kubeadm是官方社区推出的一个用于快速部署kubernetes集群的工具。

这个工具能通过两条指令完成一个kubernetes集群的部署：

# 创建一个 Master 节点

$ kubeadm init

# 将一个 Node 节点加入到当前集群中

$ kubeadm join <Master节点的IP和端口 >

1.安装要求

在开始之前，部署Kubernetes集群机器需要满足以下几个条件：

1. 一台或多台机器，操作系统 CentOS7.x-86_x64
2. 硬件配置：2GB或更多RAM，2个CPU或更多CPU，硬盘8GB或更多
3. 可以访问外网，需要拉取镜像，如果服务器不能上网，需要提前下载镜像并导入节点
4. 禁止swap分区

2. 准备环境

角色	IP	主机名<hostname>
master1	10.3.3.41	master1
master2	10.3.3.48	master2
master3	10.3.3.115	master3
node1	10.3.3.181	node1
VIP（虚拟ip）	10.3.3.88

   系统优化

# 关闭防火墙

systemctl disable firewalld --now

# 关闭selinux

sudo sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久

setenforce 0  # 临时

# 关闭swap

 swapoff -a  # 临时

sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久

# 根据规划设置主机名

sudo hostnamectl set-hostname <hostname>

# 在master添加hosts

sudo cat >> /etc/hosts << EOF

10.3.3.88    master.k8s.io   k8s-vip

10.3.3.41    master01.k8s.io master1

1 0.3.3.48    master02.k8s.io master2

10.3.3.115   master03.k8s.io master3

10.3.3.181   node01.k8s.io   node1 

 EOF

或者sudo vim /etc/hosts 编辑

# 所有机器将桥接的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

或者sudo vim /etc/sysctl.d/k8s.conf 编辑

sudo sysctl --system  # 生效 

# 时间同步

sudo yum install ntpdate -y

sudo ntpdate time.windows.com

#时区修改

tzselect  

#4

#9

#1

#1

export TZ='Asia/Shanghai'

source ~/.bashrc

sudo rm -f /etc/localtime

sudo ln -s /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

#K8s内核优化

cat <<EOF >> /etc/security/limits.conf

* soft nofile 655360

* hard nofile 131072

* soft nproc 655350

* hard nproc 655350

* soft memlock unlimited

* hard memlock unlimited

EOF

或者sudo vim /etc/security/limits.conf

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 = 131072

net.ipv4.tcp_max_syn_backlog = 16384

net.ipv4.tcp_timestamps = 0

net.core.somaxconn = 16384

EOF

或者sudo vim /etc/sysctl.d/k8s.conf

sudo sysctl --system  # 生效    

  

3. 所有master节点部署keepalived

3.1 安装相关包和keepalived

sudo yum install -y conntrack-tools libseccomp libtool-ltdl

sudo yum install -y keepalived

3.2配置master节点

查看interface

ip addr

master1节点配置

cat > /etc/keepalived/keepalived.conf <<EOF 

! Configuration File for keepalived

global_defs {

 router_id LVS_DEVEL

}

vrrp_script check_apiserver {

 script "/etc/keepalived/check_apiserver.sh"

 interval 1

 weight -2

 fall 10

 rise 2

}

vrrp_instance VI_1 {

   state MASTER

   unicast_src_ip 10.3.3.41

   unicast_peer {

10.3.3.48

10.3.3.115

   }

   interface eth0

   virtual_router_id 51

   priority 100

   advert_int 1

   authentication {

       auth_type PASS

       auth_pass 4be37dc3b4c90194d1600c483e10ad1d

   }

   virtual_ipaddress {

      10.3.3.88/24

   }

   track_script {

       check_apiserver

   }

   notify_master "/etc/keepalived/assign_private_ip.sh 10.3.3.88 i-094f29f72ebc2d78d"

   notify_backup "/etc/keepalived/unassign_private_ip.sh 10.3.3.88 i-094f29f72ebc2d78d"

}

EOF

或者sudo vim /etc/keepalived/keepalived.conf

master2节点配置

cat > /etc/keepalived/keepalived.conf <<EOF 

! Configuration File for keepalived

global_defs {

 router_id LVS_DEVEL

}

vrrp_script check_apiserver {

 script "/etc/keepalived/check_apiserver.sh"

 interval 1

 weight -2

 fall 10

 rise 2

}

vrrp_instance VI_1 {

   state BACKUP

   unicast_src_ip 10.3.3.48

   unicast_peer {

10.3.3.41

10.3.3.115

   }

   interface eth0

   virtual_router_id 51

   priority 90

   advert_int 1

   authentication {

       auth_type PASS

       auth_pass 4be37dc3b4c90194d1600c483e10ad1d

   }

   virtual_ipaddress {

      10.3.3.88/24

   }

   track_script {

       check_apiserver

   }

   notify_master "/etc/keepalived/assign_private_ip.sh 10.3.3.88 i-0c0ab1b8651b4aa9e"

   notify_backup "/etc/keepalived/unassign_private_ip.sh 10.3.3.88 i-0c0ab1b8651b4aa9e"

}

EOF

或者sudo vim /etc/keepalived/keepalived.conf

Master3节点配置

cat > /etc/keepalived/keepalived.conf <<EOF 

 ! Configuration File for keepalived

global_defs {

 router_id LVS_DEVEL

}

vrrp_script check_apiserver {

 script "/etc/keepalived/check_apiserver.sh"

 interval 1

 weight -2

 fall 10

 rise 2

}

vrrp_instance VI_1 {

   state BACKUP

   unicast_src_ip 10.3.3.115

   unicast_peer {

10.3.3.41

10.3.3.48

   }

   interface eth0

   virtual_router_id 51

   priority 80

   advert_int 1

   authentication {

       auth_type PASS

       auth_pass 4be37dc3b4c90194d1600c483e10ad1d

   }

   virtual_ipaddress {

      10.3.3.88/24

   }

   track_script {

       check_apiserver

   }

   notify_master "/etc/keepalived/assign_private_ip.sh 10.3.3.88 i-0c0ab1b8651b4aa9e"

   notify_backup "/etc/keepalived/unassign_private_ip.sh 10.3.3.88 i-0c0ab1b8651b4aa9e"

} 

EOF

或者sudo vim /etc/keepalived/keepalived.conf

3.3 健康监测脚本，每台master都必须有

cat > /etc/keepalived/check_apiserver.sh <<"EOF"

#!/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"

  systemctl stop keepalived

  exit 1

else

  exit 0

fi

EOF

chmod +x /etc/keepalived/check_apiserver.sh

3.4 master机器上面配置shell 脚本切换IP

前提:三台master集群配置ak,sk

• sudo vim /etc/keepalived/assign_private_ip.sh

#!/bin/bash

LOG=/etc/keepalived/keepalived.log

IP=$1

INSTANCE_ID=$2

VIP=10.3.3.88

ENI=$(aws ec2 describe-instances --instance-ids $INSTANCE_ID | jq -r '.Reservations[0].Instances[0].NetworkInterfaces[0].NetworkInterfaceId')

echo $(date) >> ${LOG}

echo "Adding IP $IP to ENI $ENI success" >> ${LOG}

aws ec2 assign-private-ip-addresses --network-interface-id $ENI --private-ip-addresses $IP --allow-reassignment

echo "Adding IP $IP success1" >> ${LOG}

sudo ip address add $VIP/24 dev eth0 >> ${LOG}

echo "Adding IP $IP success2" >> ${LOG}

• sudo vim /etc/keepalived/unassign_private_ip.sh

#!/bin/bash

IP=$1

INSTANCE_ID=$2

VIP=10.3.3.88

LOG=/etc/keepalived/keepalived.log

ENI=$(aws ec2 describe-instances --instance-ids $INSTANCE_ID | jq -r '.Reservations[0].Instances[0].NetworkInterfaces[0].NetworkInterfaceId')

echo $(date) >> ${LOG}

echo "Removing IP $IP from ENI $ENI" >> ${LOG}

sudo aws ec2 unassign-private-ip-addresses --network-interface-id $ENI --private-ip-addresses $IP

sudo p address del $VIP/24 dev eth0 >> ${LOG}

echo "remove ip success" >> ${LOG}

3.5 启动和检查

在三台master节点都执行

  # 启动keepalived

$sudo systemctl start keepalived.service

设置开机启动

$sudo  systemctl enable keepalived.service

# 查看启动状态

 $sudo  systemctl status keepalived.service 

启动后查看master1的网卡信息

ip a s eth0  

4. 部署haproxy

4.1 安装

sudo yum install -y haproxy

4.2 配置

三台master节点的配置均相同，配置中声明了后端代理的两个master节点服务器，指定了haproxy运行的端口为16443等，因此16443端口为集群的入口

 cat > /etc/haproxy/haproxy.cfg << EOF

#---------------------------------------------------------------------

# Global settings

#---------------------------------------------------------------------

global

    # to have these messages end up in /var/log/haproxy.log you will

    # need to:

     # 1) configure syslog to accept network log events.  This is done

     #    by adding the '-r' option to the SYSLOGD_OPTIONS in

    #    /etc/sysconfig/syslog

    # 2) configure local2 events to go to the /var/log/haproxy.log

    #   file. A line like the following can be added to

    #   /etc/sysconfig/syslog

    #

    #    local2.*                       /var/log/haproxy.log

    #

    log /dev/log local0

    log /dev/log local1 notice

    daemon

       

    # turn on stats unix socket

    stats socket /var/lib/haproxy/stats

#---------------------------------------------------------------------

# common defaults that all the 'listen' and 'backend' sections will

# use if not designated in their block

#---------------------------------------------------------------------  

defaults

log global

mode http

option httplog

    retries                 3

    timeout http-request    10s

      timeout queue           1m

    timeout connect         10s

     timeout client          1m

    timeout server          1m

    timeout http-keep-alive 10s

     timeout check           10s

maxconn                 3000    

frontend monitor-in

  bind *:33305 

  mode http

  option httplog

  monitor-uri /monitor 

listen stats

  bind    *:8006

  mode    http

  stats   enable

  stats   hide-version

  stats   uri       /stats

  stats   refresh   30s 

  stats   realm     Haproxy\ Sta tistics

  stats   auth      admin:admin

#---------------------------------------------------------------------

# apiserver frontend which proxys to the masters

#---------------------------------------------------------------------

frontend apiserver

    bind *:16443

    mode tcp

    option tcplog

    default_backend apiserver

#---------------------------------------------------------------------

# round robin balancing for apiserver

#---------------------------------------------------------------------

 backend apiserver

    option httpchk GET /healthz

option ssl-hello-chk

    http-check expect status 200

    mode tcp

    balance     roundrobin

   server master1 10.3.3.41:6443 check

     server master2 10.3.3.48:6443 check

    server master3 10.3.3.115:6443 check   

EOF

或者sudo vim /etc/haproxy/haproxy.cfg

http://69.230.210.85:8006/stats 

4.3 启动和检查

两台master都启动

 # 设置开机启动

 $ sudo systemctl enable haproxy

# 开启haproxy

$ sudo  systemctl start haproxy 

 # 查看启动状态

$ sudo  systemctl status haproxy

检查端口

sudo netstat -lntup|grep haproxy  

5. 所有节点安装Docker/kubeadm/kubelet

Kubernetes默认CRI（容器运行时）为Docker，因此先安装Docker。

5.1 安装Docker（aws参考docker安装）

 $ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo

$ yum -y install docker-ce-18.06.1.ce-3.el7

 $ systemctl enable docker && systemctl start docker

$ docker --version

Docker version 18.06.1-ce, build e68fc7a

$ cat > /etc/docker/daemon.json << EOF

{

"exec-opts": ["native.cgroupdriver=systemd"],

 "registry-mirrors": ["https://docker.mirrors.ustc.edu.cn"],

"log-driver": "json-file",
"log-opts": {

"max-size":"500m",

"max-file":"3"
},

"storage-driver": "overlay2",

"storage-opts": [ "overlay2.override_kernel_check=true" ]

} 

EOF 

或者sudo vim /etc/docker/daemon.json

sudo systemctl daemon-reload

sudo systemctl restart docker

sudo systemctl enable docker.service

5.2 添加阿里云YUM软件源

 $ 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

或者sudo vim /etc/yum.repos.d/kubernetes.repo  

5.3 安装kubeadm，kubelet和kubectl

由于版本更新频繁，这里指定版本号部署：

 #分别查询1.22.5包是否在yum源里

sudo yum list kubelet --showduplicates | sort -r

sudo yum list kubectl --showduplicates | sort -r

sudo yum list kubeadm --showduplicates | sort -r

$ sudo yum install -y kubelet-1.22.5 kubeadm-1.22.5 kubectl-1.22.5

$ sudo systemctl enable kubelet 

6. 部署Kubernetes Master

6.1 创建kubeadm配置文件

部署完高可用软件完再部署k8s容器

kubeadm config print init-defaults > kubeadm-init.yaml

在具有vip的master上操作，这里为master1

$ sudo vim 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: 10.3.3.41  <<---当前主机IP

  bindPort: 6443

nodeRegistration:

  criSocket: /var/run/dockershim.sock

  imagePullPolicy: IfNotPresent

  name: master1              <<--当前主机名还有下面三行

  taints:

  - effect: NoSchedule

    key: node-role.kubernetes.io/master

---

 apiServer:

  certSANs:

   - 10.3.3.88        <<----VIP

  timeoutForControlPlane: 4m0s

apiVersion: kubeadm.k8s.io/v1beta3

certificatesDir: /etc/kubernetes/pki

clusterName: kubernetes

controlPlaneEndpoint: 10.3.3.88:16443   <<<---VIP 

controllerManager: {}

dns: 

  type: CoreDNS   <<----手动添加

etcd:

  local:

    dataDir: /var/lib/etcd

imageRepository: registry.aliyuncs.com/google_containers

kind: ClusterConfiguration

kubernetesVersion: 1.22.5

networking:

  dnsDomain: cluster.local

  podSubnet: 10.244.0.0/16 <<----可以默认 注意与之后部署容器网络(CNI)里面定义Pod网络一致

  serviceSubnet: 10.96.0.0/16  <<----可以默认

scheduler: {} 

6.2 在master1节点执行

手动拉取镜像【加速】

sudo kubeadm config images pull --image-repository=registry.aliyuncs.com/google_containers

$ sudo kubeadm init --config kubeadm-init.yaml --upload-certs --ignore-preflight-errors=all --v=5

或者sudo kubeadm init --apiserver-advertise-address=10.3.3.4 --image-repository registry.aliyuncs.com/google_containers --kubernetes-version v1.22.5 --service-cidr=10.96.0.0/12 --pod-network-cidr=10.244.0.0/16 --control-plane-endpoint 10.3.3.4:6443 --ignore-preflight-errors=all(需要copy 证书到其他的master)

注意 ：如果出现 Error writing Crisocket information for the control-plane node: timed out waiting for the condition

重启 kubeadm 然后再执行init

sudo kubeadm reset

按照提示配置环境变量，使用kubectl工具：

 $ mkdir -p $HOME/.kube

$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

 

$ sudo chown $(id -u):$(id -g) $HOME/.kube/config

$ kubectl get nodes

$ kubectl get pods -n kube-system 

6.3、添加kubectl补全功能

sudo yum -y install bash-completion && cd ~;echo "source <(kubectl completion bash)" >> .bashrc

按照提示保存以下内容，一会要使用：

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

kubeadm join 10.3.3.54:6443 --token abcdef.0123456789abcdef \

--discovery-token-ca-cert-hash sha256:30cd7726c990de6288d144178095122c1149ef237c3ab85f6e68ce46d96578e8 \

--control-plane --certificate-key 77dfd4ee1a71f1a531d1ee2128469a728466a9add052acd14f2a9fda04c595e8

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

kubeadm join 10.3.3.54:6443 --token abcdef.0123456789abcdef --discovery-token-ca-cert-hash sha256:30cd7726c990de6288d144178095122c1149ef237c3ab85f6e68ce46d96578e8

查看集群状态

 kubectl get cs

kubectl get pods -n kube-system 

7.安装集群网络

从官方地址获取到calico的yaml，在master1上执行

wget https://docs.projectcalico.org/manifests/calico.yaml

修改CALICO_IPV4POOL_CIDR为自定义地址

该地址与kubeadm init指定pod-network-cidr一致

 

安装calico网络

kubectl apply -f calico.yaml

检查

kubectl get pods -n kube-system

安装flannel

 

跟pod一样

 kubectl apply -f flannel.yaml 

集群部署后scheduler状态为Unhealthy

在安装网络插件之后再修改此处，所有的master都修改

sudo vim /etc/kubernetes/manifests/kube-scheduler.yaml

sudo vim /etc/kubernetes/manifests/kube-controller-manager.yaml

- --port=0 注释

重启

sudo systemctl restart kubelet.service

8、master2节点加入集群

8.1 master2,master3加入集群

执行在master1上init后输出的join命令,需要带上参数--control-plane表示把master控制节点加入集群

sudo kubeadm join 10.3.3.88:16443 --token abcdef.0123456789abcdef \

--discovery-token-ca-cert-hash sha256:30cd7726c990de6288d144178095122c1149ef237c3ab85f6e68ce46d96578e8 \

--control-plane --certificate-key  --ignore-preflight-errors=all --v=5

检查状态

 kubectl get node

kubectl get pods --all-namespaces 

9. 加入Kubernetes Node

在node1上执行

向集群添加新节点，执行在kubeadm init输出的kubeadm join命令：

sudo kubeadm join 10.3.3.88:16443 --token abcdef.0123456789abcdef --discovery-token-ca-cert-hash sha256:30cd7726c990de6288d144178095122c1149ef237c3ab85f6e68ce46d96578e8  --ignore-preflight-errors=all --v=5

检查状态

kubectl get node

kubectl get pods --all-namespaces

 

10. 测试kubernetes集群

在Kubernetes集群中创建一个pod，验证是否正常运行：

$ kubectl create deployment nginx --image=nginx

$ kubectl expose deployment nginx --port=80 --type=NodePort

$ kubectl get pod,svc

访问：curl http://10.3.3.41:31552