k8s安装

2021/4/15 10:56:06

本文主要是介绍k8s安装,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!

10:23:02

 

 

 

 

《部署一套完整的企业级K8s集群》

v1.20,二进制方式

 

作者信息

李振良(阿良),微信:xyz12366699

DevOps实战学院

http://www.aliangedu.cn

说明

该文档有导航窗格,方便阅读,如果左侧没有显示,请检查word是否启用。

转载请注明作者,拒绝不道德行为!

最后更新时间

2021-04-06

 

 

 

 

 

一、前置知识点

1.1 生产环境部署K8s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。

  • 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。

小结: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。

1.2 准备环境

服务器要求:

  • 建议最小硬件配置:2核CPU、2G内存、30G硬盘
  • 服务器最好可以访问外网,会有从网上拉取镜像需求,如果服务器不能上网,需要提前下载对应镜像并导入节点

软件环境:

软件

版本

操作系统

CentOS7.x_x64 (mini)

容器引擎

Docker CE 19

Kubernetes

Kubernetes v1.20

服务器整体规划:

角色

IP

组件

k8s-master1

192.168.31.71

kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker,etcd,

nginx,keepalived

k8s-master2

192.168.31.74

kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker,

nginx,keepalived

k8s-node1

192.168.31.72

kubelet,kube-proxy,docker,etcd

k8s-node2

192.168.31.73

kubelet,kube-proxy,docker,etcd

负载均衡器IP

192.168.31.88 (VIP)

 

 

须知:考虑到有些朋友电脑配置较低,一次性开四台机器会跑不动,所以搭建这套K8s高可用集群分两部分实施,先部署一套单Master架构(3台),再扩容为多Master架构(4台或6台),顺便再熟悉下Master扩容流程。

单Master架构图:

 

 

单Master服务器规划:

角色

IP

组件

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

1.3 操作系统初始化配置

 

# 关闭防火墙 

systemctl stop firewalld 

systemctl disable firewalld 

 

# 关闭selinux 

sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久 

setenforce 0  # 临时 

 

# 关闭swap 

swapoff -a  # 临时 

sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久 

 

# 根据规划设置主机名 

hostnamectl set-hostname <hostname> 

 

# 在master添加hosts 

cat >> /etc/hosts << EOF 

192.168.31.71 k8s-master1 

192.168.31.72 k8s-node1 

192.168.31.73 k8s-node2 

EOF 

 

# 将桥接的IPv4流量传递到iptables的链 

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 

 

# 时间同步 

yum install ntpdate -y 

ntpdate time.windows.com

 

二、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-1

192.168.31.71

etcd-2

192.168.31.72

etcd-3

192.168.31.73

注:为了节省机器,这里与K8s节点机器复用。也可以独立于k8s集群之外部署,只要apiserver能连接到就行。

2.1 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。

找任意一台服务器操作,这里用Master节点。

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证书

1. 自签证书颁发机构(CA)

创建工作目录:

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



cd ~/TLS/etcd

自签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

生成证书:

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

会生成ca.pem和ca-key.pem文件。

2. 使用自签CA签发Etcd HTTPS证书

创建证书申请文件:

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:

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

会生成server.pem和server-key.pem文件。

2.3 从Github下载二进制文件

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

2.4 部署Etcd集群

以下在节点1上操作,为简化操作,待会将节点1生成的所有文件拷贝到节点2和节点3.

1. 创建工作目录并解压二进制包

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. 创建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: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_PEERURLS: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_INITIALCLUSTER_TOKEN:集群Token
  • ETCD_INITIALCLUSTER_STATE:加入集群的当前状态,new是新集群,existing表示加入已有集群

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:

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

5. 启动并设置开机启动

systemctl daemon-reload

systemctl start etcd

systemctl enable etcd

6. 将上面节点1所有生成的文件拷贝到节点2和节点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/

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

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://192.168.31.71:2380"   # 修改此处为当前服务器IP

ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379" # 修改此处为当前服务器IP



#[Clustering]

ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380" # 修改此处为当前服务器IP

ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379" # 修改此处为当前服务器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"

最后启动etcd并设置开机启动,同上。

7. 查看集群状态

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 --write-out=table



+----------------------------+--------+-------------+-------+

|          ENDPOINT    | HEALTH |    TOOK     | ERROR |

+----------------------------+--------+-------------+-------+

| https://192.168.31.71:2379 |   true | 10.301506ms |    |

| https://192.168.31.73:2379 |   true | 12.87467ms |     |

| https://192.168.31.72:2379 |   true | 13.225954ms |    |

+----------------------------+--------+-------------+-------+

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

三、安装Docker

这里使用Docker作为容器引擎,也可以换成别的,例如containerd

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。

3.1 解压二进制包

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 创建配置文件

mkdir /etc/docker

cat > /etc/docker/daemon.json << EOF

{

  "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]

}

EOF
  • registry-mirrors 阿里云镜像加速器

3.4 启动并设置开机启动

systemctl daemon-reload

systemctl start docker

systemctl enable docker

四、部署Master Node

如果你在学习中遇到问题或者文档有误可联系阿良~ 微信: xyz12366699

4.1 生成kube-apiserver证书

1. 自签证书颁发机构(CA)

cd ~/TLS/k8s

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

生成证书:

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

会生成ca.pem和ca-key.pem文件。

2. 使用自签CA签发kube-apiserver HTTPS证书

创建证书申请文件:

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",

      "192.168.31.88",

      "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:

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

会生成server.pem和server-key.pem文件。

4.2 从Github下载二进制文件

下载地址: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.20.md

注: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。

4.3 解压二进制包

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. 创建配置文件

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 \\

--service-account-issuer=api \\

--service-account-signing-key-file=/opt/kubernetes/ssl/server-key.pem \\

--etcd-cafile=/opt/etcd/ssl/ca.pem \\

--etcd-certfile=/opt/etcd/ssl/server.pem \\

--etcd-keyfile=/opt/etcd/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:上面两个\ \ 第一个是转义符,第二个是换行符,使用转义符是为了使用EOF保留换行符。

  • --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
  • 1.20版本必须加的参数:--service-account-issuer,--service-account-signing-key-file
  • --etcd-xxxfile:连接Etcd集群证书
  • --audit-log-xxx:审计日志
  • 启动聚合层相关配置:--requestheader-client-ca-file,--proxy-client-cert-file,--proxy-client-key-file,--requestheader-allowed-names,--requestheader-extra-headers-prefix,--requestheader-group-headers,--requestheader-username-headers,--enable-aggregator-routing

2. 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:

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

3. 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:

 

 

创建上述配置文件中token文件:

cat > /opt/kubernetes/cfg/token.csv << EOF

c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"

EOF

格式:token,用户名,UID,用户组

token也可自行生成替换:

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. 启动并设置开机启动

systemctl daemon-reload

systemctl start kube-apiserver 

systemctl enable kube-apiserver

4.5 部署kube-controller-manager

1. 创建配置文件

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 \\

--kubeconfig=/opt/kubernetes/cfg/kube-controller-manager.kubeconfig \\

--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 \\

--cluster-signing-duration=87600h0m0s"

EOF
  • --kubeconfig:连接apiserver配置文件
  • --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

2. 生成kubeconfig文件

生成kube-controller-manager证书:

# 切换工作目录

cd ~/TLS/k8s



# 创建证书请求文件

cat > kube-controller-manager-csr.json << EOF

{

  "CN": "system:kube-controller-manager",

  "hosts": [],

  "key": {

    "algo": "rsa",

    "size": 2048

  },

  "names": [

    {

      "C": "CN",

      "L": "BeiJing", 

      "ST": "BeiJing",

      "O": "system:masters",

      "OU": "System"

    }

  ]

}

EOF



# 生成证书

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

生成kubeconfig文件(以下是shell命令,直接在终端执行):

KUBE_CONFIG="/opt/kubernetes/cfg/kube-controller-manager.kubeconfig"

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_CONFIG}

kubectl config set-credentials kube-controller-manager \

  --client-certificate=./kube-controller-manager.pem \

  --client-key=./kube-controller-manager-key.pem \

  --embed-certs=true \

  --kubeconfig=${KUBE_CONFIG}

kubectl config set-context default \

  --cluster=kubernetes \

  --user=kube-controller-manager \

  --kubeconfig=${KUBE_CONFIG}

kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

3. 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

4. 启动并设置开机启动

systemctl daemon-reload

systemctl start kube-controller-manager

systemctl enable kube-controller-manager

4.6 部署kube-scheduler

1. 创建配置文件

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

KUBE_SCHEDULER_OPTS="--logtostderr=false \\

--v=2 \\

--log-dir=/opt/kubernetes/logs \\

--leader-elect \\

--kubeconfig=/opt/kubernetes/cfg/kube-scheduler.kubeconfig \\

--bind-address=127.0.0.1"

EOF
  • --kubeconfig:连接apiserver配置文件
  • --leader-elect:当该组件启动多个时,自动选举(HA)

2. 生成kubeconfig文件

生成kube-scheduler证书:

# 切换工作目录

cd ~/TLS/k8s



# 创建证书请求文件

cat > kube-scheduler-csr.json << EOF

{

  "CN": "system:kube-scheduler",

  "hosts": [],

  "key": {

    "algo": "rsa",

    "size": 2048

  },

  "names": [

    {

      "C": "CN",

      "L": "BeiJing",

      "ST": "BeiJing",

      "O": "system:masters",

      "OU": "System"

    }

  ]

}

EOF



# 生成证书

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

生成kubeconfig文件(以下是shell命令,直接在终端执行):

KUBE_CONFIG="/opt/kubernetes/cfg/kube-scheduler.kubeconfig"

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_CONFIG}

kubectl config set-credentials kube-scheduler \

  --client-certificate=./kube-scheduler.pem \

  --client-key=./kube-scheduler-key.pem \

  --embed-certs=true \

  --kubeconfig=${KUBE_CONFIG}

kubectl config set-context default \

  --cluster=kubernetes \

  --user=kube-scheduler \

  --kubeconfig=${KUBE_CONFIG}

kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

3. 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

4. 启动并设置开机启动

systemctl daemon-reload

systemctl start kube-scheduler

systemctl enable kube-scheduler

5. 查看集群状态

生成kubectl连接集群的证书:

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

生成kubeconfig文件:

mkdir /root/.kube

KUBE_CONFIG="/root/.kube/config"

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_CONFIG}

kubectl config set-credentials cluster-admin \

  --client-certificate=./admin.pem \

  --client-key=./admin-key.pem \

  --embed-certs=true \

  --kubeconfig=${KUBE_CONFIG}

kubectl config set-context default \

  --cluster=kubernetes \

  --user=cluster-admin \

  --kubeconfig=${KUBE_CONFIG}

kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

通过kubectl工具查看当前集群组件状态:

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"}  

如上输出说明Master节点组件运行正常。

6. 授权kubelet-bootstrap用户允许请求证书

kubectl create clusterrolebinding kubelet-bootstrap \

--clusterrole=system:node-bootstrapper \

--user=kubelet-bootstrap

五、部署Worker Node

如果你在学习中遇到问题或者文档有误可联系阿良~ 微信: xyz12366699

下面还是在Master Node上操作,即同时作为Worker Node

5.1 创建工作目录并拷贝二进制文件

在所有worker node创建工作目录:

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

从master节点拷贝:

cd kubernetes/server/bin

cp kubelet kube-proxy /opt/kubernetes/bin   # 本地拷贝

5.2 部署kubelet

1. 创建配置文件

cat > /opt/kubernetes/cfg/kubelet.conf << EOF

KUBELET_OPTS="--logtostderr=false \\

--v=2 \\

--log-dir=/opt/kubernetes/logs \\

--hostname-override=k8s-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

2. 配置参数文件

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kubelet初次加入集群引导kubeconfig文件

KUBE_CONFIG="/opt/kubernetes/cfg/bootstrap.kubeconfig"

KUBE_APISERVER="https://192.168.31.71:6443" # apiserver IP:PORT

TOKEN="c47ffb939f5ca36231d9e3121a252940" # 与token.csv里保持一致



# 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=${KUBE_CONFIG}

kubectl config set-credentials "kubelet-bootstrap" \

  --token=${TOKEN} \

  --kubeconfig=${KUBE_CONFIG}

kubectl config set-context default \

  --cluster=kubernetes \

  --user="kubelet-bootstrap" \

  --kubeconfig=${KUBE_CONFIG}

kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

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. 启动并设置开机启动

systemctl daemon-reload

systemctl start kubelet

systemctl enable kubelet

5.3 批准kubelet证书申请并加入集群

# 查看kubelet证书请求

kubectl get csr

NAME                                                   AGE    SIGNERNAME                                    REQUESTOR           CONDITION

node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A   6m3s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending



# 批准申请

kubectl certificate approve node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A



# 查看节点

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

5.4 部署kube-proxy

1. 创建配置文件

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. 配置参数文件

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-master1

clusterCIDR: 10.0.0.0/24

EOF

3. 生成kube-proxy.kubeconfig文件

生成kube-proxy证书:

# 切换工作目录

cd ~/TLS/k8s



# 创建证书请求文件

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



# 生成证书

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
生成kubeconfig文件:
KUBE_CONFIG="/opt/kubernetes/cfg/kube-proxy.kubeconfig"

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_CONFIG}

kubectl config set-credentials kube-proxy \

  --client-certificate=./kube-proxy.pem \

  --client-key=./kube-proxy-key.pem \

  --embed-certs=true \

  --kubeconfig=${KUBE_CONFIG}

kubectl config set-context default \

  --cluster=kubernetes \

  --user=kube-proxy \

  --kubeconfig=${KUBE_CONFIG}

kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

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. 启动并设置开机启动

systemctl daemon-reload

systemctl start kube-proxy

systemctl enable kube-proxy

5.5 部署网络组件

Calico是一个纯三层的数据中心网络方案,是目前Kubernetes主流的网络方案。

部署Calico:

kubectl apply -f calico.yaml

kubectl get pods -n kube-system

等Calico Pod都Running,节点也会准备就绪:

kubectl get node

NAME         STATUS   ROLES    AGE   VERSION

k8s-master   Ready    <none>   37m   v1.20.4

5.6 授权apiserver访问kubelet

应用场景:例如kubectl logs

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 新增加Worker Node

1. 拷贝已部署好的Node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192.168.31.72/73

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

2. 删除kubelet证书和kubeconfig文件

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

3. 修改主机名

vi /opt/kubernetes/cfg/kubelet.conf

--hostname-override=k8s-node1



vi /opt/kubernetes/cfg/kube-proxy-config.yml

hostnameOverride: k8s-node1

4. 启动并设置开机启动

systemctl daemon-reload

systemctl start kubelet kube-proxy

systemctl enable kubelet kube-proxy

5. 在Master上批准新Node kubelet证书申请

# 查看证书请求

kubectl get csr

NAME           AGE   SIGNERNAME                    REQUESTOR           CONDITION

node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro   89s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending



# 授权请求

kubectl certificate approve node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro

6. 查看Node状态

kubectl get node

NAME       STATUS   ROLES    AGE     VERSION

k8s-master1   Ready    <none>   47m     v1.20.4

k8s-node1    Ready    <none>   6m49s   v1.20.4

Node2(192.168.31.73 )节点同上。记得修改主机名!

六、部署Dashboard和CoreDNS

6.1 部署Dashboard

kubectl apply -f kubernetes-dashboard.yaml
# 查看部署
kubectl get pods,svc -n kubernetes-dashboard

访问地址:https://NodeIP:30001

创建service account并绑定默认cluster-admin管理员集群角色:

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}')

使用输出的token登录Dashboard。

 

 

 

 

6.2 部署CoreDNS

CoreDNS用于集群内部Service名称解析。

kubectl apply -f coredns.yaml 

 

kubectl get pods -n kube-system  

NAME                          READY   STATUS    RESTARTS   AGE 

coredns-5ffbfd976d-j6shb      1/1     Running   0          32s

DNS解析测试:

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

解析没问题。

至此一个单Master集群就搭建完成了!这个环境就足以满足学习实验了,如果你的服务器配置较高,可继续扩容多Master集群!

七、扩容多Master(高可用架构)

Kubernetes作为容器集群系统,通过健康检查+重启策略实现了Pod故障自我修复能力,通过调度算法实现将Pod分布式部署,并保持预期副本数,根据Node失效状态自动在其他Node拉起Pod,实现了应用层的高可用性。

针对Kubernetes集群,高可用性还应包含以下两个层面的考虑:Etcd数据库的高可用性和Kubernetes Master组件的高可用性。 而Etcd我们已经采用3个节点组建集群实现高可用,本节将对Master节点高可用进行说明和实施。

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。

多Master架构图:

 

 

7.1 部署Master2 Node

现在需要再增加一台新服务器,作为Master2 Node,IP是192.168.31.74。

为了节省资源你也可以将之前部署好的Worker Node1复用为Master2 Node角色(即部署Master组件)

Master2 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。

1. 安装Docker

scp /usr/bin/docker* root@192.168.31.74:/usr/bin

scp /usr/bin/runc root@192.168.31.74:/usr/bin

scp /usr/bin/containerd* root@192.168.31.74:/usr/bin

scp /usr/lib/systemd/system/docker.service root@192.168.31.74:/usr/lib/systemd/system

scp -r /etc/docker root@192.168.31.74:/etc



# 在Master2启动Docker

systemctl daemon-reload

systemctl start docker

systemctl enable docker

2. 创建etcd证书目录

在Master2创建etcd证书目录:

mkdir -p /opt/etcd/ssl

3. 拷贝文件(Master1操作)

拷贝Master1上所有K8s文件和etcd证书到Master2:

scp -r /opt/kubernetes 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

scp -r ~/.kube root@192.168.31.74:~

4. 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*

5. 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=192.168.31.74 \

--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

6. 启动设置开机启动

systemctl daemon-reload

systemctl start kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy

systemctl enable kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy

7. 查看集群状态

# 修改连接master为本机IP

vi ~/.kube/config

...

server: https://192.168.31.74:6443



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"}

8. 批准kubelet证书申请

# 查看证书请求

kubectl get csr

NAME                      AGE          SIGNERNAME          REQUESTOR           CONDITION

node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU   85m   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 授权请求

kubectl certificate approve node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU



# 查看Node

kubectl get node

NAME        STATUS   ROLES    AGE   VERSION

k8s-master1    Ready    <none>   34h   v1.20.4

k8s-master2    Ready    <none>   2m   v1.20.4

k8s-node1     Ready    <none>   33h   v1.20.4

k8s-node2     Ready    <none>   33h   v1.20.4

如果你在学习中遇到问题或者文档有误可联系阿良~ 微信: xyz12366699

7.2 部署Nginx+Keepalived高可用负载均衡器

kube-apiserver高可用架构图:

 

 

  • 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(漂移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。

注1:为了节省机器,这里与K8s Master节点机器复用。也可以独立于k8s集群之外部署,只要nginx与apiserver能通信就行。

注2:如果你是在公有云上,一般都不支持keepalived,那么你可以直接用它们的负载均衡器产品,直接负载均衡多台Master kube-apiserver,架构与上面一样。

在两台Master节点操作。

1. 安装软件包(主/备)

 yum install epel-release -y

 yum install nginx keepalived -y

2. 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 192.168.31.71:6443;   # Master1 APISERVER IP:PORT

       server 192.168.31.72:6443;   # Master2 APISERVER IP:PORT

    }

    

    server {

       listen 16443; # 由于nginx与master节点复用,这个监听端口不能是6443,否则会冲突

       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  # 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 { 

        192.168.31.88/24

    } 

    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)

准备上述配置文件中检查nginx运行状态的脚本:

cat > /etc/keepalived/check_nginx.sh  << "EOF"

#!/bin/bash

count=$(ss -antp |grep 16443 |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 { 

        192.168.31.88/24

    } 

    track_script {

        check_nginx

    } 

}

EOF

准备上述配置文件中检查nginx运行状态的脚本:

cat > /etc/keepalived/check_nginx.sh  << "EOF"

#!/bin/bash

count=$(ss -antp |grep 16443 |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。

5. 启动并设置开机启动

systemctl daemon-reload

systemctl start nginx keepalived

systemctl enable nginx keepalived

6. 查看keepalived工作状态

ip addr

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

可以看到,在ens33网卡绑定了192.168.31.88 虚拟IP,说明工作正常。

7. 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。

8. 访问负载均衡器测试

找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:

curl -k https://192.168.31.88:16443/version

{

  "major": "1",

  "minor": "20",

  "gitVersion": "v1.20.4",

  "gitCommit": "e87da0bd6e03ec3fea7933c4b5263d151aafd07c",

  "gitTreeState": "clean",

  "buildDate": "2021-02-18T16:03:00Z",

  "goVersion": "go1.15.8",

  "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:

tail /var/log/nginx/k8s-access.log -f

192.168.31.71 192.168.31.71:6443 - [02/Apr/2021:19:17:57 +0800] 200 423

192.168.31.71 192.168.31.72:6443 - [02/Apr/2021:19:18:50 +0800] 200 423

到此还没结束,还有下面最关键的一步。

7.3 修改所有Worker Node连接LB VIP

试想下,虽然我们增加了Master2 Node和负载均衡器,但是我们是从单Master架构扩容的,也就是说目前所有的Worker Node组件连接都还是Master1 Node,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Worker Node(kubectl get node命令查看到的节点)组件配置文件,由原来192.168.31.71修改为192.168.31.88(VIP)。

在所有Worker Node执行:

sed -i 's#192.168.31.71:6443#192.168.31.88:16443#' /opt/kubernetes/cfg/*

systemctl restart kubelet kube-proxy

检查节点状态:

kubectl get node 

NAME         STATUS   ROLES    AGE   VERSION 

k8s-master1   Ready    <none>   32d   v1.20.4 

k8s-master2   Ready    <none>   10m   v1.20.4 

k8s-node1    Ready    <none>   31d   v1.20.4 

k8s-node2    Ready    <none>   31d   v1.20.4

至此,一套完整的 Kubernetes 高可用集群就部署完成了!

 

 

 



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