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16_CKA_Kubeadm高可用安装k8s集群

2021年6月17日 20:21 作者：金淼淋 分类：Kubernetes 1.85K

Kubeadm高可用安装k8s集群

​ 请不要使用带中文的服务器和克隆的虚拟机

​ 生产环境建议使用二进制安装方式

​ 文档中的IP地址请统一替换，不要一个一个替换！！！

k8s高可用架构解析

image-20210615111641645

  • ETCD Cluster 负责存储数据
  • Master 负责控制集群
  • Node 负责运行容器提供服务

基本环境配置

高可用Kubernetes集群规划

主机名 IP地址 说明
k8s-master01 ~ 03 192.168.101.81 ~ 83 master节点 * 3
k8s-master-lb 192.168.101.236 keepalived虚拟IP
k8s-node01 ~ 02 192.168.101.84~ 85 worker节点 * 2

配置信息

配置信息 备注
系统版本 CentOS 7.4
Docker版本 19.03.x
Pod网段 172.168.0.0/12
Service网段 10.96.0.0/12
  • CentOS 7安装yum源如下
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo
  • hosts修改(每台主机)
[root@vms83 ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.101.81 k8s-master01
192.168.101.82 k8s-master02
192.168.101.83 k8s-master03
192.168.101.236 k8s-master-lb #如果不是高可用群集,该IP为master01的IP
192.168.101.84 k8s-node01
192.168.101.85 k8s-node02
  • 安装常用工具
yum install wget jq psmisc vim net-tools telnet yum-utils device-mapper-persistent-data lvm2 git -y
  • 关闭防火墙
systemctl disable --now firewalld 
systemctl disable --now dnsmasq
systemctl disable --now NetworkManager

setenforce 0
sed -i 's#SELINUX=enforcing#SELINUX=disabled#g' /etc/sysconfig/selinux
sed -i 's#SELINUX=enforcing#SELINUX=disabled#g' /etc/selinux/config
  • 关闭swap分区

    在k8s中不推荐使用swap.

swapoff -a && sysctl -w vm.swappiness=0
sed -ri '/^[^#]*swap/s@^@#@' /etc/fstab

  • 安装ntpdate

    如果服务器时间不一致会导致k8s中证书认证出现问题,如果公司存在NTP服务器使用NTP即可.

rpm -ivh http://mirrors.wlnmp.com/centos/wlnmp-release-centos.noarch.rpm
yum install ntpdate -y

ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
echo 'Asia/Shanghai' >/etc/timezone
ntpdate time2.aliyun.com


# 加入到crontab
crontab -e
*/5 * * * * /usr/sbin/ntpdate time2.aliyun.com

  • 所有节点配置limit：

    临时生效需要在修改配置文件.

ulimit -SHn 65535

vim /etc/security/limits.conf
# 末尾添加如下内容
* soft nofile 655360
* hard nofile 131072
* soft nproc 655350
* hard nproc 655350
* soft memlock unlimited
* hard memlock unlimited

​ Master01节点免密钥登录其他节点，安装过程中生成配置文件和证书均在Master01上操作，集群管理也在Master01上操作，阿里云或者AWS上需要单独一台kubectl服务器。

密钥配置如下：

ssh-keygen -t rsa
for i in k8s-master01 k8s-master02 k8s-master03 k8s-node01 k8s-node02;do ssh-copy-id -i .ssh/id_rsa.pub $i;done

下载安装所有的源码文件：

cd /root/ ; git clone https://github.com/dotbalo/k8s-ha-install.git

所有节点升级系统并重启，此处升级没有升级内核，下节会单独升级内核：

yum update -y --exclude=kernel* && reboot #CentOS7需要升级，CentOS8可以按需升级系统

内核配置

CentOS7 需要升级内核至4.18+，本地升级的版本为4.19

​ 在master01节点下载内核：

cd /root
wget http://193.49.22.109/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-devel-4.19.12-1.el7.elrepo.x86_64.rpm
wget http://193.49.22.109/elrepo/kernel/el7/x86_64/RPMS/kernel-ml-4.19.12-1.el7.elrepo.x86_64.rpm

​ 从master01节点传到其他节点：

for i in k8s-master02 k8s-master03 k8s-node01 k8s-node02;do scp kernel-ml-4.19.12-1.el7.elrepo.x86_64.rpm kernel-ml-devel-4.19.12-1.el7.elrepo.x86_64.rpm $i:/root/ ; done

​ 所有节点安装内核

cd /root && yum localinstall -y kernel-ml*

​ 所有节点更改内核启动顺序

grub2-set-default  0 && grub2-mkconfig -o /etc/grub2.cfg

grubby --args="user_namespace.enable=1" --update-kernel="$(grubby --default-kernel)"

​ 检查默认内核是不是4.19

[root@k8s-master02 ~]# grubby --default-kernel
/boot/vmlinuz-4.19.12-1.el7.elrepo.x86_64

​ 所有节点重启，然后检查内核是不是4.19

[root@k8s-master02 ~]# uname -a
Linux k8s-master02 4.19.12-1.el7.elrepo.x86_64 #1 SMP Fri Dec 21 11:06:36 EST 2018 x86_64 x86_64 x86_64 GNU/Linux

​ 所有节点安装ipvsadm：(生产环境中不推荐使用iptables,所以要使用ipvsadm)

yum install ipvsadm ipset sysstat conntrack libseccomp -y

​ 所有节点配置ipvs模块，在内核4.19+版本nf_conntrack_ipv4已经改为nf_conntrack， 4.18以下使用nf_conntrack_ipv4即可：

modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack

vim /etc/modules-load.d/ipvs.conf 
    # 加入以下内容
ip_vs
ip_vs_lc
ip_vs_wlc
ip_vs_rr
ip_vs_wrr
ip_vs_lblc
ip_vs_lblcr
ip_vs_dh
ip_vs_sh
ip_vs_fo
ip_vs_nq
ip_vs_sed
ip_vs_ftp
ip_vs_sh
nf_conntrack # 4.18以下nf_conntrack_ipv4
ip_tables
ip_set
xt_set
ipt_set
ipt_rpfilter
ipt_REJECT
ipip

​ 然后执行systemctl enable --now systemd-modules-load.service即可.

​ 检查是否加载.

# lsmod | grep -e ip_vs -e nf_conntrack
nf_conntrack_netlink    40960  0
nfnetlink              16384  2 nf_conntrack_netlink
nf_conntrack          143360  5 xt_conntrack,nf_nat,ipt_MASQUERADE,nf_nat_ipv4,nf_conntrack_netlink
nf_defrag_ipv6         20480  1 nf_conntrack
nf_defrag_ipv4         16384  1 nf_conntrack
libcrc32c              16384  3 nf_conntrack,nf_nat,xfs

​

​ 开启一些k8s集群中必须的内核参数，所有节点配置k8s内核：

cat <<EOF > /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
fs.may_detach_mounts = 1
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_watches=89100
fs.file-max=52706963
fs.nr_open=52706963
net.netfilter.nf_conntrack_max=2310720

net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl =15
net.ipv4.tcp_max_tw_buckets = 36000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_max_orphans = 327680
net.ipv4.tcp_orphan_retries = 3
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.ip_conntrack_max = 65536
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_timestamps = 0
net.core.somaxconn = 16384
EOF

sysctl --system

​ 所有节点配置完内核后，重启服务器，保证重启后内核依旧加载.

reboot
lsmod | grep --color=auto -e ip_vs -e nf_conntrack

基本组件安装

​ 本节主要安装的是集群中用到的各种组件，比如Docker-ce、Kubernetes各组件等。

所有节点安装Docker-ce 19.03

yum install docker-ce-19.03.* docker-cli-19.03.* -y

温馨提示：

​ 由于新版kubelet建议使用systemd，所以可以把docker的CgroupDriver改成systemd

mkdir /etc/docker
cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"]
}
EOF

​ 所有节点设置开机自启动Docker：

​ systemctl daemon-reload && systemctl enable --now docker

安装k8s组件：(生产环境中建议小版本号大于5以后在使用)

​ yum list kubeadm.x86_64 --showduplicates | sort -r

kubeadm.x86_64                       1.20.5-0                         kubernetes

所有节点安装最新版本kubeadm：

​ yum install kubeadm-1.20* kubelet-1.20* kubectl-1.20* -y

默认配置的pause镜像使用gcr.io仓库，国内可能无法访问，所以这里配置Kubelet使用阿里云的pause镜像：

cat >/etc/sysconfig/kubelet<<EOF
KUBELET_EXTRA_ARGS="--cgroup-driver=systemd --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.2"
EOF

设置Kubelet开机自启动：

systemctl daemon-reload
systemctl enable --now kubelet

高可用组件安装

（注意：如果不是高可用集群，haproxy和keepalived无需安装）

公有云要用公有云自带的负载均衡，比如阿里云的SLB，腾讯云的ELB，用来替代haproxy和keepalived，因为公有云大部分都是不支持keepalived的，另外如果用阿里云的话，kubectl控制端不能放在master节点，推荐使用腾讯云，因为阿里云的slb有回环的问题，也就是slb代理的服务器不能反向访问SLB，但是腾讯云修复了这个问题。

所有Master节点通过yum安装HAProxy和KeepAlived：

​ yum install keepalived haproxy -y

所有Master节点配置HAProxy（详细配置参考HAProxy文档，所有Master节点的HAProxy配置相同）：

[root@k8s-master01 etc]# mkdir /etc/haproxy
[root@k8s-master01 etc]# vim /etc/haproxy/haproxy.cfg 
global
  maxconn  2000
  ulimit-n  16384
  log  127.0.0.1 local0 err
  stats timeout 30s

defaults
  log global
  mode  http
  option  httplog
  timeout connect 5000
  timeout client  50000
  timeout server  50000
  timeout http-request 15s
  timeout http-keep-alive 15s

frontend monitor-in
  bind *:33305
  mode http
  option httplog
  monitor-uri /monitor

frontend k8s-master
  bind 0.0.0.0:16443
  bind 127.0.0.1:16443
  mode tcp
  option tcplog
  tcp-request inspect-delay 5s
  default_backend k8s-master

backend k8s-master
  mode tcp
  option tcplog
  option tcp-check
  balance roundrobin
  default-server inter 10s downinter 5s rise 2 fall 2 slowstart 60s maxconn 250 maxqueue 256 weight 100
  server k8s-master01   192.168.101.81:6443  check
  server k8s-master02   192.168.101.82:6443  check
  server k8s-master03   192.168.101.83:6443  check

所有Master节点配置KeepAlived，配置不一样，注意区分 [root@k8s-master01 pki]# vim /etc/keepalived/keepalived.conf ，注意每个节点的IP和网卡（interface参数）

Master01节点的配置：

[root@k8s-master01 etc]# mkdir /etc/keepalived

[root@k8s-master01 ~]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
global_defs {
    router_id LVS_DEVEL
script_user root
    enable_script_security
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
    interval 5
    weight -5
    fall 2  
rise 1
}
vrrp_instance VI_1 {
    state MASTER
    interface ens32
    mcast_src_ip 192.168.101.81
    virtual_router_id 51
    priority 101
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        192.168.101.236
    }
    track_script {
       chk_apiserver
    }
}

Master02节点的配置：

! Configuration File for keepalived
global_defs {
    router_id LVS_DEVEL
script_user root
    enable_script_security
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
   interval 5
    weight -5
    fall 2  
rise 1
}
vrrp_instance VI_1 {
    state BACKUP
    interface ens32
    mcast_src_ip 192.168.101.82
    virtual_router_id 51
    priority 100
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        192.168.101.236
    }
    track_script {
       chk_apiserver
    }
}

Master03节点的配置：

! Configuration File for keepalived
global_defs {
    router_id LVS_DEVEL
script_user root
    enable_script_security
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
 interval 5
    weight -5
    fall 2  
rise 1
}
vrrp_instance VI_1 {
    state BACKUP
    interface ens32
    mcast_src_ip 192.168.101.83
    virtual_router_id 51
    priority 100
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        192.168.101.236
    }
    track_script {
       chk_apiserver
    }
}

所有master节点配置KeepAlived健康检查文件：

[root@k8s-master01 keepalived]# cat /etc/keepalived/check_apiserver.sh 
#!/bin/bash

err=0
for k in (seq 1 3)
do
    check_code=(pgrep haproxy)
    if [[ check_code == "" ]]; then
        err=(expr err + 1)
        sleep 1
        continue
    else
        err=0
        break
    fi
done

if [[err != "0" ]]; then
    echo "systemctl stop keepalived"
    /usr/bin/systemctl stop keepalived
    exit 1
else
    exit 0
fi

chmod +x /etc/keepalived/check_apiserver.sh

启动haproxy和keepalived

[root@k8s-master01 keepalived]# systemctl daemon-reload
[root@k8s-master01 keepalived]# systemctl enable --now haproxy
[root@k8s-master01 keepalived]# systemctl enable --now keepalived

重要：如果安装了keepalived和haproxy，需要测试keepalived是否是正常的

测试VIP
[root@k8s-master01 ~]# ping 192.168.101.236 -c 4
PING 192.168.101.236 (192.168.101.236) 56(84) bytes of data.
64 bytes from 192.168.101.236: icmp_seq=1 ttl=64 time=0.464 ms
64 bytes from 192.168.101.236: icmp_seq=2 ttl=64 time=0.063 ms
64 bytes from 192.168.101.236: icmp_seq=3 ttl=64 time=0.062 ms
64 bytes from 192.168.101.236: icmp_seq=4 ttl=64 time=0.063 ms

--- 192.168.101.236 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3106ms
rtt min/avg/max/mdev = 0.062/0.163/0.464/0.173 ms
[root@k8s-master01 ~]# telnet 192.168.101.236 16443
Trying 192.168.101.236...
Connected to 192.168.101.236.
Escape character is '^]'.
Connection closed by foreign host.

如果ping不通且telnet没有出现，则认为VIP不可以，不可在继续往下执行，需要排查keepalived的问题，比如防火墙和selinux，haproxy和keepalived的状态，监听端口等

所有节点查看防火墙状态必须为disable和inactive：systemctl status firewalld

所有节点查看selinux状态，必须为disable：getenforce

master节点查看haproxy和keepalived状态：systemctl status keepalived haproxy

master节点查看监听端口：netstat -lntp

集群初始化

官方初始化文档：

https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/high-availability/

Master01节点创建kubeadm-config.yaml配置文件如下：

​ Master01：（# 注意，如果不是高可用集群，192.168.101.236:16443改为master01的地址，16443改为apiserver的端口，默认是6443，注意更改 kubernetesVersion: v1.20.0自己服务器kubeadm的版本：kubeadm version）

apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: 7t2weq.bjbawausm0jaxury
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 192.168.101.81
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: k8s-master01
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master
---
apiServer:
  certSANs:
  - 192.168.101.236
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: 192.168.101.236:16443
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.20.7
networking:
  dnsDomain: cluster.local
  podSubnet: 172.168.0.0/12
  serviceSubnet: 10.96.0.0/12
scheduler: {}

更新kubeadm文件

kubeadm config migrate --old-config kubeadm-config.yaml --new-config new.yaml

将new.yaml文件复制到其他master节点，之后所有Master节点提前下载镜像，可以节省初始化时间：

kubeadm config images pull --config /root/new.yaml

所有节点设置开机自启动kubelet

systemctl enable --now kubelet #（如果启动失败无需管理，初始化成功以后即可启动）

Master01节点初始化，初始化以后会在/etc/kubernetes目录下生成对应的证书和配置文件，之后其他Master节点加入Master01即可：

kubeadm init --config /root/new.yaml  --upload-certs

如果初始化失败，重置后再次初始化，命令如下：

kubeadm reset -f ; ipvsadm --clear  ; rm -rf ~/.kube

初始化成功以后，会产生Token值，用于其他节点加入时使用，因此要记录下初始化成功生成的token值（令牌值）：

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p HOME/.kube
  sudo cp -i /etc/kubernetes/admin.confHOME/.kube/config
  sudo chown (id -u):(id -g) $HOME/.kube/config

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of the control-plane node running the following command on each as root:

  kubeadm join 192.168.101.236:16443 --token 7t2weq.bjbawausm0jaxury \
    --discovery-token-ca-cert-hash sha256:7fa565148baf1c2b15a7e0085cc08f5f54f4457b8b232a6ea94dc30fcd6c4815 \
    --control-plane --certificate-key a7c80975339aa4a26c7fbe01fbd44902dbdf0dfd4af3fd4fe36a49d9ea683db5

Please note that the certificate-key gives access to cluster sensitive data, keep it secret!
As a safeguard, uploaded-certs will be deleted in two hours; If necessary, you can use
"kubeadm init phase upload-certs --upload-certs" to reload certs afterward.

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 192.168.101.236:16443 --token 7t2weq.bjbawausm0jaxury \
    --discovery-token-ca-cert-hash sha256:7fa565148baf1c2b15a7e0085cc08f5f54f4457b8b232a6ea94dc30fcd6c4815

Master01节点配置环境变量，用于访问Kubernetes集群：

cat <<EOF >> /root/.bashrc
export KUBECONFIG=/etc/kubernetes/admin.conf
EOF
source /root/.bashrc

查看节点状态：

 [root@k8s-master01 ~]# kubectl get nodes
NAME           STATUS     ROLES                  AGE   VERSION
k8s-master01   NotReady   control-plane,master   74s   v1.20.0

采用初始化安装方式，所有的系统组件均以容器的方式运行并且在kube-system命名空间内，此时可以查看Pod状态：

[root@k8s-master01 ~]# kubectl get pods -n kube-system -o wide
NAME                                   READY     STATUS    RESTARTS   AGE       IP              NODE
coredns-777d78ff6f-kstsz               0/1       Pending   0          14m       <none>          <none>
coredns-777d78ff6f-rlfr5               0/1       Pending   0          14m       <none>          <none>
etcd-k8s-master01                      1/1       Running   0          14m       192.168.101.81   k8s-master01
kube-apiserver-k8s-master01            1/1       Running   0          13m       192.168.101.81   k8s-master01
kube-controller-manager-k8s-master01   1/1       Running   0          13m       192.168.101.81   k8s-master01
kube-proxy-8d4qc                       1/1       Running   0          14m       192.168.101.81   k8s-master01
kube-scheduler-k8s-master01            1/1       Running   0          13m       192.168.101.81   k8s-master01

高可用Master

Token过期后生成新的token：

​ kubeadm token create --print-join-command

Master需要生成–certificate-ke

​ kubeadm init phase upload-certs --upload-certs

初始化其他master加入集群(master节点和node节点只有control-plane存不存在的区别)

  kubeadm join 192.168.101.236:16443 --token 7t2weq.bjbawausm0jaxury \
    --discovery-token-ca-cert-hash sha256:64e5044e3d26176b3a6c7d4bcd35dc03852387ff2d8b7fc7e35e9d519fd3d8f4 \
    --control-plane --certificate-key b66d9b83d0f8833466c0fa6821c0115703049e4e2ffa769825e727a599493c4b

将 master 节点服务器从 k8s 集群中移除并重新加入

kubectl drain blog-k8s-n0
kubectl delete node blog-k8s-n0

Node节点的配置

Node节点上主要部署公司的一些业务应用，生产环境中不建议Master节点部署系统组件之外的其他Pod，测试环境可以允许Master节点部署Pod以节省系统资源。

  kubeadm join 192.168.101.236:16443 --token 7t2weq.bjbawausm0jaxury \
    --discovery-token-ca-cert-hash sha256:64e5044e3d26176b3a6c7d4bcd35dc03852387ff2d8b7fc7e35e9d519fd3d8f4

所有节点初始化完成后，查看集群状态

[root@k8s-master01]# kubectl  get node
NAME           STATUS     ROLES                  AGE     VERSION
k8s-master01   NotReady   control-plane,master   8m53s   v1.20.0
k8s-master02   NotReady   control-plane,master   2m25s   v1.20.0
k8s-master03   NotReady   control-plane,master   31s     v1.20.0
k8s-node01     NotReady   <none>                 32s     v1.20.0
k8s-node02     NotReady   <none>                 88s     v1.20.0

Calico组件的安装

以下步骤只在master01执行

cd /root/k8s-ha-install && git checkout manual-installation-v1.20.x && cd calico/

修改calico-etcd.yaml的以下位置

sed -i 's#etcd_endpoints: "http://<ETCD_IP>:<ETCD_PORT>"#etcd_endpoints: "https://192.168.101.81:2379,https://192.168.101.82:2379,https://192.168.101.83:2379"#g' calico-etcd.yaml

ETCD_CA=`cat /etc/kubernetes/pki/etcd/ca.crt | base64 | tr -d '\n'`
ETCD_CERT=`cat /etc/kubernetes/pki/etcd/server.crt | base64 | tr -d '\n'`
ETCD_KEY=`cat /etc/kubernetes/pki/etcd/server.key | base64 | tr -d '\n'`

sed -i "s@# etcd-key: null@etcd-key: {ETCD_KEY}@g; s@# etcd-cert: null@etcd-cert:{ETCD_CERT}@g; s@# etcd-ca: null@etcd-ca: {ETCD_CA}@g" calico-etcd.yaml

sed -i 's#etcd_ca: ""#etcd_ca: "/calico-secrets/etcd-ca"#g; s#etcd_cert: ""#etcd_cert: "/calico-secrets/etcd-cert"#g; s#etcd_key: "" #etcd_key: "/calico-secrets/etcd-key" #g' calico-etcd.yaml

POD_SUBNET=`cat /etc/kubernetes/manifests/kube-controller-manager.yaml | grep cluster-cidr= | awk -F= '{printNF}'`

注意下面的这个步骤是把calico-etcd.yaml文件里面的CALICO_IPV4POOL_CIDR下的网段改成自己的Pod网段，也就是把192.168.x.x/16改成自己的集群网段，并打开注释：

image-20210615224209354

所以更改的时候请确保这个步骤的这个网段没有被统一替换掉，如果被替换掉了，还请改回来：

image-20210615224256413

sed -i 's@# - name: CALICO_IPV4POOL_CIDR@- name: CALICO_IPV4POOL_CIDR@g; s@#   value: "192.168.0.0/16"@  value: '"${POD_SUBNET}"'@g' calico-etcd.yaml

kubectl apply -f calico-etcd.yaml

查看容器状态

[root@k8s-master01 calico]# kubectl  get po -n kube-system
NAME                                       READY   STATUS    RESTARTS   AGE
calico-kube-controllers-5f6d4b864b-pwvnb   1/1     Running   0          3m29s
calico-node-5lz9m                          1/1     Running   0          3m29s
calico-node-8z4bg                          1/1     Running   0          3m29s
calico-node-lmzvf                          1/1     Running   0          3m29s
calico-node-mpngv                          1/1     Running   0          3m29s
calico-node-vmqsl                          1/1     Running   0          3m29s
coredns-54d67798b7-8525g                   1/1     Running   0          39m
coredns-54d67798b7-fxs72                   1/1     Running   0          39m
etcd-k8s-master01                          1/1     Running   0          39m
etcd-k8s-master02                          1/1     Running   0          33m
etcd-k8s-master03                          1/1     Running   0          31m
kube-apiserver-k8s-master01                1/1     Running   0          39m
kube-apiserver-k8s-master02                1/1     Running   0          33m
kube-apiserver-k8s-master03                1/1     Running   0          30m
kube-controller-manager-k8s-master01       1/1     Running   1          39m
kube-controller-manager-k8s-master02       1/1     Running   0          33m
kube-controller-manager-k8s-master03       1/1     Running   0          31m
kube-proxy-hnkmj                           1/1     Running   0          39m
kube-proxy-jk4dm                           1/1     Running   0          32m
kube-proxy-nbcg2                           1/1     Running   0          32m
kube-proxy-qv9k7                           1/1     Running   0          32m
kube-proxy-x6xdc                           1/1     Running   0          33m
kube-scheduler-k8s-master01                1/1     Running   1          39m
kube-scheduler-k8s-master02                1/1     Running   0          33m
kube-scheduler-k8s-master03                1/1     Running   0          30m

Metrics部署

在新版的Kubernetes中系统资源的采集均使用Metrics-server，可以通过Metrics采集节点和Pod的内存、磁盘、CPU和网络的使用率。

将Master01节点的front-proxy-ca.crt复制到所有Node节点

scp /etc/kubernetes/pki/front-proxy-ca.crt k8s-node01:/etc/kubernetes/pki/front-proxy-ca.crt
scp /etc/kubernetes/pki/front-proxy-ca.crt k8s-node(其他节点自行拷贝):/etc/kubernetes/pki/front-proxy-ca.crt

安装metrics server

cd /root/k8s-ha-install/metrics-server-0.4.x-kubeadm/

[root@k8s-master01 metrics-server-0.4.x-kubeadm]# kubectl  create -f comp.yaml 
serviceaccount/metrics-server created
clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader created
clusterrole.rbac.authorization.k8s.io/system:metrics-server created
rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created
clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created
clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created
service/metrics-server created
deployment.apps/metrics-server created
apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created

查看状态

[root@k8s-master01 metrics-server-0.4.x-kubeadm]# kubectl  top node
NAME           CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
k8s-master01   109m         2%     1296Mi          33%       
k8s-master02   99m          2%     1124Mi          29%       
k8s-master03   104m         2%     1082Mi          28%       
k8s-node01     55m          1%     761Mi           19%       
k8s-node02     53m          1%     663Mi           17%

Dashboard部署

​ Dashboard用于展示集群中的各类资源，同时也可以通过Dashboard实时查看Pod的日志和在容器中执行一些命令等。

安装指定版本dashboard

cd /root/k8s-ha-install/dashboard/

[root@k8s-master01 dashboard]# kubectl  create -f .
serviceaccount/admin-user created
clusterrolebinding.rbac.authorization.k8s.io/admin-user created
namespace/kubernetes-dashboard created
serviceaccount/kubernetes-dashboard created
service/kubernetes-dashboard created
secret/kubernetes-dashboard-certs created
secret/kubernetes-dashboard-csrf created
secret/kubernetes-dashboard-key-holder created
configmap/kubernetes-dashboard-settings created
role.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrole.rbac.authorization.k8s.io/kubernetes-dashboard created
rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
deployment.apps/kubernetes-dashboard created
service/dashboard-metrics-scraper created
deployment.apps/dashboard-metrics-scraper created

安装最新版

官方GitHub地址：https://github.com/kubernetes/dashboard

可以在官方dashboard查看到最新版dashboard

image-20210617193019062

kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.3/aio/deploy/recommended.yaml

创建管理员用户vim admin.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding 
metadata: 
  name: admin-user
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kube-system

kubectl apply -f admin.yaml -n kube-system

登录dashboard

在谷歌浏览器（Chrome）启动文件中加入启动参数，用于解决无法访问Dashboard的问题

--test-type --ignore-certificate-errors

image-20210617193221846

更改dashboard的svc为NodePort：

kubectl edit svc kubernetes-dashboard -n kubernetes-dashboard

image-20210617193256571

将ClusterIP更改为NodePort（如果已经为NodePort忽略此步骤）：

查看端口号：

kubectl get svc kubernetes-dashboard -n kubernetes-dashboard

image-20210617193320328

根据自己的实例端口号，通过任意安装了kube-proxy的宿主机或者VIP的IP+端口即可访问到dashboard：

访问Dashboard：https://192.168.101.236:18282（请更改18282为自己的端口），选择登录方式为令牌（即token方式）

image-20210617193344927

查看token值：

[root@k8s-master01 1.1.1]# kubectl -n kube-system describe secret (kubectl -n kube-system get secret | grep admin-user | awk '{print1}')
Name:         admin-user-token-r4vcp
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: admin-user
              kubernetes.io/service-account.uid: 2112796c-1c9e-11e9-91ab-000c298bf023

Type:  kubernetes.io/service-account-token

Data
====
ca.crt:     1025 bytes
namespace:  11 bytes
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi11c2VyLXRva2VuLXI0dmNwIiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZXJ2aWNlLWFjY291bnQubmFtZSI6ImFkbWluLXVzZXIiLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC51aWQiOiIyMTEyNzk2Yy0xYzllLTExZTktOTFhYi0wMDBjMjk4YmYwMjMiLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6a3ViZS1zeXN0ZW06YWRtaW4tdXNlciJ9.bWYmwgRb-90ydQmyjkbjJjFt8CdO8u6zxVZh-19rdlL_T-n35nKyQIN7hCtNAt46u6gfJ5XXefC9HsGNBHtvo_Ve6oF7EXhU772aLAbXWkU1xOwQTQynixaypbRIas_kiO2MHHxXfeeL_yYZRrgtatsDBxcBRg-nUQv4TahzaGSyK42E_4YGpLa3X3Jc4t1z0SQXge7lrwlj8ysmqgO4ndlFjwPfvg0eoYqu9Qsc5Q7tazzFf9mVKMmcS1ppPutdyqNYWL62P1prw_wclP0TezW1CsypjWSVT4AuJU8YmH8nTNR1EXn8mJURLSjINv6YbZpnhBIPgUGk1JYVLcn47w

将token值输入到令牌后，单击登录即可访问Dashboard

image-20210617193428102

一些必须的配置更改

​ 将Kube-proxy改为ipvs模式，因为在初始化集群的时候注释了ipvs配置，所以需要自行修改一下：

在master01节点执行

kubectl edit cm kube-proxy -n kube-system
mode: “ipvs”

更新Kube-Proxy的Pod：

kubectl patch daemonset kube-proxy -p "{\"spec\":{\"template\":{\"metadata\":{\"annotations\":{\"date\":\"`date +'%s'`\"}}}}}" -n kube-system

验证Kube-Proxy模式

[root@k8s-master01 1.1.1]# curl 127.0.0.1:10249/proxyMode
ipvs

注意事项

注意：kubeadm安装的集群，证书有效期默认是一年。master节点的kube-apiserver、kube-scheduler、kube-controller-manager、etcd都是以容器运行的。可以通过kubectl get po -n kube-system查看。

启动和二进制不同的是，

kubelet的配置文件在/etc/sysconfig/kubelet和/var/lib/kubelet/config.yaml

其他组件的配置文件在/etc/kubernetes/manifests目录下，比如kube-apiserver.yaml，该yaml文件更改后，kubelet会自动刷新配置，也就是会重启pod。不能再次创建该文件

Kubeadm安装后，master节点默认不允许部署pod，可以通过以下方式打开：

查看Taints：

[root@k8s-master01 ~]# kubectl  describe node -l node-role.kubernetes.io/master=  | grep Taints
Taints:             node-role.kubernetes.io/master:NoSchedule
Taints:             node-role.kubernetes.io/master:NoSchedule
Taints:             node-role.kubernetes.io/master:NoSchedule

删除Taint：

[root@k8s-master01 ~]# kubectl  taint node  -l node-role.kubernetes.io/master node-role.kubernetes.io/master:NoSchedule-
node/k8s-master01 untainted
node/k8s-master02 untainted
node/k8s-master03 untainted
[root@k8s-master01 ~]# kubectl  describe node -l node-role.kubernetes.io/master=  | grep Taints
Taints:             <none>
Taints:             <none>
Taints:             <none>
Work Blog » 16_CKA_Kubeadm高可用安装k8s集群
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