二进制部署Kubernetes高可用集群

二进制部署Kubernetes高可用集群

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环境配置

Kubernetes部署方式

生产环境可部署Kubernetes集群的两种方式
kubeadm
Kubeadm是一个K8s部署工具,提供kubeadm init和kubeadm join,用于快速部署Kubernetes集群
官方地址:https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm/
二进制包
从github下载发行版的二进制包,手动部署每个组件,组成Kubernetes集群
Kubeadm降低部署门槛,但屏蔽了很多细节,遇到问题很难排查。如果想更容易可控,推荐使用二进制包部署Kubernetes集群,虽然手动部署麻烦点,期间可以学习很多工作原理,也利于后期维护

部署要求

部署Kubernetes集群机器需要满足以下几个条件:

  1. 一台或多台机器,操作系统 CentOS7.x-86_x64
  2. 硬件配置:2GB或更多RAM,2个CPU或更多CPU,硬盘30GB或更多
  3. 可以访问外网,需要拉取镜像,如果服务器不能上网,需要提前下载镜像并导入节点
  4. 禁止swap分区

环境准备

软件环境:

软件版本
操作系统CentOS7.8_x64
Docker19-ce
Kubernetes1.18

服务器整体规划:

角色IP组件
k8s-master1192.168.200.71kube-apiserver,kube-controller-manager,kube-scheduler,etcd
k8s-master2192.168.200.72kube-apiserver,kube-controller-manager,kube-scheduler
k8s-master2192.168.200.73kube-apiserver,kube-controller-manager,kube-scheduler
k8s-node1192.168.200.74kubelet,kube-proxy,docker etcd
k8s-node2192.168.200.75kubelet,kube-proxy,docker,etcd
Load Balancer(Master)192.168.200.76,192.168.200.77(VIP)Nginx L4
Load Balancer(Backup)192.168.200.78nginx L4

由于机器原因就没按照原计划的3master,5node节点部署,不过后续可根据相应进行扩容

多master架构图

高可用多master架构_wps图片.jpg

操作系统初始化配置

所有节点执行

# 关闭防火墙
[root@k8s-master1 ~]# systemctl stop firewalld
[root@k8s-master1 ~]# systemctl disable firewalld

# 关闭selinux
[root@k8s-master1 ~]# sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
[root@k8s-master1 ~]# setenforce 0  # 临时

# 关闭swap
[root@k8s-master1 ~]# swapoff -a  # 临时
[root@k8s-master1 ~]# sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久

# 根据规划设置主机名
[root@k8s-master1 ~]# hostnamectl set-hostname <hostname>

# 在master添加hosts
[root@k8s-master1 ~]# cat >> /etc/hosts << EOF
192.168.200.71 k8s-master1
192.168.200.72 k8s-master2
192.168.200.73 k8s-master3
192.168.200.74 k8s-node1
192.168.200.75 k8s-node2
EOF

# 将桥接的IPv4流量传递到iptables的链
[root@k8s-master1 ~]# cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
[root@k8s-master1 ~]# sysctl --system  # 生效

# 时间同步
[root@k8s-master1 ~]# yum install ntpdate -y
[root@k8s-master1 ~]# ntpdate time.windows.com

部署Etcd集群

Etcd 是一个分布式键值存储系统,Kubernetes使用Etcd进行数据存储,所以先准备一个Etcd数据库,为解决Etcd单点故障,应采用集群方式部署,这里使用3台组建集群,可容忍1台机器故障,当然,你也可以使用5台组建集群,可容忍2台机器故障

节点名称IP
etcd-1192.168.200.71
etcd-2192.168.200.72
etcd-3192.168.200.73

准备cfssl证书生成工具

cfssl是一个开源的证书管理工具,使用json文件生成证书,相比openssl更方便使用

[root@k8s-master1 ~]# wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
[root@k8s-master1 ~]# wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
[root@k8s-master1 ~]# wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
[root@k8s-master1 ~]# chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
[root@k8s-master1 ~]# mv cfssl_linux-amd64 /usr/local/bin/cfssl
[root@k8s-master1 ~]# mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
[root@k8s-master1 ~]# mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo

生成Etcd证书

自签证书颁发机构(CA)

创建工作目录:

[root@k8s-master1 ~]# mkdir -p ~/TLS/{etcd,k8s}
[root@k8s-master1 ~]# cd TLS/etcd

自签CA:

[root@k8s-master1 ~]# cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "www": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF

[root@k8s-master1 ~]# cat > ca-csr.json << EOF
{
    "CN": "etcd CA",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing"
        }
    ]
}
EOF

生成证书:

[root@k8s-master1 ~]# cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

[root@k8s-master1 ~]# ls *pem
ca-key.pem  ca.pem

使用自签CA签发Etcd HTTPS证书

创建证书申请文件:

[root@k8s-master1 ~]# cat > server-csr.json << EOF
{
    "CN": "etcd",
    "hosts": [
    "192.168.200.71",
    "192.168.200.72",
    "192.168.200.73"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing"
        }
    ]
}
EOF

注:上述文件hosts字段中IP为所有etcd节点的集群内部通信IP,一个都不能少!为了方便后期扩容可以多写几个预留的IP
生成证书:

[root@k8s-master1 ~]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server
[root@k8s-master1 ~]# ls server*pem
[root@k8s-master1 ~]# server-key.pem  server.pem

下载二进制文件

[root@k8s-master1 ~]# wget https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz

部署Etcd集群

以下在etcd-1上操作,为简化操作,待会将etcd-1生成的所有文件拷贝到etcd-2和etcd-3

创建工作目录并解压二进制包

[root@k8s-master1 ~]# mkdir /opt/etcd/{bin,cfg,ssl} -p
[root@k8s-master1 ~]# tar zxvf etcd-v3.4.9-linux-amd64.tar.gz
[root@k8s-master1 ~]# mv etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

创建etcd配置文件

[root@k8s-master1 ~]# 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://192.168.200.71:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.200.71:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.200.71:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.200.71:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.200.71:2380,etcd-2=https://192.168.200.72:2380,etcd-3=https://192.168.200.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF

ETCD_NAME:节点名称,集群中唯一
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

[root@k8s-master1 ~]# 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

拷贝刚才生成的证书

把刚才生成的证书拷贝到配置文件中的路径:

[root@k8s-master1 ~]# cp ~/TLS/etcd/ca*pem ~/TLS/etcd/server*pem /opt/etcd/ssl/

启动并设置开机启动

[root@k8s-master1 ~]# systemctl daemon-reload
[root@k8s-master1 ~]# systemctl start etcd
[root@k8s-master1 ~]# systemctl enable etcd

将上面etcd-1所有生成的文件拷贝到etcd-2和etcd-3

[root@k8s-master1 ~]# scp -r /opt/etcd/ root@192.168.200.72:/opt/
[root@k8s-master1 ~]# scp /usr/lib/systemd/system/etcd.service root@192.168.200.72:/usr/lib/systemd/system/
[root@k8s-master1 ~]# scp -r /opt/etcd/ root@192.168.200.73:/opt/
[root@k8s-master1 ~]# scp /usr/lib/systemd/system/etcd.service root@192.168.200.73:/usr/lib/systemd/system/

然后在etcd-2和etcd-3分别修改etcd.conf配置文件中的节点名称和当前服务器IP:

[root@k8s-master2 ~]# vi /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-1"   # 修改此处,节点2改为etcd-2,节点3改为etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.200.71:2380"   # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://192.168.200.71:2379" # 修改此处为当前服务器IP

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.200.71:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.200.71:2379" # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.200.71:2380,etcd-2=https://192.168.200.72:2380,etcd-3=https://192.168.200.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

最后启动etcd并设置开机启动

查看集群状态

[root@k8s-master1 ~]# 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://192.168.200.71:2379,https://192.168.200.72:2379,https://192.168.200.73:2379" endpoint health
https://192.168.200.71:2379 is healthy: successfully committed proposal: took = 11.557261ms
https://192.168.200.73:2379 is healthy: successfully committed proposal: took = 13.488713ms
https://192.168.200.72:2379 is healthy: successfully committed proposal: took = 13.398257ms

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

安装Docker

下载地址:https://download.docker.com/linux/static/stable/x86_64/docker-19.03.9.tgz
以下在所有节点操作,这里采用二进制安装,用yum安装也一样

解压二进制包

[root@k8s-master1 ~]# tar zxvf docker-19.03.9.tgz
[root@k8s-master1 ~]# mv docker/* /usr/bin

systemd管理docker

[root@k8s-master1 ~]# 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

创建配置文件

[root@k8s-master1 ~]# mkdir /etc/docker
[root@k8s-master1 ~]# cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF
registry-mirrors 阿里云镜像加速器

启动Docker设置开机启动

[root@k8s-master1 ~]# systemctl daemon-reload
[root@k8s-master1 ~]# systemctl start docker
[root@k8s-master1 ~]# systemctl enable docker

部署Master节点

生成kube-apiserver证书

自签证书颁发机构(CA)

[root@k8s-master1 ~]# cd ~/TLS/k8s/
[root@k8s-master1 k8s]# cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF
[root@k8s-master1 k8s]# cat > ca-csr.json << EOF
{
    "CN": "kubernetes",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF

生成证书:

[root@k8s-master1 k8s]# cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

[root@k8s-master1 k8s]# ls *pem
ca-key.pem  ca.pem

使用自签CA签发kube-apiserver HTTPS证书

创建证书申请文件:

[root@k8s-master1 k8s]# cd TLS/k8s
[root@k8s-master1 k8s]# cat > server-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.96.0.1",
      "127.0.0.1",
      "192.168.200.71",
      "192.168.200.72",
      "192.168.200.73",
      "192.168.200.76",
      "192.168.200.77",
      "192.168.200.78",
      "192.168.200.79",
      "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为所有Master/LB/VIP IP,一个都不能少!为了方便后期扩容可以多写几个预留的IP
生成证书:

[root@k8s-master1 k8s]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server

[root@k8s-master1 k8s]# ls server*pem
server-key.pem  server.pem

下载二进制文件

下载地址: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#v1183
打开链接你会发现里面有很多包,下载一个server包就够了,包含了Master和Worker Node二进制文件

[root@k8s-master1 ~]# wget https://storage.googleapis.com/kubernetes-release/release/v1.18.4/kubernetes-server-linux-amd64.tar.gz

解压二进制包

[root@k8s-master1 ~]# mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 
tar zxvf kubernetes-server-linux-amd64.tar.gz
[root@k8s-master1 ~]# cd kubernetes/server/bin
[root@k8s-master1 ~]# cp kube-apiserver kube-scheduler kube-controller-manager /opt/kubernetes/bin
[root@k8s-master1 ~]# cp kubectl /usr/bin/

部署kube-apiserver

创建配置文件

[root@k8s-master1 ~]# cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--etcd-servers=https://192.168.200.71:2379,https://192.168.200.72:2379,https://192.168.200.73:2379 \\
--bind-address=192.168.200.71 \\
--secure-port=6443 \\
--advertise-address=192.168.200.71 \\
--allow-privileged=true \\
--service-cluster-ip-range=10.96.0.0/24 \\
--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

--logtostderr:启用日志
---v:日志等级
--log-dir:日志目录
--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机制
--token-auth-file:bootstrap token文件
--service-node-port-range:Service nodeport类型默认分配端口范围
--kubelet-client-xxx:apiserver访问kubelet客户端证书
--tls-xxx-file:apiserver https证书
--etcd-xxxfile:连接Etcd集群证书
--audit-log-xxx:审计日志

拷贝刚才生成的证书

把刚才生成的证书拷贝到配置文件中的路径:

[root@k8s-master1 ~]# cp ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/

启用 TLS Bootstrapping 机制

TLS Bootstraping:Master apiserver启用TLS认证后,Node节点kubelet和kube-proxy要与kube-apiserver进行通信,必须使用CA签发的有效证书才可以,当Node节点很多时,这种客户端证书颁发需要大量工作,同样也会增加集群扩展复杂度。为了简化流程,Kubernetes引入了TLS bootstraping机制来自动颁发客户端证书,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。所以强烈建议在Node上使用这种方式,目前主要用于kubelet,kube-proxy还是由我们统一颁发一个证书
TLS bootstraping 工作流程:
bootstraptoken.png
创建上述配置文件中token文件:

[root@k8s-master1 ~]# cat > /opt/kubernetes/cfg/token.csv << EOF
c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF

格式:token,用户名,UID,用户组
token也可自行生成替换:

[root@k8s-master1 ~]# head -c 16 /dev/urandom | od -An -t x | tr -d ' '

systemd管理apiserver

[root@k8s-master1 ~]# 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

设置开机启动

[root@k8s-master1 ~]# systemctl daemon-reload
[root@k8s-master1 ~]# systemctl start kube-apiserver
[root@k8s-master1 ~]# systemctl enable kube-apiserver

授权kubelet-bootstrap用户允许请求证书

[root@k8s-master1 ~]# kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap

部署kube-controller-manager

创建配置文件

[root@k8s-master1 ~]# 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=10.96.0.0/24 \\
--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:通过本地非安全本地端口8080连接apiserver。
--leader-elect:当该组件启动多个时,自动选举(HA)
--cluster-signing-cert-file/--cluster-signing-key-file:自动为kubelet颁发证书的CA,与apiserver保持一致

systemd管理controller-manager

[root@k8s-master1 ~]# 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

设置开机启动

[root@k8s-master1 ~]# systemctl daemon-reload
[root@k8s-master1 ~]# systemctl start kube-controller-manager
[root@k8s-master1 ~]# systemctl enable kube-controller-manager

部署kube-scheduler

创建配置文件

[root@k8s-master1 ~]# 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:通过本地非安全本地端口8080连接apiserver
--leader-elect:当该组件启动多个时,自动选举(HA)

systemd管理scheduler

[root@k8s-master1 ~]# 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

设置开机启动

[root@k8s-master1 ~]# systemctl daemon-reload
[root@k8s-master1 ~]# systemctl start scheduler
[root@k8s-master1 ~]# systemctl enable scheduler

查看集群状态

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:

[root@k8s-master1 ~]# 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"} 

如上输出说明Master节点组件运行正常

master节点注册到集群

创建工作目录并拷贝二进制文件

[root@k8s-master1 ~]# mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 

从master节点拷贝:

[root@k8s-master1 ~]#cd kubernetes/server/bin
[root@k8s-master1 ~]#cp kubelet kube-proxy /opt/kubernetes/bin   # 本地拷贝

部署kubelet

创建配置文件

[root@k8s-master1 ~]# cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-master1 \\
--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:显示名称,集群中唯一
--network-plugin:启用CNI
--kubeconfig:空路径,会自动生成,后面用于连接apiserver
--bootstrap-kubeconfig:首次启动向apiserver申请证书
--config:配置参数文件
--cert-dir:kubelet证书生成目录
--pod-infra-container-image:管理Pod网络容器的镜像

配置参数文件

[root@k8s-master1 ~]# 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:
- 10.96.0.2
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

生成bootstrap.kubeconfig文件

[root@k8s-master1 ~]# KUBE_APISERVER="https://192.168.200.71:6443" # apiserver IP:PORT
[root@k8s-master1 ~]#TOKEN="c47ffb939f5ca36231d9e3121a252940" # 与token.csv里保持一致

# 生成 kubelet bootstrap kubeconfig 配置文件
[root@k8s-master1 ~]# kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=bootstrap.kubeconfig
[root@k8s-master1 ~]#kubectl config set-credentials "kubelet-bootstrap" \
  --token=${TOKEN} \
  --kubeconfig=bootstrap.kubeconfig
[root@k8s-master1 ~]# kubectl config set-context default \
  --cluster=kubernetes \
  --user="kubelet-bootstrap" \
  --kubeconfig=bootstrap.kubeconfig
[root@k8s-master1 ~]#kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

拷贝到配置文件路径:

[root@k8s-master1 ~]# cp bootstrap.kubeconfig /opt/kubernetes/cfg

systemd管理kubelet

[root@k8s-master1 ~]# 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

设置开机启动

[root@k8s-master1 ~]# systemctl daemon-reload
[root@k8s-master1 ~]# systemctl start kubelet
[root@k8s-master1 ~]# systemctl enable kubelet

批准kubelet证书申请并加入集群

# 查看kubelet证书请求
[root@k8s-master1 ~]# kubectl get csr
NAME                                                   AGE    SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A   6m3s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 批准申请
[root@k8s-master1 ~]# kubectl certificate approve node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A

# 查看节点
[root@k8s-master1 ~]# kubectl get node
NAME         STATUS     ROLES    AGE   VERSION
k8s-master1   NotReady   <none>   7s    v1.18.3

注:由于网络插件还没有部署,节点会没有准备就绪 NotReady

部署kube-proxy

创建配置文件

[root@k8s-master1 ~]# 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

配置参数文件

[root@k8s-master1 ~]# 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-master1
clusterCIDR: 10.96.0.0/24
EOF

生成kube-proxy.kubeconfig文件

生成kube-proxy证书:

# 切换工作目录
[root@k8s-master1 ~]# cd TLS/k8s

# 创建证书请求文件
[root@k8s-master1 ~]# 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

# 生成证书
[root@k8s-master1 ~]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy

[root@k8s-master1 ~]# ls kube-proxy*pem
kube-proxy-key.pem  kube-proxy.pem

生成kubeconfig文件:

[root@k8s-master1 ~]# KUBE_APISERVER="https://192.168.200.71:6443"

[root@k8s-master1 ~]# kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=kube-proxy.kubeconfig
[root@k8s-master1 ~]# kubectl config set-credentials kube-proxy \
  --client-certificate=./kube-proxy.pem \
  --client-key=./kube-proxy-key.pem \
  --embed-certs=true \
  --kubeconfig=kube-proxy.kubeconfig
[root@k8s-master1 ~]# kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-proxy \
  --kubeconfig=kube-proxy.kubeconfig
[root@k8s-master1 ~]# kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig

拷贝到配置文件指定路径:

[root@k8s-master1 ~]# cp kube-proxy.kubeconfig /opt/kubernetes/cfg/

systemd管理kube-proxy

[root@k8s-master1 ~]# 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

设置开机启动

[root@k8s-master1 ~]# systemctl daemon-reload
[root@k8s-master1 ~]# systemctl start kube-proxy
[root@k8s-master1 ~]# systemctl enable kube-proxy

部署CNI网络

先准备好CNI二进制文件:

下载地址:https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz
解压二进制包并移动到默认工作目录:

[root@k8s-master1 ~]# wget https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz
[root@k8s-master1 ~]# mkdir /opt/cni/bin
[root@k8s-master1 ~]# tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin

部署CNI网络:

[root@k8s-master1 ~]# wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
[root@k8s-master1 ~]# sed -i -r "s#quay.io/coreos/flannel:.*-amd64#lizhenliang/flannel:v0.12.0-amd64#g" kube-flannel.yml

默认镜像地址无法访问,修改为docker hub镜像仓库

[root@k8s-master1 ~]# kubectl apply -f kube-flannel.yml

[root@k8s-master1 ~]# kubectl get pods -n kube-system
NAME                          READY   STATUS    RESTARTS   AGE
kube-flannel-ds-amd64-2pc95   1/1     Running   0          72s

[root@k8s-master1 ~]# kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    <none>   41m   v1.18.3

部署好网络插件,Node准备就绪

授权apiserver访问kubelet

[root@k8s-master1 ~]# 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

[root@k8s-master1 ~]# kubectl apply -f apiserver-to-kubelet-rbac.yaml

master2/3节点注册

Master2 Master3与已部署的Master1所有操作一致,所以我们只需将Master1所有K8s文件拷贝过来,再修改下服务器IP和主机名启动即可

创建etcd证书目录

在Master2,3创建etcd证书目录:

mkdir -p /opt/etcd/ssl

拷贝文件(Master1操作)

拷贝Master1上所有K8s文件和etcd证书到Master2,3:

scp -r /opt/kubernetes root@192.168.200.72:/opt
scp -r /opt/cni/ root@192.168.200.72:/opt
scp -r /opt/etcd/ssl root@192.168.200.72:/opt/etcd
scp /usr/lib/systemd/system/kube* root@192.168.200.72:/usr/lib/systemd/system
scp /usr/bin/kubectl  root@192.168.200.72:/usr/bin

删除证书文件

删除kubelet证书和kubeconfig文件:

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

修改配置文件IP和主机名

修改apiserver、kubelet和kube-proxy配置文件为本地IP:

vi /opt/kubernetes/cfg/kube-apiserver.conf 
...
--bind-address=192.168.200.72 \
--advertise-address=192.168.200.72 \
...

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

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

设置开机启动

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

查看集群状态

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"}

批准kubelet证书申请

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-master1   Ready    master   10h    v1.18.4
k8s-master2   Ready    master   6h2m   v1.18.4
k8s-master3   Ready    master   6h     v1.18.4

node节点注册到集群

拷贝已部署好的master相关文件到新节点

在master节点将Worker Node涉及文件拷贝到新节点192.168.200.74/75

[root@k8s-master1 ~]# scp -r /opt/kubernetes root@192.168.200.74:/opt/

[root@k8s-master1 ~]# scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.200.74:/usr/lib/systemd/system

[root@k8s-master1 ~]# scp -r /opt/cni/ root@192.168.200.74:/opt/

[root@k8s-master1 ~]# scp /opt/kubernetes/ssl/ca.pem root@192.168.200.74:/opt/kubernetes/ssl

删除kubelet证书和kubeconfig文件

node1 node2节点执行

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

注:这几个文件是证书申请审批后自动生成的,每个Node不同,必须删除重新生成

修改主机名

[root@k8s-node1 ~]# vi /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node1

[root@k8s-node1 ~]# vi /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-node1

设置开机启动

[root@k8s-node1 ~]# systemctl daemon-reload
[root@k8s-node1 ~]# systemctl start kubelet
[root@k8s-node1 ~]# systemctl enable kubelet
[root@k8s-node1 ~]# systemctl start kube-proxy
[root@k8s-node1 ~]# systemctl enable kube-proxy

在Master上批准新Node kubelet证书申请

[root@k8s-master1 ~]# kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro   89s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

[root@k8s-master1 ~]# kubectl certificate approve node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro

查看Node状态

[root@k8s-master1 ~]# kubectl get node
NAME          STATUS   ROLES    AGE     VERSION
k8s-master1   Ready    master   10h     v1.18.4
k8s-master2   Ready    master   6h14m   v1.18.4
k8s-master3   Ready    master   6h12m   v1.18.4
k8s-node1     Ready    node     9h      v1.18.4
k8s-node2     Ready    node     10h     v1.18.4

高可用架构

本文是多master多node集群,Master节点扮演着总控中心的角色,通过不断与工作节点上的Kubelet和kube-proxy进行通信来维护整个集群的健康工作状态,如果Master节点故障,将无法使用kubectl工具或者API做任何集群管理
Master节点主要有三个服务kube-apiserver、kube-controller-manager和kube-scheduler,其中kube-controller-manager和kube-scheduler组件自身通过选择机制已经实现了高可用,所以Master高可用主要针对kube-apiserver组件,而该组件是以HTTP API提供服务,因此对他高可用与Web服务器类似,增加负载均衡器对其负载均衡即可,并且可水平扩容

部署Nginx负载均衡器

kube-apiserver高可用架构图:
nginxapiserver.png
Nginx是一个主流Web服务和反向代理服务器,这里用四层实现对apiserver实现负载均衡
Keepalived是一个主流高可用软件,基于VIP绑定实现服务器双机热备,在上述拓扑中,Keepalived主要根据Nginx运行状态判断是否需要故障转移(偏移VIP),例如当Nginx主节点挂掉,VIP会自动绑定在Nginx备节点,从而保证VIP一直可用,实现Nginx高可用

安装软件包(主/备)

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

Nginx配置文件(主/备一样)

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;
}

# 四层负载均衡,为两台Master apiserver组件提供负载均衡
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 192.168.200.71:6443;   # Master1 APISERVER IP:PORT
       server 192.168.200.72:6443;   # Master2 APISERVER IP:PORT
       server 192.168.200.73:6443;   # 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

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 ens192  # 修改为实际网卡名
    virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 
    priority 100    # 优先级,备服务器设置 90 
    advert_int 1    # 指定VRRP 心跳包通告间隔时间,默认1秒 
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    # 虚拟IP
    virtual_ipaddress { 
        192.168.200.77/24
    } 
    track_script {
        check_nginx
    } 
}
EOF

vrrp_script:指定检查nginx工作状态脚本(根据nginx状态判断是否故障转移)
virtual_ipaddress:虚拟IP(VIP)
检查nginx状态脚本:

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

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 ens192
    virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 
    priority 90
    advert_int 1
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    virtual_ipaddress { 
        192.168.200.77/24
    } 
    track_script {
        check_nginx
    } 
}
EOF

上述配置文件中检查nginx运行状态脚本:

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根据脚本返回状态码(0为工作正常,非0不正常)判断是否故障转移

设置开机启动

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

查看keepalived工作状态

[root@loadbalance-master ~]# 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: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:50:56:bb:97:92 brd ff:ff:ff:ff:ff:ff
    inet 192.168.200.76/24 brd 192.168.200.255 scope global noprefixroute ens192
       valid_lft forever preferred_lft forever
    inet 192.168.200.77/24 scope global secondary ens192
       valid_lft forever preferred_lft forever
    inet6 fe80::f178:4239:eb0c:af6b/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::34a1:73cd:4029:c490/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::21f3:e2f8:157b:4ff8/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:6d:cb:1b:14 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever

可以看到,在ens192网卡绑定了192.168.200.77 虚拟IP,说明工作正常

Nginx+Keepalived高可用测试

关闭主节点Nginx,测试VIP是否漂移到备节点服务器

在Nginx Master执行 pkill nginx
在Nginx Backup,ip addr命令查看已成功绑定VIP
[root@loadbalance-backup ~]# 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: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:50:56:bb:c6:e9 brd ff:ff:ff:ff:ff:ff
    inet 192.168.200.78/24 brd 192.168.200.255 scope global noprefixroute ens192
       valid_lft forever preferred_lft forever
    inet 192.168.200.77/24 scope global secondary ens192
       valid_lft forever preferred_lft forever
    inet6 fe80::f178:4239:eb0c:af6b/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::34a1:73cd:4029:c490/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::21f3:e2f8:157b:4ff8/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever

访问负载均衡器测试

K8s集群中任意一个节点,使用curl查看K8s版本测试,使用VIP访问:

[root@k8s-master1 ~]# curl -k https://192.168.200.77:6443/version
{
  "major": "1",
  "minor": "18",
  "gitVersion": "v1.18.4",
  "gitCommit": "c96aede7b5205121079932896c4ad89bb93260af",
  "gitTreeState": "clean",
  "buildDate": "2020-06-17T11:33:59Z",
  "goVersion": "go1.13.9",
  "compiler": "gc",
  "platform": "linux/amd64"
}

可以正确获取到K8s版本信息,说明负载均衡器搭建正常。该请求数据流程:curl -> vip(nginx) -> apiserver

通过查看Nginx日志也可以看到转发apiserver IP:

[root@loadbalance-master ~]# tail /var/log/nginx/k8s-access.log -f
192.168.200.75 192.168.200.73:6443 - [27/Jun/2020:13:55:28 +0800] 200 1179
192.168.200.75 192.168.200.72:6443 - [27/Jun/2020:13:55:28 +0800] 200 1179
192.168.200.75 192.168.200.71:6443 - [27/Jun/2020:13:55:28 +0800] 200 1180
192.168.200.75 192.168.200.71:6443 - [27/Jun/2020:13:55:28 +0800] 200 1179
192.168.200.73 192.168.200.71:6443 - [27/Jun/2020:13:55:28 +0800] 200 1180
192.168.200.73 192.168.200.72:6443 - [27/Jun/2020:13:55:28 +0800] 200 1181
192.168.200.73 192.168.200.72:6443 - [27/Jun/2020:13:55:28 +0800] 200 1180
192.168.200.73 192.168.200.73:6443 - [27/Jun/2020:13:55:28 +0800] 200 1182
192.168.200.73 192.168.200.72:6443 - [27/Jun/2020:13:55:28 +0800] 200 1181
192.168.200.73 192.168.200.73:6443 - [27/Jun/2020:13:55:28 +0800] 200 1182

修改所有节点连接LB VIP

虽然我们增加了Master2 Master3和负载均衡器,目前所有的Node组件连接都还是Master1,如果不改为连接VIP走负载均衡器,那么Master还是单点故障
因此接下来就是要改所有节点组件配置文件,由原来192.168.200.77修改为192.168.200.77(VIP):

#所有节点执行
sed -i 's#192.168.200.71:6443#192.168.200.77:6443#' /opt/kubernetes/cfg/*
systemctl restart kubelet
systemctl restart kube-proxy

#检查节点状态
[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS   ROLES    AGE   VERSION
k8s-master1   Ready    master   22h   v1.18.4
k8s-master2   Ready    master   17h   v1.18.4
k8s-master3   Ready    master   17h   v1.18.4
k8s-node1     Ready    node     20h   v1.18.4
k8s-node2     Ready    node     21h   v1.18.4