使用kubeadm部署 kubernetes v1.23.1 高可用集群

一、环境准备

使用服务器 Centos 8.4 镜像，默认操作系统版本 4.18.0-305.3.1.el8.x86_64。

注意：由于云服务器，无法使用VIP，没有办法使用keepalive+nginx使用三节点VIP，这里在kubeadm init初始化配置文件中指定了一个master01节点的IP。

主机名	IP	操作系统版本	安装组件
etcd01	192.168.79.10	4.18.0-305.3.1.el8.x86_64	https://github.com/etcd-io/etcd/releases/download/v3.5.1/etcd-v3.5.1-linux-amd64.tar.gz
etcd02	192.168.79.11	4.18.0-305.3.1.el8.x86_64
etcd03	192.168.79.12	4.18.0-305.3.1.el8.x86_64
master01	192.168.86.40	4.18.0-305.3.1.el8.x86_64	docker-ce/kubeadm/kubelet/kubectl
master02	192.168.86.41	4.18.0-305.3.1.el8.x86_64
master03	192.168.86.42	4.18.0-305.3.1.el8.x86_64
node01	192.168.86.43	4.18.0-305.3.1.el8.x86_64	docker-ce/kubeadm/kubelet
node02	192.168.79.13	4.18.0-305.3.1.el8.x86_64

二、服务器初始化

所有服务器进行初始化，只需要对master和node节点就可以，脚本内容在Centos 8 已经得到验证。

1、主要做了以下操作，安装一些必要依赖包、禁用ipv6、启用时间同步、加载ipvs模块、修改内核参数、禁用swap、关闭防火墙等；

[root@node01 k8s_install]# cat 1_init_all_host.sh
#!/bin/bash

# 1. install common tools,these commands are not required.
source /etc/profile
yum -y install chrony bridge-utils chrony ipvsadm ipset sysstat conntrack libseccomp wget tcpdump screen vim nfs-utils bind-utils wget socat telnet sshpass net-tools sysstat lrzsz yum-utils device-mapper-persistent-data lvm2 tree nc lsof strace nmon iptraf iftop rpcbind mlocate

# 2. disable IPv6
if [ $(cat /etc/default/grub |grep 'ipv6.disable=1' |grep GRUB_CMDLINE_LINUX|wc -l) -eq 0 ];then
    sed -i 's/GRUB_CMDLINE_LINUX="/GRUB_CMDLINE_LINUX="ipv6.disable=1 /' /etc/default/grub
    /usr/sbin/grub2-mkconfig -o /boot/grub2/grub.cfg
fi

# 3. disable NetworkManager，centos8 use NetworkManager，otherwise network reboot failed.
# systemctl stop NetworkManager
# systemctl disable NetworkManager

# 4. enable chronyd service
systemctl enable chronyd.service
systemctl start chronyd.service

# 5. add bridge-nf-call-ip6tables ,notice: You may need to run '/usr/sbin/modprobe br_netfilter' this commond after reboot.
cat > /etc/rc.sysinit << EOF
#!/bin/bash
for file in /etc/sysconfig/modules/*.modules ; do
[ -x $file ] && $file
done
EOF

cat > /etc/sysconfig/modules/br_netfilter.modules << EOF
modprobe br_netfilter
EOF

cat > /etc/sysconfig/modules/ipvs.modules <>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv6.conf.default.disable_ipv6=1" |wc -l) -eq 0 ] && echo "net.ipv6.conf.default.disable_ipv6=1" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv6.conf.lo.disable_ipv6=1" |wc -l) -eq 0 ] && echo "net.ipv6.conf.lo.disable_ipv6=1" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.neigh.default.gc_stale_time=120" |wc -l) -eq 0 ] && echo "net.ipv4.neigh.default.gc_stale_time=120" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.conf.all.rp_filter=0" |wc -l) -eq 0 ] && echo "net.ipv4.conf.all.rp_filter=0" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "fs.inotify.max_user_instances=8192" |wc -l) -eq 0 ] && echo "fs.inotify.max_user_instances=8192" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "fs.inotify.max_user_watches=1048576" |wc -l) -eq 0 ] && echo "fs.inotify.max_user_watches=1048576" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.ip_forward=1" |wc -l) -eq 0 ] && echo "net.ipv4.ip_forward=1" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.bridge.bridge-nf-call-iptables=1" |wc -l) -eq 0 ] && echo "net.bridge.bridge-nf-call-iptables=1" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.bridge.bridge-nf-call-ip6tables=1" |wc -l) -eq 0 ] && echo "net.bridge.bridge-nf-call-ip6tables=1" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.bridge.bridge-nf-call-arptables=1" |wc -l) -eq 0 ] && echo "net.bridge.bridge-nf-call-arptables=1" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.conf.default.rp_filter=0" |wc -l) -eq 0 ] && echo "net.ipv4.conf.default.rp_filter=0" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.conf.default.arp_announce=2" |wc -l) -eq 0 ] && echo "net.ipv4.conf.default.arp_announce=2" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.conf.lo.arp_announce=2" |wc -l) -eq 0 ] && echo "net.ipv4.conf.lo.arp_announce=2" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.conf.all.arp_announce=2" |wc -l) -eq 0 ] && echo "net.ipv4.conf.all.arp_announce=2" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.tcp_max_tw_buckets=5000" |wc -l) -eq 0 ] && echo "net.ipv4.tcp_max_tw_buckets=5000" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.tcp_syncookies=1" |wc -l) -eq 0 ] && echo "net.ipv4.tcp_syncookies=1" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.tcp_max_syn_backlog=1024" |wc -l) -eq 0 ] && echo "net.ipv4.tcp_max_syn_backlog=1024" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.ipv4.tcp_synack_retries=2" |wc -l) -eq 0 ] && echo "net.ipv4.tcp_synack_retries=2" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "fs.may_detach_mounts=1" |wc -l) -eq 0 ] && echo "fs.may_detach_mounts=1" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "vm.overcommit_memory=1" |wc -l) -eq 0 ] && echo "vm.overcommit_memory=1" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "vm.panic_on_oom=0" |wc -l) -eq 0 ] && echo "vm.panic_on_oom=0" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "vm.swappiness=0" |wc -l) -eq 0 ] && echo "vm.swappiness=0" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "fs.inotify.max_user_watches=89100" |wc -l) -eq 0 ] && echo "fs.inotify.max_user_watches=89100" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "fs.file-max=52706963" |wc -l) -eq 0 ] && echo "fs.file-max=52706963" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "fs.nr_open=52706963" |wc -l) -eq 0 ] && echo "fs.nr_open=52706963" >>/etc/sysctl.conf
[ $(cat /etc/sysctl.conf | grep "net.netfilter.nf_conntrack_max=2310720" |wc -l) -eq 0 ] && echo "net.netfilter.nf_conntrack_max=2310720" >>/etc/sysctl.conf

/usr/sbin/sysctl -p


# 7. modify limit file
[ $(cat /etc/security/limits.conf|grep '* soft nproc 10240000'|wc -l) -eq 0 ]&&echo '* soft nproc 10240000' >>/etc/security/limits.conf
[ $(cat /etc/security/limits.conf|grep '* hard nproc 10240000'|wc -l) -eq 0 ]&&echo '* hard nproc 10240000' >>/etc/security/limits.conf
[ $(cat /etc/security/limits.conf|grep '* soft nofile 10240000'|wc -l) -eq 0 ]&&echo '* soft nofile 10240000' >>/etc/security/limits.conf
[ $(cat /etc/security/limits.conf|grep '* hard nofile 10240000'|wc -l) -eq 0 ]&&echo '* hard nofile 10240000' >>/etc/security/limits.conf

# 8. disable selinux
sed -i '/SELINUX=/s/enforcing/disabled/' /etc/selinux/config

# 9. Close the swap partition
/usr/sbin/swapoff -a
yes | cp /etc/fstab /etc/fstab_bak
cat /etc/fstab_bak |grep -v swap > /etc/fstab

# 10. disable firewalld
systemctl stop firewalld
systemctl disable firewalld

# 11. reset iptables
yum install -y iptables-services
/usr/sbin/iptables -P FORWARD ACCEPT
/usr/sbin/iptables -X
/usr/sbin/iptables -Z
/usr/sbin/iptables -F -t nat
/usr/sbin/iptables -X -t nat

reboot
[root@node01 k8s_install]#

2、修改主机名和hosts

[root@node01 k8s_install]# cat ip2
192.168.79.10 etcd01
192.168.79.11 etcd02
192.168.79.12 etcd03
192.168.79.13 node02
192.168.86.40 master01
192.168.86.41 master02
192.168.86.42 master03
192.168.86.43 node01
[root@node01 k8s_install]# cat 2_modify_hosts_and_hostname.sh
#!/bin/bash
DIR=`pwd`
cd $DIR
cat ip2 |gawk '{print $2,$1}'>hosts_temp
exec <./ip2
while read A B
do
  scp ${DIR}/hosts_temp $A:/root/
  ssh -n $A "hostnamectl set-hostname $B && cat /root/hosts_temp >>/etc/hosts && rm -rf hosts_temp"
done

rm -rf hosts_temp
[root@node01 k8s_install]#

三、安装etcd

1、生成CA根证书，由于使用TLS安全认证功能，需要为etcd访问ca证书和私钥，证书签发。

[root@node01 k8s_install]# cat 3_ca_root.sh
#!/bin/bash

# 1. download cfssl related files.

while true;
do
        echo "Download cfssl, please wait a monment." &&\
        curl -L -C - -O https://github.com/cloudflare/cfssl/releases/download/v1.6.1/cfssl_1.6.1_linux_amd64 && \
        curl -L -C - -O https://github.com/cloudflare/cfssl/releases/download/v1.6.1/cfssljson_1.6.1_linux_amd64 && \
        curl -L -C - -O https://github.com/cloudflare/cfssl/releases/download/v1.6.1/cfssl-certinfo_1.6.1_linux_amd64
        if [ $? -eq 0 ];then
                echo "cfssl download success."
                break
        else
                echo "cfssl download failed."
                break
        fi
done

# 2. Create a binary dirctory to store kubernetes related files.
if [ ! -d /usr/kubernetes/bin/ ];then
        mkdir -p /usr/kubernetes/bin/
fi

# 3. copy binary files to before create a binary dirctory.
mv cfssl_1.6.1_linux_amd64 /usr/kubernetes/bin/cfssl
mv cfssljson_1.6.1_linux_amd64 /usr/kubernetes/bin/cfssljson
mv cfssl-certinfo_1.6.1_linux_amd64 /usr/kubernetes/bin/cfssl-certinfo
chmod +x /usr/kubernetes/bin/{cfssl,cfssljson,cfssl-certinfo}

# 4. add environment variables
[ $(cat /etc/profile|grep 'PATH=/usr/kubernetes/bin'|wc -l ) -eq 0 ] && echo 'PATH=/usr/kubernetes/bin:$PATH' >>/etc/profile && source /etc/profile || source /etc/profile

# 5. create a CA certificate directory and access this directory
CA_SSL=/etc/kubernetes/ssl/ca
[ ! -d ${CA_SSL} ] && mkdir -p ${CA_SSL}
cd $CA_SSL

## cfssl print-defaults config > config.json
## cfssl print-defaults csr > csr.json

cat > ${CA_SSL}/ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF

cat > ${CA_SSL}/ca-csr.json <

2、使用私有CA为ETCD签发证书和私钥

[root@node01 k8s_install]# cat 4_ca_etcd.sh
#!/bin/bash

# 2. create csr file.
source /etc/profile

ETCD_SSL="/etc/kubernetes/ssl/etcd/"

[ ! -d ${ETCD_SSL} ] && mkdir ${ETCD_SSL}
cat >$ETCD_SSL/etcd-csr.json << EOF
{
    "CN": "etcd",
    "hosts": [
    "192.168.79.10",
    "192.168.79.11",
    "192.168.79.12",
    "192.168.79.13",
    "192.168.86.40",
    "192.168.86.41",
    "192.168.86.42",
    "192.168.86.43"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing",
           "O": "k8s",
           "OU": "System"
        }
    ]
}
EOF

# 3. Determine if the ca required file exits.
[ ! -f /etc/kubernetes/ssl/ca/ca.pem ] && echo "no ca.pem file." && exit 0
[ ! -f /etc/kubernetes/ssl/ca/ca-key.pem ] && echo "no ca-key.pem file" && exit 0
[ ! -f /etc/kubernetes/ssl/ca/ca-config.json ] && echo "no ca-config.json file" && exit 0

# 4. generate etcd private key and public key.
cd $ETCD_SSL
cfssl gencert -ca=/etc/kubernetes/ssl/ca/ca.pem \
  -ca-key=/etc/kubernetes/ssl/ca/ca-key.pem \
  -config=/etc/kubernetes/ssl/ca/ca-config.json \
  -profile=kubernetes etcd-csr.json | cfssljson -bare etcd

[ $? -eq 0 ] && echo "Etcd certificate and private key generated successfully." || echo "Etcd certificate and private key generation failed."
[root@node01 k8s_install]#

3、copy 数字证书到etcd服务器和master上面

[root@node01 k8s_install]# cat 5_scp_etcd_pem_key.sh
#!/bin/bash
# 1. etcd need these file
for i in `cat ip2|grep etcd|gawk '{print $1}'`
do
  scp -r /etc/kubernetes $i:/etc/
done

# 2. k8s master node need these file too.
for i in `cat ip2|grep -v etcd|gawk '{print $1}'`
do
        scp -r /etc/kubernetes $i:/etc/
done
[root@node01 k8s_install]#

4、etcd的三台机器分别执行此脚本，以下脚本为完成etcd的全部安装过程，注意下载etcd安装包时，可以提前下载好，因为国内网络，大家都懂的；

[root@node01 k8s_install]# cat 6_etcd_install.sh
#!/bin/bash

# 1. env info
source /etc/profile
declare -A dict

dict=(['etcd01']=192.168.79.10 ['etcd02']=192.168.79.11 ['etcd03']=192.168.79.12)
IP=`ip a |grep inet|grep -v 127.0.0.1|gawk -F/ '{print $1}'|gawk '{print $NF}'`

for key in $(echo ${!dict[*]})
do
    if [[ "$IP" == "${dict[$key]}" ]];then
        LOCALIP=$IP
        LOCAL_ETCD_NAME=$key
    fi
done

if [[ "$LOCALIP" == "" || "$LOCAL_ETCD_NAME" == "" ]];then
    echo "Get localhost IP failed." && exit 1
fi

# 2. download etcd source code and decompress.
CURRENT_DIR=`pwd`
cd $CURRENT_DIR
curl -L -C - -O https://github.com/etcd-io/etcd/releases/download/v3.5.1/etcd-v3.5.1-linux-amd64.tar.gz
( [ $? -eq 0 ] && echo "etcd source code download success." ) || ( echo "etcd source code download failed." && exit 1 )

/usr/bin/tar -zxf etcd-v3.5.1-linux-amd64.tar.gz
cp etcd-v3.5.1-linux-amd64/etc* /usr/local/bin/
#rm -rf etcd-v3.3.18-linux-amd64*

# 3. deploy etcd config and enable etcd.service.

ETCD_SSL="/etc/kubernetes/ssl/etcd/"
ETCD_SERVICE=/usr/lib/systemd/system/etcd.service

[ ! -d /data/etcd/ ] && mkdir -p /data/etcd/

# 3.1 create /etc/etcd/etcd.conf configure file.

ETCD_NAME="${LOCAL_ETCD_NAME}"
ETCD_DATA_DIR="/data/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://${LOCALIP}:2380"
ETCD_LISTEN_CLIENT_URLS="https://${LOCALIP}:2379"
ETCD_LISTEN_CLIENT_URLS2="http://127.0.0.1:2379"
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://${LOCALIP}:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://${LOCALIP}:2379"
ETCD_INITIAL_CLUSTER="etcd01=https://${dict['etcd01']}:2380,etcd02=https://${dict['etcd02']}:2380,etcd03=https://${dict['etcd03']}:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

# 3.2 create etcd.service
cat>$ETCD_SERVICE<

5、登录etcd服务器，进行etcd安装验证

[root@node01 k8s_install]# cat 6_check_etcd.sh
#!/bin/bash
declare -A dict
dict=(['etcd01']=192.168.79.10 ['etcd02']=192.168.79.11 ['etcd03']=192.168.79.12)

echo "==== check endpoint health ===="
cd /usr/local/bin
ETCDCTL_API=3 ./etcdctl -w table --cacert=/etc/kubernetes/ssl/ca/ca.pem \
--cert=/etc/kubernetes/ssl/etcd/etcd.pem \
--key=/etc/kubernetes/ssl/etcd/etcd-key.pem \
--endpoints="https://${dict['etcd01']}:2379,https://${dict['etcd02']}:2379,https://${dict['etcd03']}:2379" endpoint health

echo
echo
echo "==== check member list ===="
ETCDCTL_API=3 ./etcdctl -w table --cacert=/etc/kubernetes/ssl/ca/ca.pem \
--cert=/etc/kubernetes/ssl/etcd/etcd.pem \
--key=/etc/kubernetes/ssl/etcd/etcd-key.pem \
--endpoints="https://${dict['etcd01']}:2379,https://${dict['etcd02']}:2379,https://${dict['etcd03']}:2379" member list

echo
echo
echo "==== check endpoint status --cluster ===="
ETCDCTL_API=3 ./etcdctl -w table --cacert=/etc/kubernetes/ssl/ca/ca.pem \
--cert=/etc/kubernetes/ssl/etcd/etcd.pem \
--key=/etc/kubernetes/ssl/etcd/etcd-key.pem \
--endpoints="https://${dict['etcd01']}:2379,https://${dict['etcd02']}:2379,https://${dict['etcd03']}:2379" endpoint status --cluster

## delete etcd node
#ETCDCTL_API=3 ./etcdctl --cacert=/etc/kubernetes/ssl/ca/ca.pem \
#--cert=/etc/kubernetes/ssl/etcd/etcd.pem \
#--key=/etc/kubernetes/ssl/etcd/etcd-key.pem \
#--endpoints="https://${dict['etcd01']}:2379,https://${dict['etcd02']}:2379,https://${dict['etcd03']}:2379" member remove xxxxx

## add etcd node
#ETCDCTL_API=3 ./etcdctl --cacert=/etc/kubernetes/ssl/ca/ca.pem \
#--cert=/etc/kubernetes/ssl/etcd/etcd.pem \
#--key=/etc/kubernetes/ssl/etcd/etcd-key.pem \
#--endpoints="https://${dict['etcd01']}:2379,https://${dict['etcd02']}:2379,https://${dict['etcd03']}:2379" member add xxxxx

[root@node01 k8s_install]#

四、安装docker引擎

[root@node01 k8s_install]# cat 7_docker_install.sh
#!/bin/bash

# 1. install docker repo
for i in `cat ip2|grep -v etcd|gawk '{print $1}'`
do
  ssh $i "yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo &&yum makecache && yum -y install docker-ce"
done

# 2. repair daemon.json modify docker data-root.
cat>`pwd`/daemon.json<

五、安装kubernetes组件

1、配置kubernetes yum源

[root@node01 k8s_install]# cat 8_kubernetes.repo.sh
#!/bin/bash

cat >`pwd`/kubernetes.repo<

2、安装

[root@node01 k8s_install]# cat 9_k8s_common_install.sh
#!/bin/bash

# yum list kubelet --showduplicates | sort -r
# yum install -y kubelet-1.17.3

# install master node
for i in `cat ip2|grep master|gawk '{print $1}'`
do
  ssh $i "yum -y install kubelet kubeadm kubectl"
done

# install node
for i in `cat ip2|grep node|gawk '{print $1}'`
do
        ssh $i "yum -y install kubelet kubeadm"
done
[root@node01 k8s_install]#

3、配置kubelet并设置开机启动

#!/bin/bash
for i in `cat ip2|grep -v etcd|gawk '{print $1}'`
do
  ssh $i "echo 'KUBELET_EXTRA_ARGS="--fail-swap-on=false"' > /etc/sysconfig/kubelet"
  ssh $i "systemctl enable kubelet.service"
done

现在不用着急启动，使用kubeadm初始化或者加入集群时，会自动启动。

4、创建初始化配置文件，可以在此基础上面修改

# 生成默认配置文件
kubeadm config print init-defaults

# 可以根据组件生成
kubeadm config print init-defaults --component-configs KubeProxyConfiguration
kubeadm config print init-defaults --component-configs KubeletConfiguration

这里我们的默认配置文件如下，使用外部etcd的方式，还有一个注意点，修改pod网段及kubeproxy运行模式，把此文件copy到master01节点上面运行，注意还需要把etcd的证书copy到master节点；

[root@master01 ~]# cat kubeadm_init.yaml
apiVersion: kubeadm.k8s.io/v1beta3
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 100.109.86.40
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  imagePullPolicy: IfNotPresent
  name: master01
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
  extraArgs:
    authorization-mode: "Node,RBAC"
    enable-admission-plugins: "NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeClaimResize,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota,Priority"
    runtime-config: api/all=true
  certSANs:
  - 10.96.0.1
  - 127.0.0.1
  - localhost
  - master01
  - master02
  - master03
  - 100.109.86.40
  - 100.109.86.41
  - 100.109.86.42
  - apiserver.k8s.local
  - kubernetes
  - kubernetes.default
  - kubernetes.default.svc
  - kubernetes.default.svc.cluster.local
  extraVolumes:
  - hostPath: /etc/localtime
    mountPath: /etc/localtime
    name: localtime
    readOnly: true
apiVersion: kubeadm.k8s.io/v1beta3
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager:
  extraArgs:
    bind-address: "0.0.0.0"
    experimental-cluster-signing-duration: 876000h
  extraVolumes:
  - hostPath: /etc/localtime
    mountPath: /etc/localtime
    name: localtime
    readOnly: true
dns:
  imageRepository: docker.io
  imageTag: 1.8.6
etcd:
  external:
    endpoints:
    - https://100.109.79.10:2379
    - https://100.109.79.11:2379
    - https://100.109.79.12:2379
    caFile: /etc/kubernetes/ssl/ca/ca.pem
    certFile: /etc/kubernetes/ssl/etcd/etcd.pem
    keyFile: /etc/kubernetes/ssl/etcd/etcd-key.pem
imageRepository: registry.aliyuncs.com/k8sxio
kind: ClusterConfiguration
kubernetesVersion: 1.23.1
networking:
  dnsDomain: cluster.local
  podSubnet: 172.30.0.0/16
  serviceSubnet: 10.96.0.0/12
controlPlaneEndpoint: 100.109.86.40:6443
scheduler:
  extraArgs:
    bind-address: "0.0.0.0"
  extraVolumes:
  - hostPath: /etc/localtime
    mountPath: /etc/localtime
    name: localtime
    readOnly: true
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
bindAddressHardFail: false
clientConnection:
  acceptContentTypes: ""
  burst: 0
  contentType: ""
  kubeconfig: /var/lib/kube-proxy/kubeconfig.conf
  qps: 0
clusterCIDR: ""
configSyncPeriod: 0s
conntrack:
  maxPerCore: null
  min: null
  tcpCloseWaitTimeout: null
  tcpEstablishedTimeout: null
detectLocalMode: ""
enableProfiling: false
healthzBindAddress: ""
hostnameOverride: ""
iptables:
  masqueradeAll: false
  masqueradeBit: null
  minSyncPeriod: 0s
  syncPeriod: 0s
ipvs:
  excludeCIDRs: null
  minSyncPeriod: 0s
  scheduler: ""
  strictARP: false
  syncPeriod: 0s
  tcpFinTimeout: 0s
  tcpTimeout: 0s
  udpTimeout: 0s
kind: KubeProxyConfiguration
metricsBindAddress: ""
mode: "ipvs"
nodePortAddresses: null
oomScoreAdj: null
portRange: ""
showHiddenMetricsForVersion: ""
udpIdleTimeout: 0s
winkernel:
  enableDSR: false
  networkName: ""
  sourceVip: ""
---
apiVersion: kubelet.config.k8s.io/v1beta1
cgroupDriver: systemd
kind: KubeletConfiguration
[root@master01 ~]#

5、查看依赖镜像，如果下载不到，自行想办法，国内网络你懂的。

[root@master01 ~]# kubeadm config images list --config=kubeadm_init.yaml
registry.aliyuncs.com/k8sxio/kube-apiserver:v1.23.1
registry.aliyuncs.com/k8sxio/kube-controller-manager:v1.23.1
registry.aliyuncs.com/k8sxio/kube-scheduler:v1.23.1
registry.aliyuncs.com/k8sxio/kube-proxy:v1.23.1
registry.aliyuncs.com/k8sxio/pause:3.6
docker.io/coredns:1.8.6
[root@master01 ~]#

6、初始化安装

kubeadm init --config=kubeadm_init.yaml

7、需要把master节点生成证书copy到其它master 节点

#!/bin/bash
# 在kubeadm init 的服务器上面运行；
for i in `cat /etc/hosts|grep -E "master02|master03"|gawk '{print $2}'`
do
  ssh $i "mkdir -p /etc/kubernetes/pki"
  scp /etc/kubernetes/pki/ca.* $i:/etc/kubernetes/pki/
  scp /etc/kubernetes/pki/sa.* $i:/etc/kubernetes/pki/
  scp /etc/kubernetes/pki/front-proxy-ca.* $i:/etc/kubernetes/pki/
  scp /etc/kubernetes/admin.conf $i:/etc/kubernetes/
done

8、把master02与master03加入到控制平面

kubeadm join 192.168.86.40:6443 --token abcdef.0123456789abcdef \
  --discovery-token-ca-cert-hash sha256:073ebe293b1072de412755791542fea2791abf25000038f55727880ccc8a71e4 \
  --control-plane --ignore-preflight-errors=Swap

9、在node01、node02上面运行

kubeadm join 192.168.86.40:6443 --token abcdef.0123456789abcdef \
  --discovery-token-ca-cert-hash sha256:073ebe293b1072de412755791542fea2791abf25000038f55727880ccc8a71e4 --ignore-preflight-errors=Swap

10、 master01节点

[root@master01 ~]# mkdir -p $HOME/.kube
[root@master01 ~]# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@master01 ~]# chown $(id -u):$(id -g) $HOME/.kube/config

六、部署CNI插件

1、前提准备

这里使用calico网络插件，下载链接，这个yaml文件中的image下载，在国内也很慢，需要你想办法解决此问题；

官网：https://projectcalico.docs.tigera.io/getting-started/kubernetes/self-managed-onprem/onpremises

下载地址：curl https://projectcalico.docs.tigera.io/manifests/calico.yaml -O

你可以根据你自定义的pod网段修改CALICO_IPV4POOL_CIDR对应的网段，默认是192.168.0.0/16，这里默认存储是etcd，还可以使用我们之前创建的etcd集群；由于这里没有做特别的修改，兼于文件太长，此配置不粘贴出来了。

- name: CALICO_IPV4POOL_CIDR
  value: "172.30.0.0/16"

2、应用

[root@master01 ~]# kubectl apply -f calico.yaml
configmap/calico-config unchanged
customresourcedefinition.apiextensions.k8s.io/bgpconfigurations.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/bgppeers.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/blockaffinities.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/clusterinformations.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/felixconfigurations.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/globalnetworkpolicies.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/globalnetworksets.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/hostendpoints.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/ipamblocks.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/ipamconfigs.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/ipamhandles.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/ippools.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/kubecontrollersconfigurations.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/networkpolicies.crd.projectcalico.org configured
customresourcedefinition.apiextensions.k8s.io/networksets.crd.projectcalico.org configured
clusterrole.rbac.authorization.k8s.io/calico-kube-controllers unchanged
clusterrolebinding.rbac.authorization.k8s.io/calico-kube-controllers unchanged
clusterrole.rbac.authorization.k8s.io/calico-node unchanged
clusterrolebinding.rbac.authorization.k8s.io/calico-node unchanged
daemonset.apps/calico-node configured
serviceaccount/calico-node unchanged
deployment.apps/calico-kube-controllers unchanged
serviceaccount/calico-kube-controllers unchanged
poddisruptionbudget.policy/calico-kube-controllers configured
[root@master01 ~]#

3、查看（注意镜像下载有问题，可以从阿里下载）

[root@master01 ~]# kubectl get pods -n kube-system|grep calico
calico-kube-controllers-7c8984549d-6jvwp 1/1 Running 0 5d20h
calico-node-5qbvf 1/1 Running 0 5d20h
calico-node-5v6f8 1/1 Running 0 5d20h
calico-node-nkc78 1/1 Running 0 5d20h
calico-node-t8wbf 1/1 Running 0 5d20h
calico-node-xpbf5 1/1 Running 0 5d20h
[root@master01 ~]#

七、验证

1、创建服务及svc

[root@master01 ~]# kubectl apply -f nginx_test.yaml
deployment.apps/test-deployment-nginx created
service/default-svc-nginx created
[root@master01 ~]#
[root@master01 ~]# cat nginx_test.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: test-deployment-nginx
  namespace: default
spec:
  replicas: 10
  selector:
    matchLabels:
      run: test-deployment-nginx
  template:
    metadata:
      labels:
        run: test-deployment-nginx
    spec:
      containers:
      - name: test-deployment-nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: default-svc-nginx
  namespace: default
spec:
  selector:
    run: test-deployment-nginx
  type: ClusterIP
  ports:
    - name: nginx-port
      port: 80
      targetPort: 80
[root@master01 ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
default-busybox-675df76b45-xjtkd 1/1 Running 9 (37h ago) 21d 172.30.3.39 node01  
test-deployment-nginx-5f9c89657d-55cjf 1/1 Running 0 33s 172.30.235.3 master03  
test-deployment-nginx-5f9c89657d-9br8j 1/1 Running 0 33s 172.30.241.68 master01  
test-deployment-nginx-5f9c89657d-cdccb 1/1 Running 0 33s 172.30.196.129 node01  
test-deployment-nginx-5f9c89657d-dx2vh 1/1 Running 0 33s 172.30.140.69 node02  
test-deployment-nginx-5f9c89657d-m796j 1/1 Running 0 33s 172.30.235.4 master03  
test-deployment-nginx-5f9c89657d-nm95d 1/1 Running 0 33s 172.30.241.67 master01  
test-deployment-nginx-5f9c89657d-pp6vb 1/1 Running 0 33s 172.30.196.130 node01  
test-deployment-nginx-5f9c89657d-r5ghr 1/1 Running 0 33s 172.30.59.196 master02  
test-deployment-nginx-5f9c89657d-s5bd8 1/1 Running 0 33s 172.30.59.195 master02  
test-deployment-nginx-5f9c89657d-wwlql 1/1 Running 0 33s 172.30.140.70 node02  
[root@master01 ~]#

2、验证DNS

[root@master01 ~]# kubectl exec -it default-busybox-675df76b45-xjtkd /bin/bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
OCI runtime exec failed: exec failed: container_linux.go:380: starting container process caused: exec: "/bin/bash": stat /bin/bash: no such file or directory: unknown
command terminated with exit code 126
[root@master01 ~]# kubectl exec -it default-busybox-675df76b45-xjtkd /bin/sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
/ # wget -O index.html 10.105.18.45
Connecting to 10.105.18.45 (10.105.18.45:80)
saving to 'index.html'
index.html 100% |*********************************************************************************************************************************************************| 612 0:00:00 ETA
'index.html' saved
/ # curl http://
/bin/sh: curl: not found
/ # rm -rf index.html
/ # wget -O index.html http://default-svc-nginx.default
Connecting to default-svc-nginx.default (10.105.18.45:80)
saving to 'index.html'
index.html 100% |*********************************************************************************************************************************************************| 612 0:00:00 ETA
'index.html' saved
/ # ls
bin dev etc home index.html proc root sys tmp usr var
/ # ping default-svc-nginx
PING default-svc-nginx (10.105.18.45): 56 data bytes
64 bytes from 10.105.18.45: seq=0 ttl=64 time=0.136 ms
^C
--- default-svc-nginx ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.136/0.136/0.136 ms
/ # exit
[root@master01 ~]#

从上可以看出pod不仅可以访问自己的service名称，也可访问其它名称空间的serviceName.NAMESPACE。

3、查看集群状态

[root@master01 ~]# 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","reason":""}
etcd-0 Healthy {"health":"true","reason":""}
etcd-1 Healthy {"health":"true","reason":""}
[root@master01 ~]# kubectl get node -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
master01 Ready control-plane,master 21d v1.23.1 100.109.86.40  CentOS Linux 8 4.18.0-305.3.1.el8.x86_64 docker://20.10.12
master02 Ready control-plane,master 21d v1.23.1 100.109.86.41  CentOS Linux 8 4.18.0-305.3.1.el8.x86_64 docker://20.10.12
master03 Ready control-plane,master 21d v1.23.1 100.109.86.42  CentOS Linux 8 4.18.0-305.3.1.el8.x86_64 docker://20.10.12
node01 Ready  21d v1.23.1 100.109.86.43  CentOS Linux 8 4.18.0-305.3.1.el8.x86_64 docker://20.10.12
node02 Ready  21d v1.23.1 100.109.79.13  CentOS Linux 8 4.18.0-305.3.1.el8.x86_64 docker://20.10.12
[root@master01 ~]#

八、总结

kuberadm安装kubernetes v1.23.1还是非常简单的，有一个关键的点，需要注意一下，如果你弄高可用集群，建议在默认init时，指定的配置文件当中，要指定这个 controlPlaneEndpoint: 192.168.86.40:6443，初始化完成后才会有kubeadm join加入master节点control-plane命令参数和node节点加入集群的命令参数；还有一个地方需要注意，master01初始化完成后，需要把生成的pki下面的证书和私钥copy到其它的master节点，再执行kubeadm join，否则失败。