER} 
--initial-cluster-token=${ETCD_INITIAL_CLUSTER_TOKEN} 
--initial-cluster-state=new 
--cert-file=/opt/etcd/ssl/server.pem 
--key-file=/opt/etcd/ssl/server-key.pem 
--peer-cert-file=/opt/etcd/ssl/server.pem 
--peer-key-file=/opt/etcd/ssl/server-key.pem 
--trusted-ca-file=/opt/etcd/ssl/ca.pem 
--peer-trusted-ca-file=/opt/etcd/ssl/ca.pem
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

把刚才生成的证书拷贝到配置文件中的位置：

# cp ca*pem server*pem /opt/etcd/ssl

启动并设置开启启动：

# systemctl start etcd
# systemctl enable etcd

都部署完成后，检查etcd集群状态：

# /opt/etcd/bin/etcdctl 
--ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem 
--endpoints="https://192.168.31.63:2379,https://192.168.31.65:2379,https://192.168.31.66:2379" 
cluster-health
member 18218cfabd4e0dea is healthy: got healthy result from https://192.168.31.63:2379
member 541c1c40994c939b is healthy: got healthy result from https://192.168.31.65:2379
member a342ea2798d20705 is healthy: got healthy result from https://192.168.31.66:2379
cluster is healthy

如果输出上面信息，就说明集群部署成功。如果有问题第一步先看日志：/var/log/message 或 journalctl -u etcd

2. 在Node安装Docker

# yum install -y yum-utils device-mapper-persistent-data lvm2
# yum-config-manager 
    --add-repo 
    https://download.docker.com/linux/centos/docker-ce.repo
# yum install docker-ce -y
# curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s http://bc437cce.m.daocloud.io
# systemctl start docker
# systemctl enable docker

3. 部署Flannel网络

工作原理：

Falnnel要用etcd存储自身一个子网信息，所以要保证能成功连接Etcd，写入预定义子网段：

# /opt/etcd/bin/etcdctl 
--ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem 
--endpoints="https://192.168.31.63:2379,https://192.168.31.65:2379,https://192.168.31.66:2379" 
set /coreos.com/network/config  '{ "Network": "172.17.0.0/16", "Backend": {"Type": "vxlan"}}'

以下部署步骤在规划的每个node节点都操作。

下载二进制包：

# wget https://github.com/coreos/flannel/releases/download/v0.10.0/flannel-v0.10.0-linux-amd64.tar.gz
# tar zxvf flannel-v0.9.1-linux-amd64.tar.gz
# mv flanneld mk-docker-opts.sh /opt/kubernetes/bin

配置Flannel：

# cat /opt/kubernetes/cfg/flanneld
FLANNEL_OPTIONS="--etcd-endpoints=https://192.168.31.63:2379,https://192.168.31.65:2379,https://192.168.31.66:2379 -etcd-cafile=/opt/etcd/ssl/ca.pem -etcd-certfile=/opt/etcd/ssl/server.pem -etcd-keyfile=/opt/etcd/ssl/server-key.pem"

systemd管理Flannel：

# cat /usr/lib/systemd/system/flanneld.service
[Unit]
Description=Flanneld overlay address etcd agent
After=network-online.target network.target
Before=docker.service

[Service]
Type=notify
EnvironmentFile=/opt/kubernetes/cfg/flanneld
ExecStart=/opt/kubernetes/bin/flanneld --ip-masq $FLANNEL_OPTIONS
ExecStartPost=/opt/kubernetes/bin/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/subnet.env
Restart=on-failure

[Install]
WantedBy=multi-user.target

配置Docker启动指定子网段：

# cat /usr/lib/systemd/system/docker.service 

[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target

[Service]
Type=notify
EnvironmentFile=/run/flannel/subnet.env
ExecStart=/usr/bin/dockerd $DOCKER_NETWORK_OPTIONS
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TimeoutStartSec=0
Delegate=yes
KillMode=process
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s

[Install]
WantedBy=multi-user.target

重启flannel和docker：

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

检查是否生效：

# ps -ef |grep docker
root     20941     1  1 Jun28 ?        09:15:34 /usr/bin/dockerd --bip=172.17.34.1/24 --ip-masq=false --mtu=1450
# ip addr
3607: flannel.1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN 
    link/ether 8a:2e:3d:09:dd:82 brd ff:ff:ff:ff:ff:ff
    inet 172.17.34.0/32 scope global flannel.1
       valid_lft forever preferred_lft forever
3608: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UP 
    link/ether 02:42:31:8f:d3:02 brd ff:ff:ff:ff:ff:ff
    inet 172.17.34.1/24 brd 172.17.34.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:31ff:fe8f:d302/64 scope link 
       valid_lft forever preferred_lft forever

确保docker0与flannel.1在同一网段。
测试不同节点互通，在当前节点访问另一个Node节点docker0 IP：

# ping 172.17.58.1
PING 172.17.58.1 (172.17.58.1) 56(84) bytes of data.
64 bytes from 172.17.58.1: icmp_seq=1 ttl=64 time=0.263 ms
64 bytes from 172.17.58.1: icmp_seq=2 ttl=64 time=0.204 ms

如果能通说明Flannel部署成功。如果不通检查下日志：journalctl -u flannel

4. 在Master节点部署组件

在部署Kubernetes之前一定要确保etcd、flannel、docker是正常工作的，否则先解决问题再继续。

4.1 生成证书

创建CA证书：

# cat ca-config.json
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}

# cat ca-csr.json
{
    "CN": "kubernetes",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}

# cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

生成apiserver证书：

# cat server-csr.json
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "192.168.31.63",
      "kubernetes",
      "kubernetes.default",
      "kubernetes.default.svc",
      "kubernetes.default.svc.cluster",
      "kubernetes.default.svc.cluster.local"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server

生成kube-proxy证书：

# cat kube-proxy-csr.json
{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}

# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy

最终生成以下证书文件：

# ls *pem
ca-key.pem  ca.pem  kube-proxy-key.pem  kube-proxy.pem  server-key.pem  server.pem

4.2 部署apiserver组件

下载二进制包：https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.12.md

下载这个包（kubernetes-server-linux-amd64.tar.gz）就够了，包含了所需的所有组件。

# mkdir /opt/kubernetes/{bin,cfg,ssl} -p
# tar zxvf kubernetes-server-linux-amd64.tar.gz
# cd kubernetes/server/bin
# cp kube-apiserver kube-scheduler kube-controller-manager kubectl /opt/kubernetes/bin

创建token文件，用途后面会讲到：

# cat /opt/kubernetes/cfg/token.csv
674c457d4dcf2eefe4920d7dbb6b0ddc,kubelet-bootstrap,10001,"system:kubelet-bootstrap"

第一列：随机字符串，自己可生成
第二列：用户名
第三列：UID
第四列：用户组

创建apiserver配置文件：

# cat /opt/kubernetes/cfg/kube-apiserver 

KUBE_APISERVER_OPTS="--logtostderr=true 
--v=4 
--etcd-servers=https://192.168.31.63:2379,https://192.168.31.65:2379,https://192.168.31.66:2379 
--bind-address=192.168.31.63 
--secure-port=6443 
--advertise-address=192.168.31.63 
--allow-privileged=true 
--service-cluster-ip-range=10.0.0.0/24 
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota,NodeRestriction 
--authorization-mode=RBAC,Node 
--enable-bootstrap-token-auth 
--token-auth-file=/opt/kubernetes/cfg/token.csv 
--service-node-port-range=30000-50000 
--tls-cert-file=/opt/kubernetes/ssl/server.pem  
--tls-private-key-file=/opt/kubernetes/ssl/server-key.pem 
--client-ca-file=/opt/kubernetes/ssl/ca.pem 
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem 
--etcd-cafile=/opt/etcd/ssl/ca.pem 
--etcd-certfile=/opt/etcd/ssl/server.pem 
--etcd-keyfile=/opt/etcd/ssl/server-key.pem"

配置好前面生成的证书，确保能连接etcd。

参数说明：

• —logtostderr 启用日志

• —-v  日志等级

• —etcd-servers etcd集群地址

• —bind-address 监听地址

• —secure-port https安全端口

• —advertise-address 集群通告地址

• —allow-privileged 启用授权

• —service-cluster-ip-range Service虚拟IP地址段

• —enable-admission-plugins 准入控制模块

• —authorization-mode 认证授权，启用RBAC授权和节点自管理

• —enable-bootstrap-token-auth 启用TLS bootstrap功能，后面会讲到

• —token-auth-file  token文件

• —service-node-port-range Service Node类型默认分配端口范围

systemd管理apiserver：

# cat /usr/lib/systemd/system/kube-apiserver.service 
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-apiserver
ExecStart=/opt/kubernetes/bin/kube-apiserver $KUBE_APISERVER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target

启动：

# systemctl daemon-reload
# systemctl enable kube-apiserver
# systemctl restart kube-apiserver

4.3 部署scheduler组件

创建schduler配置文件：

# cat /opt/kubernetes/cfg/kube-scheduler 

KUBE_SCHEDULER_OPTS="--logtostderr=true 
--v=4 
--master=127.0.0.1:8080 
--leader-elect"

参数说明：

• —master  连接本地apiserver

• —leader-elect 当该组件启动多个时，自动选举（HA）

systemd管理schduler组件：

# cat /usr/lib/systemd/system/kube-scheduler.service 
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-scheduler
ExecStart=/opt/kubernetes/bin/kube-scheduler $KUBE_SCHEDULER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target

启动：

# systemctl daemon-reload
# systemctl enable kube-scheduler
# systemctl restart kube-scheduler

4.4 部署controller-manager组件

创建controller-manager配置文件：

# cat /opt/kubernetes/cfg/kube-controller-manager 
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=true 
--v=4 
--master=127.0.0.1:8080 
--leader-elect=true 
--address=127.0.0.1 
--service-cluster-ip-range=10.0.0.0/24 
--cluster-name=kubernetes 
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem 
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem  
--root-ca-file=/opt/kubernetes/ssl/ca.pem 
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem"

systemd管理controller-manager组件：

# cat /usr/lib/systemd/system/kube-controller-manager.service 
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-controller-manager
ExecStart=/opt/kubernetes/bin/kube-controller-manager $KUBE_CONTROLLER_MANAGER_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target

启动：

# systemctl daemon-reload
# systemctl enable kube-controller-manager
# systemctl restart kube-controller-manager

所有组件都已经启动成功，通过kubectl工具查看当前集群组件状态：

# /opt/kubernetes/bin/kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"}   
etcd-1               Healthy   {"health":"true"}   
controller-manager   Healthy   ok

如上输出说明组件都正常。

5. 在Node节点部署组件

Master apiserver启用TLS认证后，Node节点kubelet组件想要加入集群，必须使用CA签发的有效证书才能与apiserver通信，当Node节点很多时，签署证书是一件很繁琐的事情，因此有了TLS Bootstrapping机制，kubelet会以一个低权限用户自动向apiserver申请证书，kubelet的证书由apiserver动态签署。

认证大致工作流程如图所示：

5.1 将kubelet-bootstrap用户绑定到系统集群角色

kubectl create clusterrolebinding kubelet-bootstrap 
  --clusterrole=system:node-bootstrapper 
  --user=kubelet-bootstrap

5.2 创建kubeconfig文件

在生成kubernetes证书的目录下执行以下命令生成kubeconfig文件：

# 创建kubelet bootstrapping kubeconfig 
BOOTSTRAP_TOKEN=674c457d4dcf2eefe4920d7dbb6b0ddc
KUBE_APISERVER="https://192.168.31.63:6443"

# 设置集群参数
kubectl config set-cluster kubernetes 
  --certificate-authority=./ca.pem 
  --embed-certs=true 
  --server=${KUBE_APISERVER} 
  --kubeconfig=bootstrap.kubeconfig

# 设置客户端认证参数
kubectl config set-credentials kubelet-bootstrap 
  --token=${BOOTSTRAP_TOKEN} 
  --kubeconfig=bootstrap.kubeconfig

# 设置上下文参数
kubectl config set-context default 
  --cluster=kubernetes 
  --user=kubelet-bootstrap 
  --kubeconfig=bootstrap.kubeconfig

# 设置默认上下文
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

#----------------------

# 创建kube-proxy kubeconfig文件

kubectl config set-cluster kubernetes 
  --certificate-authority=./ca.pem 
  --embed-certs=true 
  --server=${KUBE_APISERVER} 
  --kubeconfig=kube-proxy.kubeconfig

kubectl config set-credentials kube-proxy 
  --client-certificate=./kube-proxy.pem 
  --client-key=./kube-proxy-key.pem 
  --embed-certs=true 
  --kubeconfig=kube-proxy.kubeconfig

kubectl config set-context default 
  --cluster=kubernetes 
  --user=kube-proxy 
  --kubeconfig=kube-proxy.kubeconfig

kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig

# ls
bootstrap.kubeconfig  kube-proxy.kubeconfig

将这两个文件拷贝到Node节点/opt/kubernetes/cfg目录下。

5.2 部署kubelet组件

将前面下载的二进制包中的kubelet和kube-proxy拷贝到/opt/kubernetes/bin目录下。

创建kubelet配置文件：

# cat /opt/kubernetes/cfg/kubelet
KUBELET_OPTS="--logtostderr=true 
--v=4 
--hostname-override=192.168.31.65 
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig 
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig 
--config=/opt/kubernetes/cfg/kubelet.config 
--cert-dir=/opt/kubernetes/ssl 
--pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0"

参数说明：

• —hostname-override 在集群中显示的主机名

• —kubeconfig 指定kubeconfig文件位置，会自动生成

• —bootstrap-kubeconfig 指定刚才生成的bootstrap.kubeconfig文件

• —cert-dir 颁发证书存放位置

• —pod-infra-container-image 管理Pod网络的镜像

其中/opt/kubernetes/cfg/kubelet.config配置文件如下：

kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 192.168.31.65
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS: ["10.0.0.2"]
clusterDomain: cluster.local.
failSwapOn: false
authentication:
  anonymous:
    enabled: true

systemd管理kubelet组件：

# cat /usr/lib/systemd/system/kubelet.service 
[Unit]
Description=Kubernetes Kubelet
After=docker.service
Requires=docker.service

[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet
ExecStart=/opt/kubernetes/bin/kubelet $KUBELET_OPTS
Restart=on-failure
KillMode=process

[Install]
WantedBy=multi-user.target

启动：

# systemctl daemon-reload
# systemctl enable kubelet
# systemctl restart kubelet

在Master审批Node加入集群：

启动后还没加入到集群中，需要手动允许该节点才可以。
在Master节点查看请求签名的Node：

# kubectl get csr
# kubectl certificate approve XXXX
# kubectl get node

5.3 部署kube-proxy组件

创建kube-proxy配置文件：

# cat /opt/kubernetes/cfg/kube-proxy
KUBE_PROXY_OPTS="--logtostderr=true 
--v=4 
--hostname-override=192.168.31.65 
--cluster-cidr=10.0.0.0/24 
--kubeconfig=/opt/kubernetes/cfg/kube-proxy.kubeconfig"

systemd管理kube-proxy组件：

# cat /usr/lib/systemd/system/kube-proxy.service 
[Unit]
Description=Kubernetes Proxy
After=network.target

[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-proxy
ExecStart=/opt/kubernetes/bin/kube-proxy $KUBE_PROXY_OPTS
Restart=on-failure

[Install]
WantedBy=multi-user.target

启动：

# systemctl daemon-reload
# systemctl enable kube-proxy
# systemctl restart kube-proxy

Node2部署方式一样。

6. 查看集群状态

# kubectl get node
NAME             STATUS    ROLES     AGE       VERSION
192.168.31.65   Ready     <none>    1d       v1.12.0
192.168.31.66   Ready     <none>    1d       v1.12.0
# kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
controller-manager   Healthy   ok                  
scheduler            Healthy   ok                  
etcd-2               Healthy   {"health":"true"}   
etcd-1               Healthy   {"health":"true"}   
etcd-0               Healthy   {"health":"true"}

7. 运行一个测试示例

创建一个Nginx Web，测试集群是否正常工作：

# kubectl run nginx --image=nginx --replicas=3
# kubectl expose deployment nginx --port=88 --target-port=80 --type=NodePort

查看Pod，Service：

# kubectl get pods
NAME                     READY     STATUS    RESTARTS   AGE
nginx-64f497f8fd-fjgt2   1/1       Running   3          1d
nginx-64f497f8fd-gmstq   1/1       Running   3          1d
nginx-64f497f8fd-q6wk9   1/1       Running   3          1d
# kubectl get svc
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                        AGE
kubernetes   ClusterIP   10.0.0.1     <none>        443/TCP                        28d
nginx        NodePort    10.0.0.175   <none>        88:38696/TCP                   28d

访问集群中部署的Nginx，打开浏览器输入：http://192.168.31.66:38696