二进制搭建k8s高可用集群

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。

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

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

单节点架构图

# 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 master01 10.0.153.110 master02 10.0.153.112 node01 10.0.153.108 node02 EOF # 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

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 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-certinfo2.2、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 # 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 server2.3、部署Etcd集群

1）下载etcd二进制文件

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

2）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/

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="https://10.0.153.109:2380" ETCD_LISTEN_CLIENT_URLS="https://10.0.153.109:2379" #[Clustering] ETCD_INITIAL_ADVERTISE_PEER_URLS="https://10.0.153.109:2380" ETCD_ADVERTISE_CLIENT_URLS="https://10.0.153.109:2379" ETCD_INITIAL_CLUSTER="etcd-1=https://10.0.153.109:2380,etcd-2=https://10.0.153.112:2380,etcd-3=https://10.0.153.108:2380" 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 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

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-reload systemctl start etcd systemctl 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-3 ETCD_DATA_DIR="/var/lib/etcd/default.etcd" ETCD_LISTEN_PEER_URLS="https://10.0.153.109:2380" # 修改此处为当前服务器IP ETCD_LISTEN_CLIENT_URLS="https://10.0.153.109:2379" # 修改此处为当前服务器IP #[Clustering] ETCD_INITIAL_ADVERTISE_PEER_URLS="https://10.0.153.109:2380" # 修改此处为当前服务器IP ETCD_ADVERTISE_CLIENT_URLS="https://10.0.153.109:2379" # 修改此处为当前服务器IP ETCD_INITIAL_CLUSTER="etcd-1=https://10.0.153.109:2380,etcd-2=https://10.0.153.112:2380,etcd-3=https://10.0.153.108:2380" ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster" ETCD_INITIAL_CLUSTER_STATE="new"

9）启动etcd并设置开机启动

systemctl daemon-reload systemctl start etcd systemctl 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="https://10.0.153.109:2379,https://10.0.153.112:2379,https://10.0.153.108:2379" endpoint health --write-out=table # 显示结果如下，说明部署成功 --------------------------- -------- ------------- ------- | ENDPOINT | HEALTH | TOOK | ERROR | --------------------------- -------- ------------- ------- | https://10.0.153.109:2379 | true | 10.008247ms | | | https://10.0.153.108:2379 | true | 17.968196ms | | | https://10.0.153.112:2379 | 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：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。

1）解压二进制软件包

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

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）创建配置文件

mkdir /etc/docker cat > /etc/docker/daemon.json << EOF { "registry-mirrors": ["https://8fhres1d.mirror.aliyuncs.com"] } EOF

4）启动并设置开机启动

systemctl daemon-reload systemctl start docker systemctl 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/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：生成ca.pem和ca-key.pem文件 ca4.1.2、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.pem cfssl 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：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

https://dl.k8s.io/v1.20.14/kubernetes-server-linux-amd64.tar.gz

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.gz cd kubernetes/server/bin cp kube-apiserver kube-scheduler kube-controller-manager /opt/kubernetes/bin cp kubectl /usr/bin/

2）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://10.0.153.109:2379,https://10.0.153.112:2379,https://10.0.153.108:2379 \\ --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 << EOF f18f49462c7d24a68aeeb5c75b093943,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 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

7）启动并设置开机启动

systemctl daemon-reload systemctl 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 << 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

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="https://10.0.153.109:6443" 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 4.3、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

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="https://10.0.153.109:6443" 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://10.0.153.109:6443" 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 # 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 ERROR scheduler 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

# 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/bin cp kubelet kube-proxy /opt/kubernetes/bin 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=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 << 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://10.0.153.109:6443" # apiserver IP:PORT TOKEN="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 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

6）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-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 node NAME STATUS ROLES AGE VERSION master01 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 << 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: master01 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://10.0.153.109:6443" 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 5.4、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：https://projectcalico.docs.tigera.io/getting-started/kubernetes/flannel/flannel

# 部署Calico curl https://docs.projectcalico.org/manifests/canal.yaml -O kubectl apply -f canal.yaml kubectl get pods -n kube-system [root@master01 soft]# kubectl get pods -n kube-system NAME READY STATUS RESTARTS AGE calico-kube-controllers-558995777d-mpnz6 0/1 Pending 0 3m38s canal-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-system NAME READY STATUS RESTARTS AGE calico-kube-controllers-558995777d-mpnz6 1/1 Running 0 22m canal-4pjbg 2/2 Running 0 22m [root@master01 soft]# kubectl get node NAME STATUS ROLES AGE VERSION master01 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 << 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.yaml5.6、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10.0.153.112/108 scp -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/system scp /opt/kubernetes/ssl/ca.pem root@10.0.153.112:/opt/kubernetes/ssl scp -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/system scp /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=node01 vim /opt/kubernetes/cfg/kube-proxy-config.yml hostnameOverride: node01

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 [root@master01 cfg]# kubectl get csr NAME AGE SIGNERNAME REQUESTOR CONDITION node-csr-3qESVUkGeGoT97tLjq01G8IQ05ytMK8Jll0M4ZHba6c 2m58s kubernetes.io/kube-apiserver-client-kubelet kubelet-bootstrap Pending node-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 nodes NAME STATUS ROLES AGE VERSION master01 Ready <none> 87m v1.20.14 node01 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 nodes NAME STATUS ROLES AGE VERSION master01 Ready <none> 94m v1.20.14 node01 Ready <none> 33m v1.20.14 node02 Ready <none> 2m37s v1.20.14六、部署Dashboard和CoreDNS6.1、部署Dashboard

url https://kubernetes.io/docs/tasks/access-application-cluster/web-ui-dashboard/ kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.4.0/aio/deploy/recommended.yaml # 查看部署 kubectl get pods,svc -n kubernetes-dashboard

访问地址：https://NodeIP:30080

建议改成nodeport访问

kubectl edit svc -n kubernetes-dashboard kubernetes-dashboard

[root@master01 cfg]# kubectl get pods,svc -n kubernetes-dashboard NAME READY STATUS RESTARTS AGE pod/dashboard-metrics-scraper-5b8896d7fc-lfjgm 1/1 Running 0 11m pod/kubernetes-dashboard-897c7599f-bmqbb 1/1 Running 0 11m NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/dashboard-metrics-scraper ClusterIP 10.0.0.240 <none> 8000/TCP 11m service/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-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}') 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) https://github.com/kubernetes/kubernetes/blob/master/cluster/addons/dashboard/dashboard.yaml

使用输出的token登录Dashboard：

dashboard

resources

CoreDNS用于集群内部Service名称解析：

理解coredns 文章 https://draveness.me/dns-coredns/ github https://github.com/kubernetes/kubernetes/blob/master/cluster/addons/dns/coredns/coredns.yaml.base 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

修改变量为图片显示

修改内存变量

修改clusterIP变量

kubectl apply -f coredns.yaml [root@master01 soft]# kubectl get po -A NAMESPACE NAME READY STATUS RESTARTS AGE default dns-test 1/1 Running 0 110s kube-system calico-kube-controllers-558995777d-844n4 1/1 Running 0 29s kube-system canal-gpk7z 2/2 Running 0 29s kube-system canal-mtpvc 2/2 Running 0 29s kube-system canal-zqhwl 2/2 Running 0 29s kube-system coredns-666c9bdf65-4g2m4 1/1 Running 0 5m48s kubernetes-dashboard dashboard-metrics-scraper-5b8896d7fc-lfjgm 1/1 Running 0 13h kubernetes-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https://www.cnblogs.com/Tempted/p/15602850.html 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/soft kubectl delete -f canal.yaml kubectl apply -f canal.yaml 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！

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：

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/bin scp /usr/bin/runc root@10.0.153.110:/usr/bin scp /usr/bin/containerd* root@10.0.153.110:/usr/bin scp /usr/lib/systemd/system/docker.service root@10.0.153.110:/usr/lib/systemd/system scp -r /etc/docker root@10.0.153.110:/etc # 在Master02启动Docker systemctl daemon-reload systemctl start docker systemctl 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Master02 scp -r /opt/kubernetes root@10.0.153.110:/opt scp -r /opt/etcd/ssl root@10.0.153.110:/opt/etcd scp /usr/lib/systemd/system/kube* root@10.0.153.110:/usr/lib/systemd/system scp /usr/bin/kubectl root@10.0.153.110:/usr/bin scp -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IP vim /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=master02 vim /opt/kubernetes/cfg/kube-proxy-config.yml hostnameOverride: master02 vim /opt/kubernetes/cfg/kube-controller-manager.kubeconfig server: https://10.0.153.110:6443 vim /opt/kubernetes/cfg/kube-scheduler.kubeconfig server: https://10.0.153.110:6443

6）启动并设置开机启动

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 vim ~/.kube/config ... server: https://10.0.153.110:6443 kubectl get cs Warning: v1 ComponentStatus is deprecated in v1.19 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"}

8）批准kubelet证书申请

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

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 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/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

5）启动并设置开机启动

systemctl daemon-reload systemctl start nginx keepalived systemctl enable nginx keepalived 如果nginx启动报错 缺少stream模块 参考文档 https://www.cnblogs.com/even160941/p/15064925.html

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 https://10.0.153.88:16443/version { "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.log 10.0.153.110 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 nodes NAME STATUS ROLES AGE VERSION master01 Ready <none> 17h v1.20.14 master02 Ready <none> 45m v1.20.14 node01 Ready <none> 16h v1.20.14 node02 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