【Kubernetes】Kubernetes之Kubeadm部署

---

一、Kubeadm 部署

集群服务器主机名	服务器IP地址	集群服务器部署的服务
master（2C/4G，cpu核心数要求大于2）	192.168.145.15	docker、kubeadm、kubelet、kubectl、flannel
node01（2C/2G）	192.168.145.30	docker、kubeadm、kubelet、kubectl、flannel
node02（2C/2G）	192.168.145.45	docker、kubeadm、kubelet、kubectl、flannel

1、在所有节点上安装Docker和kubeadm
2、部署Kubernetes Master
3、部署容器网络插件
4、部署 Kubernetes Node，将节点加入Kubernetes集群中

1. 环境准备

#所有节点，关闭防火墙规则，关闭selinux，关闭swap交换
systemctl stop firewalld
systemctl disable firewalld
setenforce 0
sed -i 's/enforcing/disabled/' /etc/selinux/config
iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X
swapoff -a								#交换分区必须要关闭
sed -ri 's/.*swap.*/#&/' /etc/fstab		#永久关闭swap分区，&符号在sed命令中代表上次匹配的结果
#加载 ip_vs 模块
for i in $(ls /usr/lib/modules/$(uname -r)/kernel/net/netfilter/ipvs|grep -o "^[^.]*");do echo $i; /sbin/modinfo -F filename $i >/dev/null 2>&1 && /sbin/modprobe $i;done

#修改主机名
hostnamectl set-hostname master01
hostnamectl set-hostname node01
hostnamectl set-hostname node02

#所有节点修改hosts文件
vim /etc/hosts
192.168.145.15 master01
192.168.145.30 node01
192.168.145.45 node02

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#调整内核参数
cat > /etc/sysctl.d/kubernetes.conf << EOF
#开启网桥模式，可将网桥的流量传递给iptables链
net.bridge.bridge-nf-call-ip6tables=1
net.bridge.bridge-nf-call-iptables=1
#关闭ipv6协议
net.ipv6.conf.all.disable_ipv6=1
net.ipv4.ip_forward=1
EOF

#生效参数
sysctl --system

2. 所有节点安装 docker

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 
yum install -y docker-ce docker-ce-cli containerd.io

cd /etc/docker
cat > /etc/docker/daemon.json <<EOF
{
  "registry-mirrors": ["https://00ub0bmk.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "500m", "max-file": "3"
  }
}
EOF
#使用Systemd管理的Cgroup来进行资源控制与管理，因为相对Cgroupfs而言，Systemd限制CPU、内存等资源更加简单和成熟稳定。
#日志使用json-file格式类型存储，大小为100M，保存在/var/log/containers目录下，方便ELK等日志系统收集和管理日志。

systemctl daemon-reload				#重载配置文件
systemctl start docker.service		#启动 docker 服务
systemctl enable docker.service		#将 docker 服务设置开机自启

docker info | grep "Cgroup Driver"	#查看 dokcer 的配置信息
Cgroup Driver: systemd

3. 所有节点安装 kubeadm，kubelet 和 kubectl

#定义kubernetes源
cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

yum install -y kubelet-1.20.15 kubeadm-1.20.15 kubectl-1.20.15

#开机自启kubelet
systemctl enable kubelet.service
#K8S通过kubeadm安装出来以后都是以Pod方式存在，即底层是以容器方式运行，所以kubelet必须设置开机自启

4. 部署 K8S 集群

4.1 配置 master01 节点

#查看初始化需要的镜像
kubeadm config images list --kubernetes-version 1.20.15

#初始化kubeadm
kubeadm config print init-defaults > /opt/kubeadm-config.yaml

cd /opt/
vim kubeadm-config.yaml
......
11 localAPIEndpoint:
12   advertiseAddress: 192.168.145.15		#指定master节点的IP地址
13   bindPort: 6443
......
32 imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers          #指定拉取镜像的仓库，默认是k8s.gcr.io
33 kind: ClusterConfiguration
34 kubernetesVersion: v1.20.15				#指定kubernetes版本号
35 networking:
36   dnsDomain: cluster.local
37   podSubnet: 10.244.0.0/16				#指定pod网段，10.244.0.0/16用于匹配flannel默认网段
38   serviceSubnet: 10.96.0.0/16			#指定service网段
39 scheduler: {}
#末尾再添加以下内容
--- 
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs									#把默认的kube-proxy调度方式改为ipvs模式

#在线拉取镜像
kubeadm config images pull --config /opt/kubeadm-config.yaml
#查看镜像
docker images

#初始化 master
kubeadm init --config=/opt/kubeadm-config.yaml --upload-certs | tee kubeadm-init.log
#--upload-certs 参数可以在后续执行加入节点时自动分发证书文件
#tee kubeadm-init.log 用以输出日志

#查看 kubeadm-init 日志
less kubeadm-init.log

#kubernetes配置文件目录
ls /etc/kubernetes/

#存放ca等证书和密码的目录
ls /etc/kubernetes/pki

#设定kubectl
kubectl需经由API server认证及授权后方能执行相应的管理操作，kubeadm 部署的集群为其生成了一个具有管理员权限的认证配置文件 /etc/kubernetes/admin.conf，它可由 kubectl 通过默认的 “$HOME/.kube/config” 的路径进行加载。

mkdir -p $HOME/.kube									#在家目录中新键 .kube 目录
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config		#将自动生成的 admin.conf 文件复制到家目录中 ./kube 目录
chown $(id -u):$(id -g) $HOME/.kube/config				#给 config 文件授权

#部署网络插件flannel
#上传 flannel 镜像 flannel.tar 和网络插件 cni-plugins-linux-amd64-v0.8.6.tgz 到 /opt 目录，master节点上传 kube-flannel.yml 文件
cd /opt/
unzip flannel-v0.21.5.zip

docker load -i flannel.tar
docker load -i flannel-cni-plugin.tar

)

mv /opt/cni /opt/cni_bak
mkdir -p /opt/cni/bin
tar xf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin

#在 master 节点创建 flannel 资源
kubectl apply -f kube-flannel.yml 

#在master节点查看节点状态
kubectl get nodes

kubectl get pods -A
NAMESPACE      NAME                               READY   STATUS    RESTARTS   AGE
kube-flannel   kube-flannel-ds-xffxg              1/1     Running   0          24s
kube-system    coredns-54d67798b7-7jjll           1/1     Running   0          9m49s
kube-system    coredns-54d67798b7-txdlc           1/1     Running   0          9m49s
kube-system    etcd-master01                      1/1     Running   0          9m58s
kube-system    kube-apiserver-master01            1/1     Running   0          9m58s
kube-system    kube-controller-manager-master01   1/1     Running   0          9m58s
kube-system    kube-proxy-ll5bh                   1/1     Running   0          9m49s
kube-system    kube-scheduler-master01            1/1     Running   0          9m58s

4.2 配置 node 节点

#将 master01 节点上的 flannel 相关文件传送到所有 node 节点
scp flannel*tar node01:/opt		#在master操作
scp flannel*tar node02:/opt		#在master操作

#将node节点根据根据kubeadm init初始化的提示信息快速的加入到K8S集群当中
kubeadm join 192.168.145.15:6443 --token abcdef.0123456789abcdef \
>     --discovery-token-ca-cert-hash sha256:508d252e11aadcbe12da889eb90038a6f72d8aa4922f166a1fa4f765bfe723ce

#部署网络插件flannel
cd /opt/
docker load -i flannel.tar
docker load -i flannel-cni-plugin.tar

#在master节点查看节点状态
kubectl get nodes

kubectl get pods -A

二、Kubeadm 高可用部署

#注意事项：
master节点cpu核心数要求大于2
● 最新的版本不一定好，但相对于旧版本，核心功能稳定，但新增功能、接口相对不稳
● 学会一个版本的 高可用部署，其他版本操作都差不多
● 宿主机尽量升级到CentOS 7.9
● 内核kernel升级到 4.19+ 这种稳定的内核
● 部署k8s版本时，尽量找 1.xx.5 这种大于5的小版本（这种一般是比较稳定的版本）

集群服务器主机名	服务器IP地址	集群服务器部署的服务
master01（2C/4G，cpu核心数要求大于2）	192.168.145.15	docker、kubeadm、kubelet、kubectl、flannel
master02（2C/4G，cpu核心数要求大于2）	192.168.145.30	docker、kubeadm、kubelet、kubectl、flannel
master03（2C/4G，cpu核心数要求大于2）	192.168.145.45	docker、kubeadm、kubelet、kubectl、flannel
node01（2C/2G）	192.168.145.60	docker、kubeadm、kubelet、kubectl、flannel
node02（2C/2G）	192.168.145.75	docker、kubeadm、kubelet、kubectl、flannel

1. 环境准备

#所有节点，关闭防火墙规则，关闭selinux，关闭swap交换
systemctl stop firewalld
systemctl disable firewalld
setenforce 0
sed -i 's/enforcing/disabled/' /etc/selinux/config
iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X
swapoff -a
sed -ri 's/.*swap.*/#&/' /etc/fstab

#修改主机名
hostnamectl set-hostname master01
hostnamectl set-hostname master02
hostnamectl set-hostname master03
hostnamectl set-hostname node01
hostnamectl set-hostname node02


#所有节点修改hosts文件
vim /etc/hosts
192.168.145.15 master01
192.168.145.30 master02
192.168.145.45 master03
192.168.145.60 node01
192.168.145.75 node02

#所有节点时间同步
yum -y install ntpdate
ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
echo 'Asia/Shanghai' >/etc/timezone
ntpdate time2.aliyun.com

systemctl enable --now crond

crontab -e
*/30 * * * * /usr/sbin/ntpdate time2.aliyun.com

#所有节点实现Linux的资源限制
vim /etc/security/limits.conf
* soft nofile 65536
* hard nofile 131072
* soft nproc 65535
* hard nproc 655350
* soft memlock unlimited
* hard memlock unlimited

#调整内核参数
cat > /etc/sysctl.d/k8s.conf <<EOF
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

#生效参数
sysctl --system  


#加载 ip_vs 模块
for i in $(ls /usr/lib/modules/$(uname -r)/kernel/net/netfilter/ipvs|grep -o "^[^.]*");do echo $i; /sbin/modinfo -F filename $i >/dev/null 2>&1 && /sbin/modprobe $i;done

2. 所有节点安装 docker

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 
yum install -y docker-ce docker-ce-cli containerd.io

cd /etc/docker
cat > /etc/docker/daemon.json <<EOF
{
  "registry-mirrors": ["https://00ub0bmk.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "500m", "max-file": "3"
  }
}
EOF

systemctl daemon-reload
systemctl restart docker.service
systemctl enable docker.service 

2. 所有节点安装kubeadm，kubelet和kubectl

#定义kubernetes源
cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

yum install -y kubelet-1.20.15 kubeadm-1.20.15 kubectl-1.20.15

#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

#开机自启kubelet
systemctl enable --now kubelet

3. 高可用组件安装、配置

#所有 master 节点部署 Haproxy
yum -y install haproxy keepalived

cat > /etc/haproxy/haproxy.cfg << EOF
global
    log         127.0.0.1 local0 info
    log         127.0.0.1 local1 warning
    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user        haproxy
    group       haproxy
    daemon
    stats socket /var/lib/haproxy/stats

defaults
    mode                    tcp
    log                     global
    option                  tcplog
    option                  dontlognull
    option                  redispatch
    retries                 3
    timeout queue           1m
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    timeout check           10s
    maxconn                 3000

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

frontend k8s-master
    bind *:16443
    mode tcp
    option tcplog
    default_backend k8s-master

backend k8s-master
    mode tcp
    option tcplog
    option tcp-check
    balance roundrobin
    server k8s-master1 192.168.145.15:6443  check inter 10000 fall 2 rise 2 weight 1
    server k8s-master2 192.168.145.30:6443  check inter 10000 fall 2 rise 2 weight 1
    server k8s-master3 192.168.145.45:6443  check inter 10000 fall 2 rise 2 weight 1
EOF

#所有 master 节点部署 keepalived
cd /etc/keepalived/
vim keepalived.conf
! Configuration File for keepalived
global_defs {
    router_id LVS_HA1			#路由标识符，每个节点配置不同
}

vrrp_script chk_haproxy {
    script "/etc/keepalived/check_haproxy.sh"
    interval 2
    weight 2
}

vrrp_instance VI_1 {
    state MASTER				#本机实例状态，MASTER/BACKUP，备机配置文件中设置BACKUP
    interface ens33
    virtual_router_id 51
    priority 100				#本机初始权重，备机设置小于主机的值
    advert_int 1
    virtual_ipaddress {
        192.168.145.100          #设置VIP地址
    }
    track_script {
        chk_haproxy
    }
}

vim check_haproxy.sh
#!/bin/bash
if ! killall -0 haproxy; then
    systemctl stop keepalived
fi


systemctl enable --now haproxy
systemctl enable --now keepalived

4. 部署 K8S 集群

#在 master01 节点上设置集群初始化配置文件
kubeadm config print init-defaults > /opt/kubeadm-config.yaml

cd /opt/
vim kubeadm-config.yaml
......
11 localAPIEndpoint:
12   advertiseAddress: 192.168.145.15		#指定当前master节点的IP地址
13   bindPort: 6443

21 apiServer:
22   certSANs:								#在apiServer属性下面添加一个certsSANs的列表，添加所有master节点的IP地址和集群VIP地址
23   - 192.168.145.100
24   - 192.168.145.15
25   - 192.168.145.30
26   - 192.168.145.45

30 clusterName: kubernetes
31 controlPlaneEndpoint: "192.168.145.100:6443"		#指定集群VIP地址
32 controllerManager: {}

38 imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers			#指定镜像下载地址
39 kind: ClusterConfiguration
40 kubernetesVersion: v1.20.15				#指定kubernetes版本号
41 networking:
42   dnsDomain: cluster.local
43   podSubnet: "10.244.0.0/16"				#指定pod网段，10.244.0.0/16用于匹配flannel默认网段
44   serviceSubnet: 10.96.0.0/16			#指定service网段
45 scheduler: {}
#末尾再添加以下内容
--- 
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs									#把默认的kube-proxy调度方式改为ipvs模式


#更新集群初始化配置文件
kubeadm config migrate --old-config kubeadm-config.yaml --new-config new.yaml

#所有节点拉取镜像
#拷贝yaml配置文件给其他主机，通过配置文件进行拉取镜像
for i in master02 master03 node01 node02; do scp /opt/new.yaml $i:/opt/; done

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

#master01 节点进行初始化
kubeadm init --config new.yaml --upload-certs | tee kubeadm-init.log
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.conf $HOME/.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:
#master节点加入使用的命令，记录！
  kubeadm join 192.168.145.100:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:63df6e626b225f6b60112bbc592d0ff69c1ae2e7869c9b41f142e4776df71d53 \
    --control-plane --certificate-key 0aad75a1c7f178755e4776e474e12616ab88086c93984ba311a465df1999d193

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:
#node节点加入使用的命令。记录！
kubeadm join 192.168.145.100:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:63df6e626b225f6b60112bbc592d0ff69c1ae2e7869c9b41f142e4776df71d53 

#将其他节点加入集群中

#将mater节点加入集群中
kubeadm join 192.168.145.100:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:63df6e626b225f6b60112bbc592d0ff69c1ae2e7869c9b41f142e4776df71d53 \
    --control-plane --certificate-key 0aad75a1c7f178755e4776e474e12616ab88086c93984ba311a465df1999d193

#将node节点加入集群中
kubeadm join 192.168.145.100:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:63df6e626b225f6b60112bbc592d0ff69c1ae2e7869c9b41f142e4776df71d53 

#若初始化失败，进行的操作
kubeadm reset -f
ipvsadm --clear 
rm -rf ~/.kube
再次进行初始化

#master01 节点进行环境配置
#配置 kubectl
mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config

#修改controller-manager和scheduler配置文件
vim /etc/kubernetes/manifests/kube-scheduler.yaml 
vim /etc/kubernetes/manifests/kube-controller-manager.yaml
......
    #- --port=0					#搜索port=0，把这一行注释掉

systemctl restart kubelet 

#部署网络插件flannel
所有节点上传 flannel 镜像 flannel.tar 和网络插件 cni-plugins-linux-amd64-v0.8.6.tgz 到 /opt 目录，master节点上传 kube-flannel.yml 文件
cd /opt
unzip flannel-v0.21.5.zip
docker load -i flannel.tar
docker load -i flannel-cni-plugin.tar

mv /opt/cni /opt/cni_bak
mkdir -p /opt/cni/bin
tar xf cni-plugins-linux-amd64-v1.3.0.tgz /opt/cni/bin

kubectl apply -f kube-flannel.yml

#其他节点操作
#配置 kubectl
mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config

kubectl apply -f kube-flannel.yml 

#在 master01 查看集群信息
kubectl get nodes

kubectl get pod -n kube-system 

总结

kubeadm 部署过程

1）所有节点进行初始化,安装docker引擎和kubeadm kubelet kubectl
2）生成集群初始化配置文件并进行修改
3）使用kubeadm init根据初始化配置文件生成K8S的master控制管理节点
4）安装CNI网络插件（flannel、calico等）
5）在其他节点使用kubeadm join将节点以node

kubeadm 部署的K8S集群更新证书

1）备份老证书和kubeconfig配置文件
mkdir /etc/kubernetes.bak
cp -r /etc/kubernetes/pki/ /etc/kubernetes.bak
cp /etc/kubernetes/*.conf /etc/kubernetes.bak

2）重新生成证书
kubeadm alpha certs renew all --config=kubeadm.yaml

3）重新生成kubeconfig配置文件
kubeadm init phase kubeconfig all --config kubeadm.yaml

4）重启kubelet和其他K8S组件的Pod容器
systemctl restart kubelet

mv /etc/kubernetes/manifests  /tmp
mv /tmp/*.yaml  /etc/kubernetes/manifests