部署一套完整的Kubernetes高可用集羣（二進制，v1.18版）

時間 2020-07-22

標籤部署一套完整 kubernetes 可用集羣二進制 v1.18 欄目負載均衡简体版

原文原文鏈接

1、前置知識點

1.1 生產環境可部署Kubernetes集羣的兩種方式

目前生產部署Kubernetes集羣主要有兩種方式：node

kubeadm

Kubeadm是一個K8s部署工具，提供kubeadm init和kubeadm join，用於快速部署Kubernetes集羣。linux

官方地址：https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm/nginx

二進制包

從github下載發行版的二進制包，手動部署每一個組件，組成Kubernetes集羣。git

Kubeadm下降部署門檻，但屏蔽了不少細節，遇到問題很難排查。若是想更容易可控，推薦使用二進制包部署Kubernetes集羣，雖然手動部署麻煩點，期間能夠學習不少工做原理，也利於後期維護。github

1.2 安裝要求

在開始以前，部署Kubernetes集羣機器須要知足如下幾個條件：web

一臺或多臺機器，操做系統 CentOS7.x-86_x64
硬件配置：2GB或更多RAM，2個CPU或更多CPU，硬盤30GB或更多
能夠訪問外網，須要拉取鏡像，若是服務器不能上網，須要提早下載鏡像並導入節點
禁止swap分區

1.3 準備環境

軟件環境：算法

軟件	版本
操做系統	CentOS7.8_x64 （mini）
Docker	19-ce
Kubernetes	1.18

服務器總體規劃：docker

角色	IP	組件
k8s-master1	192.168.31.71	kube-apiserver，kube-controller-manager，kube-scheduler，etcd
k8s-master2	192.168.31.74	kube-apiserver，kube-controller-manager，kube-scheduler
k8s-node1	192.168.31.72	kubelet，kube-proxy，docker etcd
k8s-node2	192.168.31.73	kubelet，kube-proxy，docker，etcd
Load Balancer（Master）	192.168.31.81 ，192.168.31.88 (VIP)	Nginx L4
Load Balancer（Backup）	192.168.31. 82	Nginx L4

須知：考慮到有些朋友電腦配置較低，這麼多虛擬機跑不動，因此這一套高可用集羣分兩部分實施，先部署一套單Master架構（192.168.31.71/72/73），再擴容爲多Master架構（上述規劃），順便熟悉下Master擴容流程。數據庫

單Master架構圖：json

單Master服務器規劃：

角色	IP	組件
k8s-master	192.168.31.71	kube-apiserver，kube-controller-manager，kube-scheduler，etcd
k8s-node1	192.168.31.72	kubelet，kube-proxy，docker etcd
k8s-node2	192.168.31.73	kubelet，kube-proxy，docker，etcd

1.4 操做系統初始化配置

# 關閉防火牆
systemctl stop firewalld
systemctl disable firewalld

# 關閉selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
setenforce 0  # 臨時

# 關閉swap
swapoff -a  # 臨時
sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久

# 根據規劃設置主機名
hostnamectl set-hostname <hostname>

# 在master添加hosts
cat >> /etc/hosts << EOF
192.168.31.71 k8s-master
192.168.31.72 k8s-node1
192.168.31.73 k8s-node2
EOF

# 將橋接的IPv4流量傳遞到iptables的鏈
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system  # 生效

# 時間同步
yum install ntpdate -y
ntpdate time.windows.com

2、部署Etcd集羣

Etcd 是一個分佈式鍵值存儲系統，Kubernetes使用Etcd進行數據存儲，因此先準備一個Etcd數據庫，爲解決Etcd單點故障，應採用集羣方式部署，這裏使用3臺組建集羣，可容忍1臺機器故障，固然，你也可使用5臺組建集羣，可容忍2臺機器故障。

節點名稱	IP
etcd-1	192.168.31.71
etcd-2	192.168.31.72
etcd-3	192.168.31.73

注：爲了節省機器，這裏與K8s節點機器複用。也能夠獨立於k8s集羣以外部署，只要apiserver能鏈接到就行。

2.1 準備cfssl證書生成工具

cfssl是一個開源的證書管理工具，使用json文件生成證書，相比openssl更方便使用。

找任意一臺服務器操做，這裏用Master節點。

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

2.2 生成Etcd證書

1. 自簽證書頒發機構（CA）

建立工做目錄：

mkdir -p ~/TLS/{etcd,k8s}

cd TLS/etcd

自籤CA：

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

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

生成證書：

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

ls *pem
ca-key.pem  ca.pem

2. 使用自籤CA簽發Etcd HTTPS證書

建立證書申請文件：

cat > server-csr.json << EOF
{
    "CN": "etcd",
    "hosts": [
    "192.168.31.71",
    "192.168.31.72",
    "192.168.31.73"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing"
        }
    ]
}
EOF

注：上述文件hosts字段中IP爲全部etcd節點的集羣內部通訊IP，一個都不能少！爲了方便後期擴容能夠多寫幾個預留的IP。

生成證書：

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

ls server*pem
server-key.pem  server.pem

2.3 從Github下載二進制文件

下載地址：https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz

2.4 部署Etcd集羣

如下在節點1上操做，爲簡化操做，待會將節點1生成的全部文件拷貝到節點2和節點3.

1. 建立工做目錄並解壓二進制包

mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxvf etcd-v3.4.9-linux-amd64.tar.gz
mv etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

2. 建立etcd配置文件

cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.71:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF

ETCD_NAME：節點名稱，集羣中惟一
ETCD_DATA_DIR：數據目錄
ETCD_LISTEN_PEER_URLS：集羣通訊監聽地址
ETCD_LISTEN_CLIENT_URLS：客戶端訪問監聽地址
ETCD_INITIAL_ADVERTISE_PEER_URLS：集羣通告地址
ETCD_ADVERTISE_CLIENT_URLS：客戶端通告地址
ETCD_INITIAL_CLUSTER：集羣節點地址
ETCD_INITIAL_CLUSTER_TOKEN：集羣Token
ETCD_INITIAL_CLUSTER_STATE：加入集羣的當前狀態，new是新集羣，existing表示加入已有集羣

3. systemd管理etcd

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

[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd.conf
ExecStart=/opt/etcd/bin/etcd \
--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 \
--logger=zap
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

4. 拷貝剛纔生成的證書

把剛纔生成的證書拷貝到配置文件中的路徑：

cp ~/TLS/etcd/ca*pem ~/TLS/etcd/server*pem /opt/etcd/ssl/

5. 啓動並設置開機啓動

systemctl daemon-reload
systemctl start etcd
systemctl enable etcd

6. 將上面節點1全部生成的文件拷貝到節點2和節點3

scp -r /opt/etcd/ root@192.168.31.72:/opt/
scp /usr/lib/systemd/system/etcd.service root@192.168.31.72:/usr/lib/systemd/system/
scp -r /opt/etcd/ root@192.168.31.73:/opt/
scp /usr/lib/systemd/system/etcd.service root@192.168.31.73:/usr/lib/systemd/system/

而後在節點2和節點3分別修改etcd.conf配置文件中的節點名稱和當前服務器IP：

vi /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-1"   # 修改此處，節點2改成etcd-2，節點3改成etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.71:2380"   # 修改此處爲當前服務器IP
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379" # 修改此處爲當前服務器IP

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380" # 修改此處爲當前服務器IP
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379" # 修改此處爲當前服務器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

最後啓動etcd並設置開機啓動，同上。

7. 查看集羣狀態

ETCDCTL_API=3 /opt/etcd/bin/etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379" endpoint health

https://192.168.31.71:2379 is healthy: successfully committed proposal: took = 8.154404ms
https://192.168.31.73:2379 is healthy: successfully committed proposal: took = 9.044117ms
https://192.168.31.72:2379 is healthy: successfully committed proposal: took = 10.000825ms

若是輸出上面信息，就說明集羣部署成功。若是有問題第一步先看日誌：/var/log/message 或 journalctl -u etcd

3、安裝Docker

下載地址：https://download.docker.com/linux/static/stable/x86_64/docker-19.03.9.tgz

如下在全部節點操做。這裏採用二進制安裝，用yum安裝也同樣。

3.1 解壓二進制包

tar zxvf docker-19.03.9.tgz
mv docker/* /usr/bin

3.2 systemd管理docker

cat > /usr/lib/systemd/system/docker.service << EOF
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target

[Service]
Type=notify
ExecStart=/usr/bin/dockerd
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
EOF

3.3 建立配置文件

mkdir /etc/docker
cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF

registry-mirrors 阿里雲鏡像加速器

3.4 啓動並設置開機啓動

systemctl daemon-reload
systemctl start docker
systemctl enable docker

4、部署Master Node

若是你在學習中遇到問題或者文檔有誤可聯繫阿良~ 微信: init1024

4.1 生成kube-apiserver證書

1. 自簽證書頒發機構（CA）

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

生成證書：

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

ls *pem
ca-key.pem  ca.pem

2. 使用自籤CA簽發kube-apiserver HTTPS證書

建立證書申請文件：

cd TLS/k8s
cat > server-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "192.168.31.71",
      "192.168.31.72",
      "192.168.31.73",
      "192.168.31.74",
      "192.168.31.81",
      "192.168.31.82",
      "192.168.31.88",
      "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

注：上述文件hosts字段中IP爲全部Master/LB/VIP IP，一個都不能少！爲了方便後期擴容能夠多寫幾個預留的IP。

生成證書：

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

ls server*pem
server-key.pem  server.pem

4.2 從Github下載二進制文件

下載地址： https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#v1183

注：打開連接你會發現裏面有不少包，下載一個server包就夠了，包含了Master和Worker Node二進制文件。

4.3 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/

4.4 部署kube-apiserver

1. 建立配置文件

cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--etcd-servers=https://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379 \\
--bind-address=192.168.31.71 \\
--secure-port=6443 \\
--advertise-address=192.168.31.71 \\
--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/etcd/ssl/ca.pem \\
--etcd-certfile=/opt/etcd/ssl/server.pem \\
--etcd-keyfile=/opt/etcd/ssl/server-key.pem \\
--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，使用轉義符是爲了使用EOF保留換行符。

–logtostderr：啓用日誌
—v：日誌等級
–log-dir：日誌目錄
–etcd-servers：etcd集羣地址
–bind-address：監聽地址
–secure-port：https安全端口
–advertise-address：集羣通告地址
–allow-privileged：啓用受權
–service-cluster-ip-range：Service虛擬IP地址段
–enable-admission-plugins：准入控制模塊
–authorization-mode：認證受權，啓用RBAC受權和節點自管理
–enable-bootstrap-token-auth：啓用TLS bootstrap機制
–token-auth-file：bootstrap token文件
–service-node-port-range：Service nodeport類型默認分配端口範圍
–kubelet-client-xxx：apiserver訪問kubelet客戶端證書
–tls-xxx-file：apiserver https證書
–etcd-xxxfile：鏈接Etcd集羣證書
–audit-log-xxx：審計日誌

2. 拷貝剛纔生成的證書

把剛纔生成的證書拷貝到配置文件中的路徑：

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

3. 啓用 TLS Bootstrapping 機制

TLS Bootstraping：Master apiserver啓用TLS認證後，Node節點kubelet和kube-proxy要與kube-apiserver進行通訊，必須使用CA簽發的有效證書才能夠，當Node節點不少時，這種客戶端證書頒發須要大量工做，一樣也會增長集羣擴展複雜度。爲了簡化流程，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。因此強烈建議在Node上使用這種方式，目前主要用於kubelet，kube-proxy仍是由咱們統一頒發一個證書。

TLS bootstraping 工做流程：

建立上述配置文件中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 ' '

4. 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

5. 啓動並設置開機啓動

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

6. 受權kubelet-bootstrap用戶容許請求證書

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

4.5 部署kube-controller-manager

1. 建立配置文件

cat > /opt/kubernetes/cfg/kube-controller-manager.conf << EOF
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect=true \\
--master=127.0.0.1:8080 \\
--bind-address=127.0.0.1 \\
--allocate-node-cidrs=true \\
--cluster-cidr=10.244.0.0/16 \\
--service-cluster-ip-range=10.0.0.0/24 \\
--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 \\
--experimental-cluster-signing-duration=87600h0m0s"
EOF

–master：經過本地非安全本地端口8080鏈接apiserver。
–leader-elect：當該組件啓動多個時，自動選舉（HA）
–cluster-signing-cert-file/–cluster-signing-key-file：自動爲kubelet頒發證書的CA，與apiserver保持一致

2. systemd管理controller-manager

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

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

[Install]
WantedBy=multi-user.target
EOF

3. 啓動並設置開機啓動

systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager

4.6 部署kube-scheduler

1. 建立配置文件

cat > /opt/kubernetes/cfg/kube-scheduler.conf << EOF
KUBE_SCHEDULER_OPTS="--logtostderr=false \
--v=2 \
--log-dir=/opt/kubernetes/logs \
--leader-elect \
--master=127.0.0.1:8080 \
--bind-address=127.0.0.1"
EOF

–master：經過本地非安全本地端口8080鏈接apiserver。
–leader-elect：當該組件啓動多個時，自動選舉（HA）

2. systemd管理scheduler

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

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

[Install]
WantedBy=multi-user.target
EOF

3. 啓動並設置開機啓動

systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler

4. 查看集羣狀態

全部組件都已經啓動成功，經過kubectl工具查看當前集羣組件狀態：

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

如上輸出說明Master節點組件運行正常。

5、部署Worker Node

若是你在學習中遇到問題或者文檔有誤可聯繫阿良~ 微信: init1024

下面仍是在Master Node上操做，即同時做爲Worker Node

5.1 建立工做目錄並拷貝二進制文件

在全部worker node建立工做目錄：

mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}

從master節點拷貝：

cd kubernetes/server/bin
cp kubelet kube-proxy /opt/kubernetes/bin   # 本地拷貝

5.2 部署kubelet

1. 建立配置文件

cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-master \\
--network-plugin=cni \\
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \\
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \\
--config=/opt/kubernetes/cfg/kubelet-config.yml \\
--cert-dir=/opt/kubernetes/ssl \\
--pod-infra-container-image=lizhenliang/pause-amd64:3.0"
EOF

–hostname-override：顯示名稱，集羣中惟一
–network-plugin：啓用CNI
–kubeconfig：空路徑，會自動生成，後面用於鏈接apiserver
–bootstrap-kubeconfig：首次啓動向apiserver申請證書
–config：配置參數文件
–cert-dir：kubelet證書生成目錄
–pod-infra-container-image：管理Pod網絡容器的鏡像

2. 配置參數文件

cat > /opt/kubernetes/cfg/kubelet-config.yml << EOF
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 0.0.0.0
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS:
- 10.0.0.2
clusterDomain: cluster.local 
failSwapOn: false
authentication:
  anonymous:
    enabled: false
  webhook:
    cacheTTL: 2m0s
    enabled: true
  x509:
    clientCAFile: /opt/kubernetes/ssl/ca.pem 
authorization:
  mode: Webhook
  webhook:
    cacheAuthorizedTTL: 5m0s
    cacheUnauthorizedTTL: 30s
evictionHard:
  imagefs.available: 15%
  memory.available: 100Mi
  nodefs.available: 10%
  nodefs.inodesFree: 5%
maxOpenFiles: 1000000
maxPods: 110
EOF

3. 生成bootstrap.kubeconfig文件

KUBE_APISERVER="https://192.168.31.71:6443" # apiserver IP:PORT
TOKEN="c47ffb939f5ca36231d9e3121a252940" # 與token.csv裏保持一致

# 生成 kubelet bootstrap kubeconfig 配置文件
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=bootstrap.kubeconfig
kubectl config set-credentials "kubelet-bootstrap" \
  --token=${TOKEN} \
  --kubeconfig=bootstrap.kubeconfig
kubectl config set-context default \
  --cluster=kubernetes \
  --user="kubelet-bootstrap" \
  --kubeconfig=bootstrap.kubeconfig
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

拷貝到配置文件路徑：

cp bootstrap.kubeconfig /opt/kubernetes/cfg

4. systemd管理kubelet

cat > /usr/lib/systemd/system/kubelet.service << EOF
[Unit]
Description=Kubernetes Kubelet
After=docker.service

[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet.conf
ExecStart=/opt/kubernetes/bin/kubelet \$KUBELET_OPTS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

5. 啓動並設置開機啓動

systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet

5.3 批准kubelet證書申請並加入集羣

# 查看kubelet證書請求
kubectl get csr
NAME                                                   AGE    SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A   6m3s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 批准申請
kubectl certificate approve node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A

# 查看節點
kubectl get node
NAME         STATUS     ROLES    AGE   VERSION
k8s-master   NotReady   <none>   7s    v1.18.3

注：因爲網絡插件尚未部署，節點會沒有準備就緒 NotReady

5.4 部署kube-proxy

1. 建立配置文件

cat > /opt/kubernetes/cfg/kube-proxy.conf << EOF
KUBE_PROXY_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--config=/opt/kubernetes/cfg/kube-proxy-config.yml"
EOF

2. 配置參數文件

cat > /opt/kubernetes/cfg/kube-proxy-config.yml << EOF
kind: KubeProxyConfiguration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
metricsBindAddress: 0.0.0.0:10249
clientConnection:
  kubeconfig: /opt/kubernetes/cfg/kube-proxy.kubeconfig
hostnameOverride: k8s-master
clusterCIDR: 10.0.0.0/24
EOF

3. 生成kube-proxy.kubeconfig文件

生成kube-proxy證書：

# 切換工做目錄
cd TLS/k8s

# 建立證書請求文件
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

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

ls kube-proxy*pem
kube-proxy-key.pem  kube-proxy.pem

生成kubeconfig文件：

KUBE_APISERVER="https://192.168.31.71:6443"

kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/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

拷貝到配置文件指定路徑：

cp kube-proxy.kubeconfig /opt/kubernetes/cfg/

4. systemd管理kube-proxy

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

[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-proxy.conf
ExecStart=/opt/kubernetes/bin/kube-proxy \$KUBE_PROXY_OPTS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

5. 啓動並設置開機啓動

systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy

5.5 部署CNI網絡

先準備好CNI二進制文件：

下載地址：https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz

解壓二進制包並移動到默認工做目錄：

mkdir /opt/cni/bin
tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin

部署CNI網絡：

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
sed -i -r "s#quay.io/coreos/flannel:.*-amd64#lizhenliang/flannel:v0.12.0-amd64#g" kube-flannel.yml

默認鏡像地址沒法訪問，修改成docker hub鏡像倉庫。

kubectl apply -f kube-flannel.yml

kubectl get pods -n kube-system
NAME                          READY   STATUS    RESTARTS   AGE
kube-flannel-ds-amd64-2pc95   1/1     Running   0          72s

kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    <none>   41m   v1.18.3

部署好網絡插件，Node準備就緒。

5.6 受權apiserver訪問kubelet

cat > apiserver-to-kubelet-rbac.yaml << EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:kube-apiserver-to-kubelet
rules:
  - apiGroups:
      - ""
    resources:
      - nodes/proxy
      - nodes/stats
      - nodes/log
      - nodes/spec
      - nodes/metrics
      - pods/log
    verbs:
      - "*"
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: system:kube-apiserver
  namespace: ""
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:kube-apiserver-to-kubelet
subjects:
  - apiGroup: rbac.authorization.k8s.io
    kind: User
    name: kubernetes
EOF

kubectl apply -f apiserver-to-kubelet-rbac.yaml

5.7 新增長Worker Node

1. 拷貝已部署好的Node相關文件到新節點

在Master節點將Worker Node涉及文件拷貝到新節點192.168.31.72/73

scp /opt/kubernetes root@192.168.31.72:/opt/

scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.31.72:/usr/lib/systemd/system

scp -r /opt/cni/ root@192.168.31.72:/opt/

scp /opt/kubernetes/ssl/ca.pem root@192.168.31.72:/opt/kubernetes/ssl

2. 刪除kubelet證書和kubeconfig文件

rm /opt/kubernetes/cfg/kubelet.kubeconfig 
rm -f /opt/kubernetes/ssl/kubelet*

注：這幾個文件是證書申請審批後自動生成的，每一個Node不一樣，必須刪除從新生成。

3. 修改主機名

vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node1

vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-node1

4. 啓動並設置開機啓動

systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet
systemctl start kube-proxy
systemctl enable kube-proxy

5. 在Master上批准新Node kubelet證書申請

kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro   89s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

kubectl certificate approve node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro

6. 查看Node狀態

kubectl get node
NAME         STATUS     ROLES    AGE   VERSION
k8s-master   Ready      <none>   65m   v1.18.3
k8s-node1    Ready      <none>   12m   v1.18.3
k8s-node2    Ready      <none>   81s   v1.18.3

Node2（192.168.31.73 ）節點同上。記得修改主機名！

6、部署Dashboard和CoreDNS

6.1 部署Dashboard

$ wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta8/aio/deploy/recommended.yaml

默認Dashboard只能集羣內部訪問，修改Service爲NodePort類型，暴露到外部：

vi recommended.yaml
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001
  type: NodePort
  selector:
    k8s-app: kubernetes-dashboard

kubectl apply -f recommended.yaml

kubectl get pods,svc -n kubernetes-dashboard
NAME                                             READY   STATUS              RESTARTS   AGE
pod/dashboard-metrics-scraper-694557449d-z8gfb   1/1     Running             0          2m18s
pod/kubernetes-dashboard-9774cc786-q2gsx         1/1     Running             0          2m19s

NAME                                TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
service/dashboard-metrics-scraper   ClusterIP   10.0.0.141   <none>        8000/TCP        2m19s
service/kubernetes-dashboard        NodePort    10.0.0.239   <none>        443:30001/TCP   2m19s

訪問地址：https://NodeIP:30001

建立service account並綁定默認cluster-admin管理員集羣角色：

kubectl create serviceaccount dashboard-admin -n kube-system
kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')

使用輸出的token登陸Dashboard。

6.2 部署CoreDNS

CoreDNS用於集羣內部Service名稱解析。

kubectl apply -f coredns.yaml

kubectl get pods -n kube-system 
NAME                          READY   STATUS    RESTARTS   AGE
coredns-5ffbfd976d-j6shb      1/1     Running   0          32s
kube-flannel-ds-amd64-2pc95   1/1     Running   0          38m
kube-flannel-ds-amd64-7qhdx   1/1     Running   0          15m
kube-flannel-ds-amd64-99cr8   1/1     Running   0          26m

DNS解析測試：

kubectl run -it --rm dns-test --image=busybox:1.28.4 sh
If you don't see a command prompt, try pressing enter.

/ # nslookup kubernetes
Server:    10.0.0.2
Address 1: 10.0.0.2 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes
Address 1: 10.0.0.1 kubernetes.default.svc.cluster.local

解析沒問題。

7、高可用架構（擴容多Master架構）

Kubernetes做爲容器集羣系統，經過健康檢查+重啓策略實現了Pod故障自我修復能力，經過調度算法實現將Pod分佈式部署，並保持預期副本數，根據Node失效狀態自動在其餘Node拉起Pod，實現了應用層的高可用性。

針對Kubernetes集羣，高可用性還應包含如下兩個層面的考慮：Etcd數據庫的高可用性和Kubernetes Master組件的高可用性。而Etcd咱們已經採用3個節點組建集羣實現高可用，本節將對Master節點高可用進行說明和實施。

Master節點扮演着總控中心的角色，經過不斷與工做節點上的Kubelet和kube-proxy進行通訊來維護整個集羣的健康工做狀態。若是Master節點故障，將沒法使用kubectl工具或者API作任何集羣管理。

Master節點主要有三個服務kube-apiserver、kube-controller-manager和kube-scheduler，其中kube-controller-manager和kube-scheduler組件自身經過選擇機制已經實現了高可用，因此Master高可用主要針對kube-apiserver組件，而該組件是以HTTP API提供服務，所以對他高可用與Web服務器相似，增長負載均衡器對其負載均衡便可，而且可水平擴容。

多Master架構圖：

7.1 安裝Docker

同上，再也不贅述。

7.2 部署Master2 Node（192.168.31.74）

Master2 與已部署的Master1全部操做一致。因此咱們只需將Master1全部K8s文件拷貝過來，再修改下服務器IP和主機名啓動便可。

1. 建立etcd證書目錄

在Master2建立etcd證書目錄：

mkdir -p /opt/etcd/ssl

2. 拷貝文件（Master1操做）

拷貝Master1上全部K8s文件和etcd證書到Master2：

scp -r /opt/kubernetes root@192.168.31.74:/opt
scp -r /opt/cni/ root@192.168.31.74:/opt
scp -r /opt/etcd/ssl root@192.168.31.74:/opt/etcd
scp /usr/lib/systemd/system/kube* root@192.168.31.74:/usr/lib/systemd/system
scp /usr/bin/kubectl  root@192.168.31.74:/usr/bin

3. 刪除證書文件

刪除kubelet證書和kubeconfig文件：

rm -f /opt/kubernetes/cfg/kubelet.kubeconfig 
rm -f /opt/kubernetes/ssl/kubelet*

4. 修改配置文件IP和主機名

修改apiserver、kubelet和kube-proxy配置文件爲本地IP：

vi /opt/kubernetes/cfg/kube-apiserver.conf 
...
--bind-address=192.168.31.74 \
--advertise-address=192.168.31.74 \
...

vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-master2

vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-master2

5. 啓動設置開機啓動

systemctl daemon-reload
systemctl start kube-apiserver
systemctl start kube-controller-manager
systemctl start kube-scheduler
systemctl start kubelet
systemctl start kube-proxy
systemctl enable kube-apiserver
systemctl enable kube-controller-manager
systemctl enable kube-scheduler
systemctl enable kubelet
systemctl enable kube-proxy

6. 查看集羣狀態

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"}

7. 批准kubelet證書申請

kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU   85m   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

kubectl certificate approve node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU

kubectl get node
NAME          STATUS   ROLES    AGE   VERSION
k8s-master    Ready    <none>   34h   v1.18.3
k8s-master2   Ready    <none>   83m   v1.18.3
k8s-node1     Ready    <none>   33h   v1.18.3
k8s-node2     Ready    <none>   33h   v1.18.3

若是你在學習中遇到問題或者文檔有誤可聯繫阿良~ 微信: init1024

7.3 部署Nginx負載均衡器

kube-apiserver高可用架構圖：

Nginx是一個主流Web服務和反向代理服務器，這裏用四層實現對apiserver實現負載均衡。
Keepalived是一個主流高可用軟件，基於VIP綁定實現服務器雙機熱備，在上述拓撲中，Keepalived主要根據Nginx運行狀態判斷是否須要故障轉移（偏移VIP），例如當Nginx主節點掛掉，VIP會自動綁定在Nginx備節點，從而保證VIP一直可用，實現Nginx高可用。

1. 安裝軟件包（主/備）

yum install epel-release -y
yum install nginx keepalived -y

2. Nginx配置文件（主/備同樣）

cat > /etc/nginx/nginx.conf << "EOF"
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

include /usr/share/nginx/modules/*.conf;

events {
    worker_connections 1024;
}

# 四層負載均衡，爲兩臺Master apiserver組件提供負載均衡
stream {

    log_format  main  '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent';

    access_log  /var/log/nginx/k8s-access.log  main;

    upstream k8s-apiserver {
       server 192.168.31.71:6443;   # Master1 APISERVER IP:PORT
       server 192.168.31.74:6443;   # Master2 APISERVER IP:PORT
    }
    
    server {
       listen 6443;
       proxy_pass k8s-apiserver;
    }
}

http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;

    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;

    server {
        listen       80 default_server;
        server_name  _;

        location / {
        }
    }
}
EOF

3. keepalived配置文件（Nginx Master）

cat > /etc/keepalived/keepalived.conf << EOF
global_defs { 
   notification_email { 
     acassen@firewall.loc 
     failover@firewall.loc 
     sysadmin@firewall.loc 
   } 
   notification_email_from Alexandre.Cassen@firewall.loc  
   smtp_server 127.0.0.1 
   smtp_connect_timeout 30 
   router_id NGINX_MASTER
} 

vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}

vrrp_instance VI_1 { 
    state MASTER 
    interface ens33
    virtual_router_id 51 # VRRP 路由 ID實例，每一個實例是惟一的 
    priority 100    # 優先級，備服務器設置 90 
    advert_int 1    # 指定VRRP 心跳包通告間隔時間，默認1秒 
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    # 虛擬IP
    virtual_ipaddress { 
        192.168.31.88/24
    } 
    track_script {
        check_nginx
    } 
}
EOF

vrrp_script：指定檢查nginx工做狀態腳本（根據nginx狀態判斷是否故障轉移）
virtual_ipaddress：虛擬IP（VIP）

檢查nginx狀態腳本：

cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ps -ef |grep nginx |egrep -cv "grep|$$")

if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh

4. keepalived配置文件（Nginx Backup）

cat > /etc/keepalived/keepalived.conf << EOF
global_defs { 
   notification_email { 
     acassen@firewall.loc 
     failover@firewall.loc 
     sysadmin@firewall.loc 
   } 
   notification_email_from Alexandre.Cassen@firewall.loc  
   smtp_server 127.0.0.1 
   smtp_connect_timeout 30 
   router_id NGINX_BACKUP
} 

vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}

vrrp_instance VI_1 { 
    state BACKUP 
    interface ens33
    virtual_router_id 51 # VRRP 路由 ID實例，每一個實例是惟一的 
    priority 90
    advert_int 1
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    virtual_ipaddress { 
        192.168.31.88/24
    } 
    track_script {
        check_nginx
    } 
}
EOF

上述配置文件中檢查nginx運行狀態腳本：

cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ps -ef |grep nginx |egrep -cv "grep|$$")

if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh

注：keepalived根據腳本返回狀態碼（0爲工做正常，非0不正常）判斷是否故障轉移。

5. 啓動並設置開機啓動

systemctl daemon-reload
systemctl start nginx
systemctl start keepalived
systemctl enable nginx
systemctl enable keepalived

6. 查看keepalived工做狀態

ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:04:f7:2c brd ff:ff:ff:ff:ff:ff
    inet 192.168.31.80/24 brd 192.168.31.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.31.88/24 scope global secondary ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe04:f72c/64 scope link 
       valid_lft forever preferred_lft forever

能夠看到，在ens33網卡綁定了192.168.31.88 虛擬IP，說明工做正常。

7. Nginx+Keepalived高可用測試

關閉主節點Nginx，測試VIP是否漂移到備節點服務器。

在Nginx Master執行 pkill nginx
在Nginx Backup，ip addr命令查看已成功綁定VIP。

8. 訪問負載均衡器測試

找K8s集羣中任意一個節點，使用curl查看K8s版本測試，使用VIP訪問：

curl -k https://192.168.31.88:6443/version
{
  "major": "1",
  "minor": "18",
  "gitVersion": "v1.18.3",
  "gitCommit": "2e7996e3e2712684bc73f0dec0200d64eec7fe40",
  "gitTreeState": "clean",
  "buildDate": "2020-05-20T12:43:34Z",
  "goVersion": "go1.13.9",
  "compiler": "gc",
  "platform": "linux/amd64"
}

能夠正確獲取到K8s版本信息，說明負載均衡器搭建正常。該請求數據流程：curl -> vip(nginx) -> apiserver

經過查看Nginx日誌也能夠看到轉發apiserver IP：

tail /var/log/nginx/k8s-access.log -f
192.168.31.81 192.168.31.71:6443 - [30/May/2020:11:15:10 +0800] 200 422
192.168.31.81 192.168.31.74:6443 - [30/May/2020:11:15:26 +0800] 200 422

到此還沒結束，還有下面最關鍵的一步。

7.4 修改全部Worker Node鏈接LB VIP

試想下，雖然咱們增長了Master2和負載均衡器，可是咱們是從單Master架構擴容的，也就是說目前全部的Node組件鏈接都仍是Master1，若是不改成鏈接VIP走負載均衡器，那麼Master仍是單點故障。

所以接下來就是要改全部Node組件配置文件，由原來192.168.31.71修改成192.168.31.88（VIP）：

角色	IP
k8s-master1	192.168.31.71
k8s-master2	192.168.31.74
k8s-node1	192.168.31.72
k8s-node2	192.168.31.73

也就是經過kubectl get node命令查看到的節點。

在上述全部Worker Node執行：

sed -i 's#192.168.31.71:6443#192.168.31.88:6443#' /opt/kubernetes/cfg/*
systemctl restart kubelet
systemctl restart kube-proxy

檢查節點狀態：

kubectl get node
NAME          STATUS   ROLES    AGE    VERSION
k8s-master    Ready    <none>   34h    v1.18.3
k8s-master2   Ready    <none>   101m   v1.18.3
k8s-node1     Ready    <none>   33h    v1.18.3
k8s-node2     Ready    <none>   33h    v1.18.3

至此，一套完整的 Kubernetes 高可用集羣就部署完成了！

PS：若是你是在公有云上，通常都不支持keepalived，那麼你能夠直接用它們的負載均衡器產品（內網就行，還免費~），架構與上面同樣，直接負載均衡多臺Master kube-apiserver便可！