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二进制搭建k8s高可用集群

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前言:

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一、环境准备1.1、部署k8s的两种方式

1)方式一:kubeadm部署

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。

2)方式二:二进制软件包

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

3)两种方式对比

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

1.2.1、服务器要求

1)建议最小硬件配置:2核CPU、2G内存、30G硬盘

2)服务器最好可以访问外网,会有从网上拉取镜像的需求,如果服务器不能上网,需要提前下载对应镜像并导入节点

1.2.2、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

1.2.3、服务器整体规划

角色

IP

组件

k8s-master1

10.0.153.109

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

k8s-master2

10.0.153.110

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

k8s-node1

10.0.153.112

kubelet,kube-proxy,docker,etcd

k8s-node2

10.0.153.108

kubelet,kube-proxy,docker,etcd

负载均衡器IP

10.0.153.88

单master架构

单节点架构图

1.2.4、操作系统初始化配置

# 1、关闭防火墙 systemctl stop firewalld systemctl disable firewalld  # 2、关闭selinux sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久 setenforce 0  # 临时  # 3、关闭swap swapoff -a  # 临时 sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久  # 4、根据规划设置主机名 hostnamectl set-hostname <hostname>  # 5、在master添加hosts cat >> /etc/hosts << EOF 10.0.153.109 master0110.0.153.110 master0210.0.153.112 node0110.0.153.108 node02EOF # 6、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  # 7、时间同步 yum install ntpdate -y ntpdate time.windows.com
1.3、证书说明

证书说明

二、部署Etcd集群

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

# 下载软件包(有下载失败的可以私信我发包)mkdir cfssl && cd cfssl/wget    +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64mv cfssl_linux-amd64 /usr/local/bin/cfsslmv cfssljson_linux-amd64 /usr/local/bin/cfssljsonmv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo
2.2、生成Etcd证书

2.2.1、自签证书颁发机构(CA)

# 1、创建工作目录mkdir -p ~/TLS/{etcd,k8s} && cd ~/TLS/etcd# 2、自签CAcat > ca-config.json << EOF{  "signing": {    "default": {      "expiry": "87600h"    },    "profiles": {      "www": {         "expiry": "87600h",         "usages": [            "signing",            "key encipherment",            "server auth",            "client auth"        ]      }    }  }}EOFcat > ca-csr.json << EOF{    "CN": "etcd CA",    "key": {        "algo": "rsa",        "size": 2048    },    "names": [        {            "C": "CN",            "L": "Beijing",            "ST": "Beijing"        }    ]}EOF# 3、生成证书:会生成ca.pem和ca-key.pem文件cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
2.2.2、使用自签CA签发Etcd Https证书
# 创建证书请求文件cat > server-csr.json << EOF{    "CN": "etcd",    "hosts": [    "10.0.153.109",    "10.0.153.110",    "10.0.153.111",      "10.0.153.112",    "10.0.153.88",    "10.0.153.108"    ],    "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,会生成server.pem和server-key.pem文件cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server
2.3、部署Etcd集群

1)下载etcd二进制文件

地址:

2)创建工作目录并解压二进制包

mkdir /opt/etcd/{bin,cfg,ssl} -ptar zxvf etcd-v3.4.9-linux-amd64.tar.gzmv etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

3)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/"ETCD_LISTEN_PEER_URLS=";ETCD_LISTEN_CLIENT_URLS=";#[Clustering]ETCD_INITIAL_ADVERTISE_PEER_URLS=";ETCD_ADVERTISE_CLIENT_URLS=";ETCD_INITIAL_CLUSTER="etcd-1=;ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"ETCD_INITIAL_CLUSTER_STATE="new"EOF

配置文件说明

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

4)systemd管理etcd

cat > /usr/lib/systemd/system/etcd.service << EOF[Unit]Description=Etcd ServerAfter=network.targetAfter=network-online.targetWants=network-online.target[Service]Type=notifyEnvironmentFile=/opt/etcd/cfg/etcd.confExecStart=/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=zapRestart=on-failureLimitNOFILE=65536[Install]WantedBy=multi-user.targetEOF

5)拷贝生成的证书至指定位置

# 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/

6)启动并设置开机启动

systemctl daemon-reloadsystemctl start etcdsystemctl enable etcd

注意:此时启动一台etcd会显示hang住,这是因为其他两个节点并没有启动,可以查看日志/var/log/messages

etcd 夯住的日志

7)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@10.0.153.112:/opt/scp /usr/lib/systemd/system/etcd.service root@10.0.153.112:/usr/lib/systemd/system/scp -r /opt/etcd/ root@10.0.153.108:/opt/scp /usr/lib/systemd/system/etcd.service root@10.0.153.108:/usr/lib/systemd/system/

8)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

vim /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-3ETCD_DATA_DIR="/var/lib/etcd/default.etcd"ETCD_LISTEN_PEER_URLS=";   # 修改此处为当前服务器IPETCD_LISTEN_CLIENT_URLS="; # 修改此处为当前服务器IP#[Clustering]ETCD_INITIAL_ADVERTISE_PEER_URLS="; # 修改此处为当前服务器IPETCD_ADVERTISE_CLIENT_URLS="; # 修改此处为当前服务器IPETCD_INITIAL_CLUSTER="etcd-1=;ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"ETCD_INITIAL_CLUSTER_STATE="new"

9)启动etcd并设置开机启动

systemctl daemon-reloadsystemctl start etcdsystemctl enable etcd

10)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="; endpoint health --write-out=table# 显示结果如下,说明部署成功+---------------------------+--------+-------------+-------+|         ENDPOINT          | HEALTH |    TOOK     | ERROR |+---------------------------+--------+-------------+-------+|  |   true | 10.008247ms |       ||  |   true | 17.968196ms |       ||  |   true | 17.918646ms |       |+---------------------------+--------+-------------+-------+
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:

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。

1)解压二进制软件包

tar zxvf docker-19.03.9.tgzmv docker/* /usr/bindocker version

2)systemd管理docker

cat > /usr/lib/systemd/system/docker.service << EOF[Unit]Description=Docker Application Container EngineDocumentation= firewalld.serviceWants=network-online.target[Service]Type=notifyExecStart=/usr/bin/dockerdExecReload=/bin/kill -s HUP $MAINPIDLimitNOFILE=infinityLimitNPROC=infinityLimitCORE=infinityTimeoutStartSec=0Delegate=yesKillMode=processRestart=on-failureStartLimitBurst=3StartLimitInterval=60s[Install]WantedBy=multi-user.targetEOF

3)创建配置文件

mkdir /etc/dockercat > /etc/docker/daemon.json << EOF{  "registry-mirrors": [";]}EOF

4)启动并设置开机启动

systemctl daemon-reloadsystemctl start dockersystemctl enable docker
四、部署Master Node

4.1、部署kube-apiserver

4.1.1、自签证书签发机构(CA)

cd ~/TLS/k8scat > ca-config.json << EOF{  "signing": {    "default": {      "expiry": "87600h"    },    "profiles": {      "kubernetes": {         "expiry": "87600h",         "usages": [            "signing",            "key encipherment",            "server auth",            "client auth"        ]      }    }  }}EOFcat > 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:生成ca.pem和ca-key.pem文件ca
4.1.2、使用自签CA签发kube-apiserver HTTPS证书
# 创建证书请求文件cat > server-csr.json << EOF{    "CN": "kubernetes",    "hosts": [      "10.0.0.1",      "127.0.0.1",      "10.0.153.109",      "10.0.153.110",      "10.0.153.111",      "10.0.153.112",      "10.0.153.108",      "10.0.153.115",      "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

注意: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,生成server.pem和server-key.pemcfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server

4.1.3、部署kube-apiserver步骤

下载地址:

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

Server Binaries

filename

sha512 hash

kubernetes-server-linux-amd64.tar.gz

e7fe2125526fe617fe3beb4b8bc46fbb8dd1f3422fcd5913f70feaeec5765d1db8abea867c4f8d3c406b1d40c789c150b41c

1)下载并解压二进制软件包

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

2)创建配置文件

cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOFKUBE_APISERVER_OPTS="--logtostderr=false \\--v=2 \\--log-dir=/opt/kubernetes/logs \\--etcd-servers= \\--bind-address=10.0.153.109 \\--secure-port=6443 \\--advertise-address=10.0.153.109 \\--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

参数说明

--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

3)拷贝生成的证书

# 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/

4)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:

5)创建token文件

# 格式:token,用户名,UID,用户组cat > /opt/kubernetes/cfg/token.csv << EOFf18f49462c7d24a68aeeb5c75b093943,kubelet-bootstrap,10001,"system:node-bootstrapper"EOF

token也可自行生成替换:

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

6)systemd管理apiserver

cat > /usr/lib/systemd/system/kube-apiserver.service << EOF[Unit]Description=Kubernetes API ServerDocumentation=[Service]EnvironmentFile=/opt/kubernetes/cfg/kube-apiserver.confExecStart=/opt/kubernetes/bin/kube-apiserver \$KUBE_APISERVER_OPTSRestart=on-failure[Install]WantedBy=multi-user.targetEOF

7)启动并设置开机启动

systemctl daemon-reloadsystemctl start kube-apiserver systemctl enable kube-apiserver
4.2、部署kube-controller-manager

1)创建配置文件

cat > /opt/kubernetes/cfg/kube-controller-manager.conf << EOFKUBE_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

配置说明

--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=";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 ManagerDocumentation=[Service]EnvironmentFile=/opt/kubernetes/cfg/kube-controller-manager.confExecStart=/opt/kubernetes/bin/kube-controller-manager \$KUBE_CONTROLLER_MANAGER_OPTSRestart=on-failure[Install]WantedBy=multi-user.targetEOF

4)启动并设置开机启动

systemctl daemon-reloadsystemctl start kube-controller-managersystemctl enable kube-controller-manager
4.3、部署kube-scheduler

1)创建配置文件

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

参数说明:

--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=";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 SchedulerDocumentation=[Service]EnvironmentFile=/opt/kubernetes/cfg/kube-scheduler.confExecStart=/opt/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTSRestart=on-failure[Install]WantedBy=multi-user.targetEOF

4)启动并设置开机启动

systemctl daemon-reloadsystemctl start kube-schedulersystemctl 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"    }  ]}EOFcfssl 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/.kubeKUBE_CONFIG="/root/.kube/config"KUBE_APISERVER=";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# 如下输出说明Master节点组件运行正常Warning: v1 ComponentStatus is deprecated in v1.19+NAME                 STATUS    MESSAGE             ERRORscheduler            Healthy   ok                  controller-manager   Healthy   ok                  etcd-2               Healthy   {"health":"true"}   etcd-1               Healthy   {"health":"true"}   etcd-0               Healthy   {"health":"true"}

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

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(master已创建,新加入节点需要创建)mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}# 从解压的k8s server压缩包中拷贝文件cd /root/soft/kubernetes/server/bincp kubelet kube-proxy /opt/kubernetes/bin
5.2、部署kubelet

1)创建配置文件

cat > /opt/kubernetes/cfg/kubelet.conf << EOFKUBELET_OPTS="--logtostderr=false \\--v=2 \\--log-dir=/opt/kubernetes/logs \\--hostname-override=master01 \\--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="registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0"EOF

参数说明:

--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 << EOFkind: KubeletConfigurationapiVersion: kubelet.config.k8s.io/v1beta1address: 0.0.0.0port: 10250readOnlyPort: 10255cgroupDriver: cgroupfsclusterDNS:- 10.0.0.2clusterDomain: cluster.local failSwapOn: falseauthentication:  anonymous:    enabled: false  webhook:    cacheTTL: 2m0s    enabled: true  x509:    clientCAFile: /opt/kubernetes/ssl/ca.pem authorization:  mode: Webhook  webhook:    cacheAuthorizedTTL: 5m0s    cacheUnauthorizedTTL: 30sevictionHard:  imagefs.available: 15%  memory.available: 100Mi  nodefs.available: 10%  nodefs.inodesFree: 5%maxOpenFiles: 1000000maxPods: 110EOF

3)生成kubelet初次加入集群引导kubeconfig文件

KUBE_CONFIG="/opt/kubernetes/cfg/bootstrap.kubeconfig"KUBE_APISERVER="; # apiserver IP:PORTTOKEN="f18f49462c7d24a68aeeb5c75b093943" # 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 KubeletAfter=docker.service[Service]EnvironmentFile=/opt/kubernetes/cfg/kubelet.confExecStart=/opt/kubernetes/bin/kubelet \$KUBELET_OPTSRestart=on-failureLimitNOFILE=65536[Install]WantedBy=multi-user.targetEOF

5)启动并设置开机启动

systemctl daemon-reloadsystemctl start kubeletsystemctl enable kubelet

6)批准kubelet证书申请并加入集群

# 查看kubelet证书请求kubectl get csrNAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITIONnode-csr-5dm283moOkPBkGWiUacHXSievGGVmZkXFynXbLL0PG0   31m   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending# 批准申请kubectl certificate approve node-csr-5dm283moOkPBkGWiUacHXSievGGVmZkXFynXbLL0PG0# 查看节点(由于网络插件还没有部署,节点会没有准备就绪 NotReady)kubectl get node[root@master01 soft]# kubectl get nodeNAME       STATUS     ROLES    AGE   VERSIONmaster01   NotReady   <none>   27m   v1.20.14
5.3、部署kube-proxy

1)创建配置文件

cat > /opt/kubernetes/cfg/kube-proxy.conf << EOFKUBE_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 << EOFkind: KubeProxyConfigurationapiVersion: kubeproxy.config.k8s.io/v1alpha1bindAddress: 0.0.0.0metricsBindAddress: 0.0.0.0:10249clientConnection:  kubeconfig: /opt/kubernetes/cfg/kube-proxy.kubeconfighostnameOverride: master01clusterCIDR: 10.0.0.0/24EOF

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=";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 ProxyAfter=network.target[Service]EnvironmentFile=/opt/kubernetes/cfg/kube-proxy.confExecStart=/opt/kubernetes/bin/kube-proxy \$KUBE_PROXY_OPTSRestart=on-failureLimitNOFILE=65536[Install]WantedBy=multi-user.targetEOF

5)启动并设置开机启动

systemctl daemon-reloadsystemctl start kube-proxysystemctl enable kube-proxy
5.4、部署网络组件Calico

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。

下载地址:

# 部署Calicocurl  -Okubectl apply -f canal.yaml kubectl get pods -n kube-system[root@master01 soft]# kubectl get pods -n kube-systemNAME                                       READY   STATUS     RESTARTS   AGEcalico-kube-controllers-558995777d-mpnz6   0/1     Pending    0          3m38scanal-4pjbg                                0/2     Init:0/2   0          3m38s# 等Calico Pod都Running,节点也会准备就绪[root@master01 soft]# kubectl get pod -n kube-systemNAME                                       READY   STATUS    RESTARTS   AGEcalico-kube-controllers-558995777d-mpnz6   1/1     Running   0          22mcanal-4pjbg                                2/2     Running   0          22m[root@master01 soft]# kubectl get nodeNAME       STATUS   ROLES    AGE   VERSIONmaster01   Ready    <none>   47m   v1.20.14
5.5、授权apiserver访问kubelet

应用场景:例如kubectl logs

cat > apiserver-to-kubelet-rbac.yaml << EOFapiVersion: rbac.authorization.k8s.io/v1kind: ClusterRolemetadata:  annotations:    rbac.authorization.kubernetes.io/autoupdate: "true"  labels:    kubernetes.io/bootstrapping: rbac-defaults  name: system:kube-apiserver-to-kubeletrules:  - apiGroups:      - ""    resources:      - nodes/proxy      - nodes/stats      - nodes/log      - nodes/spec      - nodes/metrics      - pods/log    verbs:      - "*"---apiVersion: rbac.authorization.k8s.io/v1kind: ClusterRoleBindingmetadata:  name: system:kube-apiserver  namespace: ""roleRef:  apiGroup: rbac.authorization.k8s.io  kind: ClusterRole  name: system:kube-apiserver-to-kubeletsubjects:  - apiGroup: rbac.authorization.k8s.io    kind: User    name: kubernetesEOFkubectl apply -f apiserver-to-kubelet-rbac.yaml
5.6、新增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10.0.153.112/108scp -r /opt/kubernetes root@10.0.153.112:/opt/scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@10.0.153.112:/usr/lib/systemd/systemscp /opt/kubernetes/ssl/ca.pem root@10.0.153.112:/opt/kubernetes/sslscp -r /opt/kubernetes root@10.0.153.108:/opt/scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@10.0.153.108:/usr/lib/systemd/systemscp /opt/kubernetes/ssl/ca.pem root@10.0.153.108:/opt/kubernetes/ssl

2)删除kubelet证书和kubeconfig文件

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

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

3)修改配置文件中的主机名

vim /opt/kubernetes/cfg/kubelet.conf--hostname-override=node01vim /opt/kubernetes/cfg/kube-proxy-config.ymlhostnameOverride: node01

4)启动并设置开机启动

systemctl daemon-reloadsystemctl start kubelet kube-proxysystemctl enable kubelet kube-proxy

5)在Master上批准新Node kubelet证书申请

# 查看证书请求[root@master01 cfg]# kubectl get csrNAME                                                   AGE     SIGNERNAME                                    REQUESTOR           CONDITIONnode-csr-3qESVUkGeGoT97tLjq01G8IQ05ytMK8Jll0M4ZHba6c   2m58s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pendingnode-csr-5dm283moOkPBkGWiUacHXSievGGVmZkXFynXbLL0PG0   66m     kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Approved,Issued# 同意授权请求kubectl certificate approve node-csr-3qESVUkGeGoT97tLjq01G8IQ05ytMK8Jll0M4ZHba6c

6)查看Node状态

[root@master01 cfg]# kubectl get nodesNAME       STATUS   ROLES    AGE   VERSIONmaster01   Ready    <none>   87m   v1.20.14node01     Ready    <none>   26m   v1.20.14

Node2(10.0.153.108 )节点同上。记得修改主机名!

[root@master01 cfg]# kubectl get nodesNAME       STATUS   ROLES    AGE     VERSIONmaster01   Ready    <none>   94m     v1.20.14node01     Ready    <none>   33m     v1.20.14node02     Ready    <none>   2m37s   v1.20.14
六、部署Dashboard和CoreDNS6.1、部署Dashboard
url  apply -f  查看部署kubectl get pods,svc -n kubernetes-dashboard

访问地址:

建议改成nodeport访问

kubectl edit svc -n kubernetes-dashboard kubernetes-dashboard

[root@master01 cfg]# kubectl get pods,svc -n kubernetes-dashboardNAME                                             READY   STATUS    RESTARTS   AGEpod/dashboard-metrics-scraper-5b8896d7fc-lfjgm   1/1     Running   0          11mpod/kubernetes-dashboard-897c7599f-bmqbb         1/1     Running   0          11mNAME                                TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)    AGEservice/dashboard-metrics-scraper   ClusterIP   10.0.0.240   <none>        8000/TCP   11mservice/kubernetes-dashboard        ClusterIP   10.0.0.141   <none>        443/TCP    11m

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-systemkubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-adminkubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')eyJhbGciOiJSUzI1NiIsImtpZCI6IldfNWdZdlZoZ2FVWC1JM3NoQ3Nrb1lvRzZmd25CYXZuQ25KeWxOb1cxc2MifQ.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.s9HUT93YQ2jcfVsAWWfGSDnEoKbyhlQn4s4PRwR5amWd3rEdAcwXt_p2jZFKj64lvbzOzxPIncr1cLskhPWJmYYd-Ia2xH9LOGPm05kAQwE24GdZPHiHhtBMT6uKKyeXMo84yh1Fw9MEyr4i9hZxfmYULNYlIWazrEylpRiL3Zu0MNp0fDvC_X83oV-7KxssIbdQ2G1OneS2cyTSuGygufe6eU1elxELHAbnPByY6NXRSGlibOSIR3Q2i3WqP4DhP9XW2Iw0ptg1nG452BGS3h5NvoRIqwo1yuaDe1uFgXd3nyB8fkpmSyhda-7I9ltd_zFMs4GIRqoq6ijEGJL0CQ
也可以借鉴官方的部署方式和授权方式一键合成(感兴趣的伙伴可以测试下)

使用输出的token登录Dashboard:

dashboard

resources

6.2、部署CoreDNS

CoreDNS用于集群内部Service名称解析:

理解coredns 文章 github 此时需要修改coredns配置文件信息 建议拷贝上面的yaml文件内容
6.2.1 确认dns地址
cat /opt/kubernetes/cfg/kubelet-config.yml

6.2.2 修改coredns yaml文件

修改变量为图片显示

修改内存变量

修改clusterIP变量

6.2.3执行coredns.yaml

kubectl apply -f coredns.yaml  [root@master01 soft]# kubectl get po -ANAMESPACE              NAME                                         READY   STATUS    RESTARTS   AGEdefault                dns-test                                     1/1     Running   0          110skube-system            calico-kube-controllers-558995777d-844n4     1/1     Running   0          29skube-system            canal-gpk7z                                  2/2     Running   0          29skube-system            canal-mtpvc                                  2/2     Running   0          29skube-system            canal-zqhwl                                  2/2     Running   0          29skube-system            coredns-666c9bdf65-4g2m4                     1/1     Running   0          5m48skubernetes-dashboard   dashboard-metrics-scraper-5b8896d7fc-lfjgm   1/1     Running   0          13hkubernetes-dashboard   kubernetes-dashboard-897c7599f-ghljd         1/1     Running   0          3h15m

DNS解析测试:

但是我发现报错了参考报错文档但是并未解决我的问题后来思考是不是会和前面的callio有问题于是我卸载了这个 然后重新apply了一下cd /root/softkubectl delete -f canal.yaml kubectl apply -f canal.yaml kubectl run -it --rm dns-test --image=busybox:1.28.4 shIf you don't see a command prompt, try pressing enter./ # nslookup kubernetesServer:    10.0.0.2Address 1: 10.0.0.2 kube-dns.kube-system.svc.cluster.localName:      kubernetesAddress 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Master02 节点

现在需要再增加一台新服务器,作为Master02节点,IP是10.0.153.110。

Master02 与已部署的Master01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@10.0.153.110:/usr/binscp /usr/bin/runc root@10.0.153.110:/usr/binscp /usr/bin/containerd* root@10.0.153.110:/usr/binscp /usr/lib/systemd/system/docker.service root@10.0.153.110:/usr/lib/systemd/systemscp -r /etc/docker root@10.0.153.110:/etc# 在Master02启动Dockersystemctl daemon-reloadsystemctl start  dockersystemctl enable  docker

2)创建etcd证书目录

# 在Master02创建etcd证书目录mkdir -p /opt/etcd/ssl

3)拷贝master01上文件到master02

# 拷贝Master01上所有K8s文件和etcd证书到Master02scp -r /opt/kubernetes root@10.0.153.110:/optscp -r /opt/etcd/ssl root@10.0.153.110:/opt/etcdscp /usr/lib/systemd/system/kube* root@10.0.153.110:/usr/lib/systemd/systemscp /usr/bin/kubectl  root@10.0.153.110:/usr/binscp -r ~/.kube root@10.0.153.110:~

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、kube-controller-manager、kube-scheduler.kubeconfig 和kube-proxy配置文件为本地IPvim /opt/kubernetes/cfg/kube-apiserver.conf ...--bind-address=10.0.153.110 \--advertise-address=10.0.153.110 \...vim /opt/kubernetes/cfg/kubelet.conf--hostname-override=master02vim /opt/kubernetes/cfg/kube-proxy-config.ymlhostnameOverride: master02vim /opt/kubernetes/cfg/kube-controller-manager.kubeconfigserver:  /opt/kubernetes/cfg/kube-scheduler.kubeconfig server: 

6)启动并设置开机启动

systemctl daemon-reloadsystemctl start kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxysystemctl 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IPvim ~/.kube/config...server:  get csWarning: v1 ComponentStatus is deprecated in v1.19+NAME                 STATUS    MESSAGE             ERRORscheduler            Healthy   ok                  controller-manager   Healthy   ok                  etcd-2               Healthy   {"health":"true"}   etcd-1               Healthy   {"health":"true"}   etcd-0               Healthy   {"health":"true"}

8)批准kubelet证书申请

[root@master01 opt]# kubectl get csrNAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITIONnode-csr-pxYwf2q1JjhsifJRMIsAe5qxoBeOmU-HSv0GEnL-L50   42m   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending[root@master01 opt]# kubectl certificate approve node-csr-pxYwf2q1JjhsifJRMIsAe5qxoBeOmU-HSv0GEnL-L50certificatesigningrequest.certificates.k8s.io/node-csr-pxYwf2q1JjhsifJRMIsAe5qxoBeOmU-HSv0GEnL-L50 approved[root@master01 opt]# kubectl get nodesNAME       STATUS   ROLES    AGE   VERSIONmaster01   Ready    <none>   16h   v1.20.14node01     Ready    <none>   15h   v1.20.14node02     Ready    <none>   14h   v1.20.14
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 -yyum 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 $upstream_bytes_sent';    access_log  /var/log/nginx/k8s-access.log  main;    upstream k8s-apiserver {       server 10.0.153.109:6443;   # Master1 APISERVER IP:PORT       server 10.0.153.110:6443;   # Master2 APISERVER IP:PORT    }        server {       listen 16443; # 由于nginx与master节点复用,这个监听端口不能是6443,否则会冲突       proxy_pass k8s-apiserver;    }}http {    log_format  main  '$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 << EOFglobal_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 eth0 # 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 {         10.0.153.88/24    }     track_script {        check_nginx    } }EOF

参数说明:

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/bashcount=$(ss -antp |grep 16443 |egrep -cv "grep|$$")if [ "$count" -eq 0 ];then    exit 1else    exit 0fiEOFchmod +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

4)keepalived配置文件(Nginx Backup)

cat > /etc/keepalived/keepalived.conf << EOFglobal_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 eth0    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 {         10.0.153.88/24    }     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/bashcount=$(ss -antp |grep 16443 |egrep -cv "grep|$$")if [ "$count" -eq 0 ];then    exit 1else    exit 0fiEOFchmod +x /etc/keepalived/check_nginx.sh

5)启动并设置开机启动

systemctl daemon-reloadsystemctl start nginx keepalivedsystemctl enable nginx keepalived如果nginx启动报错 缺少stream模块 参考文档

6)查看keepalived工作状态

可以看到,在eth0网卡绑定了10.0.0.88 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systemctl stop 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:

[root@master02 cfg]# curl -k {  "major": "1",  "minor": "20",  "gitVersion": "v1.20.14",  "gitCommit": "57a3aa3f13699cf3db9c52d228c18db94fa81876",  "gitTreeState": "clean",  "buildDate": "2021-12-15T14:47:10Z",  "goVersion": "go1.15.15",  "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 -f /var/log/nginx/k8s-access.log10.0.153.110 10.0.153.109:6443 - [25/Dec/2021:16:23:26 +0800] 200 419

9)修改所有Worker Node连接LB VIP

试想下,虽然我们增加了Master02 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Master01 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10.0.153.109修改为10.0.153.88(VIP)。

在所有Worker Node执行:

sed -i 's#10.0.153.109:6443#10.0.153.88:16443#' /opt/kubernetes/cfg/*systemctl restart kubelet kube-proxy

检查节点状态:

[root@master01 nginx-1.20.1]# kubectl get nodesNAME       STATUS   ROLES    AGE   VERSIONmaster01   Ready    <none>   17h   v1.20.14master02   Ready    <none>   45m   v1.20.14node01     Ready    <none>   16h   v1.20.14node02     Ready    <none>   15h   v1.20.14

至此,一套完整的 Kubernetes 高可用集群就部署完成了!

欢迎入群交流

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