kubernetes-v1.20.4 二進制部署-kube-apiserver

一、安裝部署kube-apiserver

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　　1、生成kube-apiserver證書，自簽證書頒發機構（CA）

cd ~/TLS/k8s
cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "175200h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "175200h",
         "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 -                      生成證書
ls *pem
ca-key.pem  ca.pem

　　2、創建證書申請文件，使用自簽CA簽發kube-apiserver HTTPS證書

cd ~/TLS/k8s
cat > server-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "192.168.112.110",
      "192.168.112.111",
      "192.168.112.112",
      "192.168.112.113",
      "192.168.112.114",
      "192.168.112.115",
      "192.168.112.120",
      "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       生成證書
ls server*pem
server-key.pem  server.pem

　　上述文件hosts字段中IP為所有Master/LB/VIP IP，一個都不能少！為了方便后期擴容可以多寫幾個預留的IP。

　　3、下載二進制包

下載地址： https://storage.googleapis.com/kubernetes-release/release/v1.20.4/kubernetes-server-linux-amd64.tar.gz

　　4、解壓二進制包

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

　　5、創建kube-apiserver配置文件

cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--etcd-servers=https://192.168.112.110:2379,https://192.168.112.111:2379,https://192.168.112.112:2379 \\
--bind-address=192.168.112.110 \\
--secure-port=6443 \\
--advertise-address=192.168.112.110 \\
--allow-privileged=true \\
--service-cluster-ip-range=10.0.0.0/24 \\
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \\
--authorization-mode=RBAC,Node \\
--enable-bootstrap-token-auth=true \\
--token-auth-file=/opt/kubernetes/cfg/token.csv \\
--service-node-port-range=30000-32767 \\
--kubelet-client-certificate=/opt/kubernetes/ssl/server.pem \\
--kubelet-client-key=/opt/kubernetes/ssl/server-key.pem \\
--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/kubernetes/ssl/etcd/ca.pem \\
--etcd-certfile=/opt/kubernetes/ssl/etcd/server.pem \\
--etcd-keyfile=/opt/kubernetes/ssl/etcd/server-key.pem \\
--service-account-issuer=api \\
--service-account-signing-key-file=/opt/kubernetes/ssl/server-key.pem \\
--requestheader-client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--proxy-client-cert-file=/opt/kubernetes/ssl/server.pem \\
--proxy-client-key-file=/opt/kubernetes/ssl/server-key.pem \\
--requestheader-allowed-names=kubernetes \\
--requestheader-extra-headers-prefix=X-Remote-Extra- \\
--requestheader-group-headers=X-Remote-Group \\
--requestheader-username-headers=X-Remote-User \\
--enable-aggregator-routing=true \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF

注：上面兩個\ \ 第一個是轉義符，第二個是換行符，使用轉義符是為了使用EOF保留換行符。

–logtostderr：啟用日志
—v：日志等級
–log-dir：日志目錄
–etcd-servers：etcd集群地址
–bind-address：監聽地址
–secure-port：https安全端口
–advertise-address：集群通告地址
–allow-privileged：啟用授權
–service-cluster-ip-range：Service虛擬IP地址段
–enable-admission-plugins：准入控制模塊
–authorization-mode：認證授權，啟用RBAC授權和節點自管理
–enable-bootstrap-token-auth：啟用TLS bootstrap機制
–token-auth-file：bootstrap token文件
–service-node-port-range：Service nodeport類型默認分配端口范圍
–kubelet-client-xxx：apiserver訪問kubelet客戶端證書
–tls-xxx-file：apiserver https證書
–etcd-xxxfile：連接Etcd集群證書
–audit-log-xxx：審計日志

　　6、拷貝剛才生成的證書

cp ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/

　　7、systemd管理apiserver

cat > /usr/lib/systemd/system/kube-apiserver.service << EOF
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-apiserver.conf
ExecStart=/opt/kubernetes/bin/kube-apiserver \$KUBE_APISERVER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF

　　8、啟用 TLS Bootstrapping 機制

　　TLS Bootstraping：Master apiserver啟用TLS認證后，Node節點kubelet和kube-proxy要與kube-apiserver進行通信，必須使用CA簽發的有效證書才可以，當Node節點很多時，這種客戶端證書頒發需要大量工作，同樣也會增加集群擴展復雜度。為了簡化流程，Kubernetes引入了TLS bootstraping機制來自動頒發客戶端證書，kubelet會以一個低權限用戶自動向apiserver申請證書，kubelet的證書由apiserver動態簽署。所以強烈建議在Node上使用這種方式，目前主要用於kubelet，kube-proxy還是由我們統一頒發一個證書。
TLS bootstraping 工作流程：

　　　　1）創建上述配置文件中token文件：

cat > /opt/kubernetes/cfg/token.csv << EOF
c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF

　　　　格式：token，用戶名，UID，用戶組，

　　　　token也可自行生成替換：

head -c 16 /dev/urandom | od -An -t x | tr -d ' '

　　　　2）簽發admin證書

cd ~/TLS/k8s
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
cp admin.pem admin-key.pem /opt/kubernetes/ssl

　　　　3）創建config文件

mkdir /root/.kube/  && cd  /root/.kube/

cat > config << EOF
apiVersion: v1
clusters:
- cluster:
    certificate-authority: /opt/kubernetes/ssl/ca.pem
    server: https://192.168.112.120:7443
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    user: admin
  name: default
current-context: default
kind: Config
preferences: {}
users:
- name: admin
  user:
    client-certificate: /opt/kubernetes/ssl/admin.pem
    client-key: /opt/kubernetes/ssl/admin-key.pem
EOF

　　9、拷貝安裝文件至另一台master節點上

scp -r /opt/kubernetes/ root@192.168.112.111:/opt
scp -r /root/.kube/config root@192.168.112.111:/root/.kube
scp /usr/lib/systemd/system/kube-apiserver.service root@192.168.112.111:/usr/lib/systemd/system/                    

　　注意：從節點記得修改kube-apiserver.conf中的主機IP地址

　　10、啟動並設置開機啟動

systemctl daemon-reload
systemctl start kube-apiserver systemctl enable kube-apiserver

二、安裝nginx和keepalived，對apiserver做高可用負載

　　1、在兩台master節點安裝nginx

　　　　1）編輯yum文件

vim /etc/yum.repos.d/nginx.repo

[nginx-stable]
name=nginx stable repo
baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true

[nginx-mainline]
name=nginx mainline repo
baseurl=http://nginx.org/packages/mainline/centos/$releasever/$basearch/
gpgcheck=1
enabled=0
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true

　　　　2）安裝最新版nginx

yum install nginx -y

　　2、編輯nginx配置文件，nginx四層負載，必須與http同級

vi /etc/nginx/nginx.conf

stream {
    upstream kube-apiserver {
        server 192.168.112.110:6443     max_fails=3 fail_timeout=30s;
        server 192.168.112.111:6443     max_fails=3 fail_timeout=30s;
    }
    server {
        listen 7443;
        proxy_connect_timeout 2s;
        proxy_timeout 900s;
        proxy_pass kube-apiserver;
    }
}

　　3、啟動nginx

nginx -t
systemctl start nginx
systemctl enable nginx

　　4、部署keepalived實現高可用

yum install keepalived -y

　　5、編寫keepalived監控腳本

vi /etc/keepalived/check_port.sh

#!/bin/bash
#keepalived 監控端口腳本
#使用方法：
#在keepalived的配置文件中
#vrrp_script check_port {#創建一個vrrp_script腳本,檢查配置
#    script "/etc/keepalived/check_port.sh 6379" #配置監聽的端口
#    interval 2 #檢查腳本的頻率,單位（秒）
#}
CHK_PORT=$1
if [ -n "$CHK_PORT" ];then
        PORT_PROCESS=`ss -lnt|grep $CHK_PORT|wc -l`
        if [ $PORT_PROCESS -eq 0 ];then
                echo "Port $CHK_PORT Is Not Used,End."
                exit 1
        fi
else
        echo "Check Port Cant Be Empty!"
fi

　　6、對監控腳本授權

chmod +x /etc/keepalived/check_port.sh

　　7、編輯keepalived配置文件，注意主從配置文件不一樣

vi /etc/keepalived/keepalived.conf
主：
! Configuration File for keepalived
 
global_defs {
   router_id 192.168.112.110
 
}
 
vrrp_script chk_nginx {
    script "/etc/keepalived/check_port.sh 7443"
    interval 2
    weight -20
}
 
vrrp_instance VI_1 {
    state MASTER
    interface ens192                       修改網卡名字
    virtual_router_id 251
    priority 100
    advert_int 1
    mcast_src_ip 192.168.112.110
    nopreempt   #非搶占式 ，當主節點掛了以后，從節點vip飄到從上，主節點恢復以后，不主動飄回主，需要手動重啟keepalived
 
    authentication {
        auth_type PASS
        auth_pass 11111111
    }
    track_script {
         chk_nginx
    }
    virtual_ipaddress {
        192.168.112.120
    }
}

從：
! Configuration File for keepalived
global_defs {
    router_id  192.168.112.111
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_port.sh 7443"
    interval 2
    weight -20
}
vrrp_instance VI_1 {
    state BACKUP
    interface ens192                     修改網卡名字
    virtual_router_id 251
    mcast_src_ip  192.168.112.111
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 11111111
    }
    track_script {
        chk_nginx
    }
    virtual_ipaddress {
        192.168.112.120
    }
}

　　8、啟動keepalived並配置開機自啟

systemctl start keepalived
systemctl enable keepalived

　　9、檢查VIP情況

　　

　　 如果keepalived出現腦裂問題，兩台上面都有vip，可以加入以下配置，將多播修改成單播

　　

 　  至此，apiserver部署完成，並且配置了負載高可用。

 　  10、授權kubelet-bootstrap用戶允許請求證書

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