Kubernetes（k8s）单节点部署

一、单节点结构图

• 前文环境中最后部署了flannel网络组件，并实现了容器间的通信，本次实验，再之前基础上继续部署，实现k8s单节点架构，首先需要部署Master组件，也是核心组件：

① kube-apiserver

提供了资源操作的唯一入口，并提供认证授权，访问控制，API注册和发现等机制

② kube-controller-manager

负责维护集群的状态，比如故障检测，自动扩展，滚动更新等

③ kub-scheduler

负责资源的调度，按照预定的调度策略将Pod调度到相应的机器上（Model）

1.1 master节点apiserver 启动流程

kubelet ：基础的命令
① 我们在使用此命令的时，例如 kubelet get nodes 查看节点信息时首先会经过master 节点查看各个node点的业务信息，过程中需要bootstrap的授权（bootstrap.kubeconfig权限配置)
② 当有了以上的权限配置且通过以上权限许可之后才会去找apiserver进行操作
③ apiserver 首先会验证node节点中的令牌（token）
如果验证成功，则令牌会释放出其中的证书，将证书再次进行身份验证（CA验证），身份验证就需要通过csr的签名，签名成功之后，再给与对应的证书颁发，颁发许可之后才会启动apiserver、授权给与请求命令相对于的服务。（最终授权给bootstrap）
如果在以上的验证中有一部失败，apiserver则不会进行启动
④ Api会最终授权给bootstrap，而命令请求过来之后，必须要有bootstarp的授权才能进行，否则无法输出结果
我们在本次实例中，就需要生成apiserver的token、证书和签名，最后要将证书制作出来

二、部署master组件

2.1 master节点，生成证书

创建k8s工作目录和apiserver证书目录

[root@localhost k8s]# unzip master.zip

[root@localhost k8s]# mkdir /opt/kubernetes/{cfg,bin,ssl} -p
[root@localhost k8s]# mkdir k8s-cert

制作证书

#制作k8s-cert.sh 脚本
[root@localhost k8s]# cd k8s-cert
[root@localhost k8s-cert]# ls
k8s-cert.sh

#脚本内容

[root@localhost k8s-cert]# cat k8s-cert.sh
cat > ca-config.json <<EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF

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

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

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

cat > server-csr.json <<EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "192.168.126.10",			#master1节点
      "192.168.126.40",			#master2节点(为之后做多节点做准备)
      "192.168.126.88",			#VIP飘逸地址  虚拟ip地址
      "192.168.126.50",			#nginx1负载均衡地址(主)
      "192.168.126.60",			#nginx2负载均衡地址（备）
      "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"
        }
    ]
}
EOF

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

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

cat > admin-csr.json <<EOF
{
  "CN": "admin",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing",
      "O": "system:masters",
      "OU": "System"
    }
  ]
}
EOF

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

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

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

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

• 直接执行脚本生成K8S的证书

[root@localhost k8s-cert]# bash k8s-cert.sh

• 把ca server端的证书复制到k8s工作目录

[root@localhost k8s-cert]# cp ca*.pem server*.pem /opt/kubernetes/ssl
[root@localhost k8s-cert]# ls /opt/kubernetes/ssl/
ca-key.pem  ca.pem  server-key.pem  server.pem

2.2 生成token、绑定角色（bootstrap）

• 解压kubernetes压缩包

[root@localhost k8s]# tar zxvf kubernetes-server-linux-amd64.tar.gz
[root@localhost k8s]# cd /root/k8s/kubernetes/server/bin

[root@localhost k8s]ls

• 复制关键命令到k8s的工作目录中

[root@localhost bin]# cp kube-apiserver kubectl kube-controller-manager kube-scheduler /opt/kubernetes/bin/
[root@localhost k8s]# cd /root/k8s

//使用 head -c 16 /dev/urandom | od -An -t x | tr -d ’ ’ 可以随机生成序列号

```cpp
[root@localhost ~]#head -c 16 /dev/urandom | od -An -t x | tr -d ' '
9e44a17c3a738d4ae6c42d2c86fa848e
[root@localhost k8s]# vim /opt/kubernetes/cfg/token.csv
0fb61c46f8991b718eb38d27b605b008,kubelet-bootstrap,10001,"system:kubelet-bootstrap"
序列号，用户名，id，角色

此角色的定位和作用如下：
① 创建位置：在master节点创建bootstrap角色
② 管理node节点的kubelet
③ kubelet-bootstrap 管理、授权system：kubelet-bootstrap
④ 而system：kubelet-bootstrap 则管理node节点的kubelet
⑤ token就是授权给system：kubelet-bootstrap角色，如果此角色没有token的授权，则不能管理node下的kubelet

2.3 启动apiserver、scheduler、controller-manager服务

2.3.1 启动apiserver服务

• 二进制文件，token，证书都准备好，开启apiserver

[root@localhost k8s]# bash apiserver.sh 192.168.126.10 https://192.168.126.10:2379,https://192.168.126.20:2379,https://192.168.126.30:2379

Created symlink from /etc/systemd/system/multi-user.target.wants/kube-apiserver.service to /usr/lib/systemd/system/kube-apiserver.service.

• apiserver.sh 脚本简介

#!/bin/bash

MASTER_ADDRESS=$1					#本地地址
ETCD_SERVERS=$2						#群集

cat <<EOF >/opt/kubernetes/cfg/kube-apiserver		#生成配置文件到k8s工作目录

KUBE_APISERVER_OPTS="--logtostderr=true \\		#从ETCD读取、存入数据
--v=4 \\
--etcd-servers=${ETCD_SERVERS} \\
--bind-address=${MASTER_ADDRESS} \\			#绑定地址
--secure-port=6443 \\
--advertise-address=${MASTER_ADDRESS} \\		#master本地地址
--allow-privileged=true \\				#允许授权
--service-cluster-ip-range=10.0.0.0/24 \\
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \\				#plugin插件，包括命名空间中的插件、server端的授权
--authorization-mode=RBAC,Node \\			#使用RBAC模式验证node端
--kubelet-https=true \\					#允许对方使用https协议进行访问
--enable-bootstrap-token-auth \\			#开启bootstrap令牌授权
--token-auth-file=/opt/kubernetes/cfg/token.csv \\	#令牌文件路径
--service-node-port-range=30000-50000 \\		#开启的监听端口
#以下均为证书文件
--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"
EOF

cat <<EOF >/usr/lib/systemd/system/kube-apiserver.service		#服务启动脚本
[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
EOF

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

• 检查进程是否启动成功

ps aux | grep kube
systemctl status kube-apiserver.service

• 查看配置文件

[root@localhost k8s]# cat /opt/kubernetes/cfg/kube-apiserver 

KUBE_APISERVER_OPTS="--logtostderr=true \
--v=4 \
--etcd-servers=https://192.168.126.10:2379,https://192.168.126.20:2379,https://192.168.126.30:2379 \
--bind-address=192.168.126.10 \
--secure-port=6443 \
--advertise-address=192.168.126.10 \
--allow-privileged=true \
--service-cluster-ip-range=10.0.0.0/24 \
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \
--authorization-mode=RBAC,Node \
--kubelet-https=true \
--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"

• 查看进行端口是否开启

netstat -natp | grep 6443
tcp        0      0 192.168.126.10:6443     0.0.0.0:*               LISTEN      58269/kube-apiserve 
tcp        0      0 192.168.126.10:6443     192.168.126.10:44212    ESTABLISHED 58269/kube-apiserve 
tcp        0      0 192.168.126.10:44212    192.168.126.10:6443     ESTABLISHED 58269/kube-apiserve 
[root@localhost k8s]#netstat -natp | grep 8080
tcp        0      0 127.0.0.1:8080          0.0.0.0:*               LISTEN      58269/kube-apiserve 

2.3.2 启动scheduler服务

• 查看scheduler启动脚本

[root@localhost k8s]# vim scheduler.sh 

#!/bin/bash

MASTER_ADDRESS=$1

cat <<EOF >/opt/kubernetes/cfg/kube-scheduler

KUBE_SCHEDULER_OPTS="--logtostderr=true \\  #定义日志记录
--v=4 \\
--master=${MASTER_ADDRESS}:8080 \\			#定义master地址，指向8080端口
--leader-elect"						#定位为leader

EOF

cat <<EOF >/usr/lib/systemd/system/kube-scheduler.service					#定义启动脚本
[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
EOF

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

[root@localhost k8s]# ./scheduler.sh 127.0.0.1
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-scheduler.service to /usr/lib/systemd/system/kube-scheduler.service.
[root@localhost k8s]# ps aux | grep ku

2.3.3 启动controller-manager

[root@localhost k8s]# chmod +x controller-manager.sh 
[root@localhost k8s]# ./controller-manager.sh 127.0.0.1
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-controller-manager.service to /usr/lib/systemd/system/kube-controller-manager.service.

• 最后查看master节点状态

[root@localhost ~]#cd k8s/
[root@localhost k8s]#/opt/kubernetes/bin/kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-1               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"}   
etcd-0               Healthy   {"health":"true"} 

三、node节点部署

3.1 node1节点部署

• 首先，把master节点的kubelet、kube-proxy拷贝到node节点

[root@localhost bin]# scp kubelet kube-proxy root@192.168.126.20:/opt/kubernetes/bin/
root@192.168.126.20's password: 
kubelet                                                           100%  168MB  27.9MB/s   00:06    
kube-proxy                                                        100%   48MB  31.5MB/s   00:01    
[root@localhost bin]# scp kubelet kube-proxy root@192.168.126.30:/opt/kubernetes/bin/
root@192.168.126.30's password: 
kubelet                                                           100%  168MB  56.1MB/s   00:03    
kube-proxy                                                        100%   48MB  37.3MB/s   00:01 

• 在node1节点操作（复制node.zip到/root目录下再解压）

[root@localhost ~]# ls
anaconda-ks.cfg  flannel-v0.10.0-linux-amd64.tar.gz  node.zip   公共  视频  文档  音乐
flannel.sh       initial-setup-ks.cfg                README.md  模板  图片  下载  桌面
//解压node.zip，获得kubelet.sh  proxy.sh 
[root@localhost ~]# unzip node.zip 

• 回到master节点，进行kube配置（在配置node节点前必须要做的）

kube配置，是master与node节点相互通讯的前提

[root@localhost k8s]# mkdir kubeconfig
[root@localhost k8s]# cd kubeconfig
#上传kubeconfig.sh脚本
[root@localhost kubeconfig]# ls
kubeconfig.sh
[root@localhost kubeconfig]# mv kubeconfig.sh kubeconfig
[root@localhost kubeconfig]# vim kubeconfig         
APISERVER=$1
SSL_DIR=$2

# 创建kubelet bootstrapping kubeconfig 
export KUBE_APISERVER="https://$APISERVER:6443"

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

# 设置客户端认证参数
kubectl config set-credentials kubelet-bootstrap \
  --token=664f2017059d58e78f6cce2e47ef383b \		#仅修改此处令牌序列号，从/opt/kubernetes/cfg/token.csv中获取
  --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=$SSL_DIR/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=kube-proxy.kubeconfig

kubectl config set-credentials kube-proxy \
  --client-certificate=$SSL_DIR/kube-proxy.pem \
  --client-key=$SSL_DIR/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

• 设置环境变量

方式一：
[root@localhost kubeconfig]# export PATH=$PATH:/opt/kubernetes/bin/
方式二：
[root@localhost kubeconfig]# vim /etc/profile
export PATH=$PATH:/opt/kubernetes/bin/
[root@localhost kubeconfig]# source /etc/profile

#以上任意一种方式设置完成后，即可补全、使用kubectl命令

[root@localhost kubeconfig]# kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-1               Healthy   {"health":"true"}   
etcd-0               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"} 

• 生成配置文件

[root@localhost kubeconfig]# bash kubeconfig 192.168.126.10 /root/k8s/k8s-cert/
Cluster "kubernetes" set.
User "kubelet-bootstrap" set.
Context "default" created.
Switched to context "default".
Cluster "kubernetes" set.
User "kube-proxy" set.
Context "default" created.
Switched to context "default".
[root@localhost kubeconfig]# ls
bootstrap.kubeconfig  kubeconfig  kube-proxy.kubeconfig

• 拷贝配置文件到node节点

复制的这两个配置文件的作用就是能与master节点通信和被master节点控制

[root@localhost kubeconfig]# scp bootstrap.kubeconfig kube-proxy.kubeconfig root@192.168.126.20:/opt/kubernetes/cfg/
root@192.168.126.20's password: 
bootstrap.kubeconfig                                              100% 2169     2.1MB/s   00:00    
kube-proxy.kubeconfig                                             100% 6275     4.2MB/s   00:00    
[root@localhost kubeconfig]# scp bootstrap.kubeconfig kube-proxy.kubeconfig root@192.168.126.30:/opt/kubernetes/cfg/
root@192.168.126.30's password: 
bootstrap.kubeconfig                                              100% 2169     1.8MB/s   00:00    
kube-proxy.kubeconfig                                             100% 6275     5.3MB/s  

• 创建bootstrap角色赋予权限用于连接apiserver请求签名⭐⭐

只有bootstrap授权之后，node节点才算完整的添加到群集、可以被master节点所管理

[root@localhost kubeconfig]# kubectl create clusterrolebinding kubelet-bootstrap --clusterrole=system:node-bootstrapper --user=kubelet-bootstrap

• node1节点操作

• 执行kubelet脚本，用于请求连接master主机

[root@localhost ~]# bash kubelet.sh 192.168.126.20
Created symlink from /etc/systemd/system/multi-user.target.wants/kubelet.service to /usr/lib/systemd/system/kubelet.service.

• 检查kubelet服务启动

[root@localhost ~]# ps aux | grep kube
[root@localhost ~]# systemctl status  kubelet.service

• master上操作

检查到node01节点的请求

[root@localhost kubeconfig]# kubectl get csr
NAME                                                   AGE     REQUESTOR           CONDITION
node-csr-OOq8BS8KcwiCEh88HNMwZicsEWhfxe8wkOm-l42K838   4m27s   kubelet-bootstrap   Pending（等待集群给该节点颁发证书）

kubectl certificate approve node-csr-OOq8BS8KcwiCEh88HNMwZicsEWhfxe8wkOm-l42K838

• 继续查看证书状态

[root@localhost kubeconfig]#kubectl get csr
NAME                                                   AGE   REQUESTOR           CONDITION
node-csr--EUOthgGy7W-MjwY9vcL_-9q7yeGI61ZIlQuKiiWzQY   52m   kubelet-bootstrap   Approved,Issued（已经被允许加入群集）

• 查看群集节点，成功加入node01节点

  [root@localhost kubeconfig]# kubectl get node
  NAME              STATUS   ROLES    AGE    VERSION
  192.168.126.20   Ready    <none>   118s   v1.12.3

• 在node01节点操作，启动proxy服务

[root@localhost ~]# bash proxy.sh 192.168.126.20
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-proxy.service to /usr/lib/systemd/system/kube-proxy.service.
[root@localhost ~]# systemctl status kube-proxy.service

[root@localhost ~]#systemctl enable kube-proxy
[root@localhost ~]#systemctl enable kubelet

设置开机自启动

3.2 node02节点部署

• 在node01节点操作

把现成的/opt/kubernetes目录复制到其他节点进行修改即可
[root@localhost ~]# scp -r /opt/kubernetes/ root@192.168.126.30:/opt/

[root@localhost ~]# scp /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.126.30:/usr/lib/systemd/system/

• 在node02上操作，进行修改

首先删除复制过来的证书，等会node02会自行申请证书

[root@localhost ~]# cd /opt/kubernetes/ssl/
[root@localhost ssl]# rm -rf *

• 修改配置文件kubelet kubelet.config kube-proxy（三个配置文件）

[root@localhost ssl]# cd ../cfg/
[root@localhost cfg]# vim kubelet    #修改里面的ip地址为本机ip

KUBELET_OPTS="--logtostderr=true \
--v=4 \
--hostname-override=192.168.126.30 \
--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"

root@localhost cfg]# vim kubelet.config 
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 192.168.126.30
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS:

- 10.0.0.2
clusterDomain: cluster.local.
failSwapOn: false
authentication:
  anonymous:
    enabled: true

[root@localhost cfg]# vim kube-proxy
KUBE_PROXY_OPTS="--logtostderr=true \
--v=4 \
--hostname-override=192.168.126.30 \
--cluster-cidr=10.0.0.0/24 \
--proxy-mode=ipvs \
--kubeconfig=/opt/kubernetes/cfg/kube-proxy.kubeconfig"

• 启动服务

[root@localhost cfg]# systemctl start kubelet.service 
[root@localhost cfg]# systemctl enable kubelet.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kubelet.service to /usr/lib/systemd/system/kubelet.service.
[root@localhost cfg]# systemctl start kube-proxy.service 
[root@localhost cfg]# systemctl enable kube-proxy.service 
Created symlink from /etc/systemd/system/multi-user.target.wants/kube-proxy.service to /usr/lib/systemd/system/kube-proxy.service.

• 在master上操作查看请求

[root@localhost k8s]# kubectl get csr
NAME                                                   AGE   REQUESTOR           CONDITION
node-csr-OaH9HpIKh6AKlfdjEKm4C6aJ0UT_1YxNaa70yEAxnsU   15s   kubelet-bootstrap   Pending

[root@localhost k8s]# kubectl certificate approve node-csr-OaH9HpIKh6AKlfdjEKm4C6aJ0UT_1YxNaa70yEAxnsU
certificatesigningrequest.certificates.k8s.io/node-csr-OaH9HpIKh6AKlfdjEKm4C6aJ0UT_1YxNaa70yEAxnsU approved

• 查看群集中的节点

[root@localhost k8s]# kubectl get nodes
NAME              STATUS   ROLES    AGE   VERSION
192.168.126.20   Ready    <none>   21h   v1.12.3
192.168.126.30   Ready    <none>   37s   v1.12.3