kubernetes企业级高可用部署

目录

1、Kubernetes高可用项目介绍

2、项目架构设计

2.1、项目主机信息

2.2、项目架构图

1、Kubernetes高可用项目介绍

2、项目架构设计

2.1、项目主机信息

2.2、项目架构图

2.3、项目实施思路

3、项目实施过程

3.1、系统初始化

3.2、配置部署keepalived服务

3.3、配置部署haproxy服务

3.4、配置部署Docker服务

3.5、部署kubelet kubeadm kubectl工具

3.6、部署Kubernetes Master

3.6、部署Kubernetes Master

3.7、安装集群网络

3.8、添加master节点

3.9、加入Kubernetes Node

3.10、测试Kubernetes集群

4、项目总结

---

1、Kubernetes高可用项目介绍

单master节点的可靠性不高，并不适合实际的生产环境。Kubernetes 高可用集群是保证 Master 节点中 API Server 服务的高可用。API Server 提供了 Kubernetes 各类资源对象增删改查的唯一访问入口，是整个 Kubernetes 系统的数据总线和数据中心。采用负载均衡（Load Balance）连接多个 Master 节点可以提供稳定容器云业务。

2、项目架构设计

2.1、项目主机信息

准备6台虚拟机，3台master节点，3台node节点，保证master节点数为>=3的奇数。

硬件：2核CPU+、2G内存+、硬盘20G+

网络：所有机器网络互通、可以访问外网

操作系统	IP地址	角色	主机名
CentOS7-x86-64	192.168.200.111	master	k8s-master1
CentOS7-x86-64	192.168.200.112	master	k8s-master2
CentOS7-x86-64	192.168.200.113	master	k8s-master3
CentOS7-x86-64	192.168.200.114	node	k8s-node1
CentOS7-x86-64	192.168.200.115	node	k8s-node2
CentOS7-x86-64	192.168.200.116	node	k8s-node3
	192.168.200.154	VIP	master.k8s.io

2.2、项目架构图

多master节点负载均衡的kubernetes集群。官网给出了两种拓扑结构：堆叠control plane node和external etcd node，本文基于第一种拓扑结构进行搭建。

1、Kubernetes高可用项目介绍

单master节点的可靠性不高，并不适合实际的生产环境。Kubernetes 高可用集群是保证 Master 节点中 API Server 服务的高可用。API Server 提供了 Kubernetes 各类资源对象增删改查的唯一访问入口，是整个 Kubernetes 系统的数据总线和数据中心。采用负载均衡（Load Balance）连接多个 Master 节点可以提供稳定容器云业务。

2、项目架构设计

2.1、项目主机信息

准备6台虚拟机，3台master节点，3台node节点，保证master节点数为>=3的奇数。

硬件：2核CPU+、2G内存+、硬盘20G+、开启虚拟化

网络：所有机器网络互通、可以访问外网

操作系统	IP地址	角色	主机名
CentOS7-x86-64	192.168.147.137	master	k8s-master1
CentOS7-x86-64	192.168.147.139	master	k8s-master2
CentOS7-x86-64	192.168.147.140	master	k8s-master3
CentOS7-x86-64	192.168.147.141	node	k8s-node1
CentOS7-x86-64	192.168.147.142	node	k8s-node2
CentOS7-x86-64	192.168.147.143	node	k8s-node3
	192.168.147.154	VIP	master.k8s.io

2.2、项目架构图

多master节点负载均衡的kubernetes集群。官网给出了两种拓扑结构：堆叠control plane node和external etcd node，本文基于第一种拓扑结构进行搭建。

 

 （堆叠control plane node）

 （external etcd node）

2.3、项目实施思路

master节点需要部署etcd、apiserver、controller-manager、scheduler这4种服务，其中etcd、controller-manager、scheduler这三种服务kubernetes自身已经实现了高可用，在多master节点的情况下，每个master节点都会启动这三种服务，同一时间只有一个生效。因此要实现kubernetes的高可用，只需要apiserver服务高可用。

keepalived是一种高性能的服务器高可用或热备解决方案，可以用来防止服务器单点故障导致服务中断的问题。keepalived使用主备模式，至少需要两台服务器才能正常工作。比如keepalived将三台服务器搭建成一个集群，对外提供一个唯一IP，正常情况下只有一台服务器上可以看到这个IP的虚拟网卡。如果这台服务异常，那么keepalived会立即将IP移动到剩下的两台服务器中的一台上，使得IP可以正常使用。

haproxy是一款提供高可用性、负载均衡以及基于TCP（第四层）和HTTP（第七层）应用的代理软件，支持虚拟主机，它是免费、快速并且可靠的一种解决方案。使用haproxy负载均衡后端的apiserver服务，达到apiserver服务高可用的目的。

本文使用的keepalived+haproxy方案，使用keepalived对外提供稳定的入口，使用haproxy对内均衡负载。因为haproxy运行在master节点上，当master节点异常后，haproxy服务也会停止，为了避免这种情况，我们在每一台master节点都部署haproxy服务，达到haproxy服务高可用的目的。由于多master节点会出现投票竞选的问题，因此master节点的数据最好是单数，避免票数相同的情况。

3、项目实施过程

3.1、系统初始化

所有主机：

关闭防火墙、selinux、swap

[root@client2 ~]#  systemctl stop firewalld
[root@client2 ~]# systemctl disable firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[root@client2 ~]#  sed -i 's/enforcing/disabled/' /etc/selinux/config
[root@client2 ~]#  setenforce 0
[root@client2 ~]#  swapoff -a
[root@client2 ~]# sed -ri 's/.*swap.*/#&/' /etc/fstab

修改主机名（根据主机角色不同，做相应修改）

[root@client2 ~]# hostnamectl set-hostname k8s-master1
[root@client2 ~]# hostnamectl set-hostname k8s-master2
[root@client2 ~]# hostnamectl set-hostname k8s-master3
[root@k8s-node1 ~]# hostnamectl set-hostname k8s-node1
[root@k8s-node1 ~]# hostnamectl set-hostname k8s-node2
[root@k8s-node1 ~]# hostnamectl set-hostname k8s-node3

[root@k8s-node1 ~]# vim /etc/hosts
192.168.147.137 master 1.k8s.io k8s-master1
192.168.147.139 master 2.k8s.io k8s-master2
192.168.147.140 master 3.k8s.io k8s-master3
192.168.147.141 node1.k8s.io k8s-node1
192.168.147.142 node2.k8s.io k8s-node2
192.168.147.143 node3.k8s.io k8s-node3
192.168.147.154 master.k8s.io k8s-vip
[root@k8s-node1 ~]# scp /etc/hosts 192.168.147.137:/etc/hosts
[root@k8s-node1 ~]# scp /etc/hosts 192.168.147.139:/etc/hosts
[root@k8s-node1 ~]# scp /etc/hosts 192.168.147.140:/etc/hosts
[root@k8s-node1 ~]# scp /etc/hosts 192.168.147.142:/etc/hosts
[root@k8s-node1 ~]# scp /etc/hosts 192.168.147.143:/etc/hosts

将桥接的IPv4流量传递到iptables的链

[root@k8s-master1 ~]# cat << EOF >> /etc/sysctl.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
[root@k8s-master1 ~]# modprobe br_netfilter
[root@k8s-master1 ~]# sysctl -p

时间同步

[root@k8s-master1 ~]# yum install ntpdate -y
[root@k8s-master1 ~]# ntpdate time.windows.com

3.2、配置部署keepalived服务

安装Keepalived（所有master主机）

[root@k8s-master1 ~]# yum install -y keepalived

k8s-master1节点配置 

[root@k8s-master1 ~]# cat > /etc/keepalived/keepalived.conf <

k8s-master2节点配置

[root@k8s-master2 ~]# cat > /etc/keepalived/keepalived.conf <

 k8s-master3节点配置

[root@k8s-master3 ~]# cat > /etc/keepalived/keepalived.conf <

启动和检查

所有master节点都要执行

[root@k8s-master1 ~]#  systemctl start keepalived
[root@k8s-master1 ~]#  systemctl enable keepalived
Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service.

 查看启动状态

[root@k8s-master1 ~]# systemctl status keepalived
● keepalived.service - LVS and VRRP High Availability Monitor
   Loaded: loaded (/usr/lib/systemd/system/keepalived.service; enabled; vendor preset: disabled)
   Active: active (running) since 二 2023-08-15 13:38:02 CST; 10s ago
 Main PID: 18740 (keepalived)
   CGroup: /system.slice/keepalived.service
           ├─18740 /usr/sbin/keepalived -D
           ├─18741 /usr/sbin/keepalived -D
           └─18742 /usr/sbin/keepalived -D

8月 15 13:38:04 k8s-master1 Keepalived_vrrp[18742]: Sending gratuitous ARP on ens33 for 192.168.147.154
8月 15 13:38:04 k8s-master1 Keepalived_vrrp[18742]: Sending gratuitous ARP on ens33 for 192.168.147.154
8月 15 13:38:04 k8s-master1 Keepalived_vrrp[18742]: Sending gratuitous ARP on ens33 for 192.168.147.154
8月 15 13:38:04 k8s-master1 Keepalived_vrrp[18742]: Sending gratuitous ARP on ens33 for 192.168.147.154
8月 15 13:38:09 k8s-master1 Keepalived_vrrp[18742]: Sending gratuitous ARP on ens33 for 192.168.147.154
8月 15 13:38:09 k8s-master1 Keepalived_vrrp[18742]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on ens33 f....154
8月 15 13:38:09 k8s-master1 Keepalived_vrrp[18742]: Sending gratuitous ARP on ens33 for 192.168.147.154
8月 15 13:38:09 k8s-master1 Keepalived_vrrp[18742]: Sending gratuitous ARP on ens33 for 192.168.147.154
8月 15 13:38:09 k8s-master1 Keepalived_vrrp[18742]: Sending gratuitous ARP on ens33 for 192.168.147.154
8月 15 13:38:09 k8s-master1 Keepalived_vrrp[18742]: Sending gratuitous ARP on ens33 for 192.168.147.154
Hint: Some lines were ellipsized, use -l to show in full.

启动完成后在master1查看网络信息

[root@k8s-master1 ~]# ip a s ens33
2: ens33:  mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:c7:3f:d6 brd ff:ff:ff:ff:ff:ff
    inet 192.168.147.137/24 brd 192.168.147.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.147.154/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::bd67:1ba:506d:b021/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::146a:2496:1fdc:4014/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::5d98:c5e3:98f8:181/64 scope link tentative noprefixroute dadfailed 

3.3、配置部署haproxy服务

所有master主机安装haproxy

[root@k8s-master1 ~]# yum install -y haproxy

每台master节点中的配置均相同，配置中声明了后端代理的每个master节点服务器，指定了haproxy的端口为16443，因此16443端口为集群的入口。

[root@k8s-master1 ~]# cat > /etc/haproxy/haproxy.cfg << EOF
> #-------------------------------
> # Global settings
> #-------------------------------
> global
>   log       127.0.0.1 local2
>   chroot    /var/lib/haproxy
>   pidfile   /var/run/haproxy.pid
>   maxconn   4000
>   user      haproxy
>   group     haproxy
>   daemon
>   stats socket /var/lib/haproxy/stats
> #--------------------------------
> # common defaults that all the 'listen' and 'backend' sections will
> # usr if not designated in their block
> #--------------------------------
> defaults
>   mode                http
>   log                 global
>   option              httplog
>   option              dontlognull
>   option http-server-close
>   option forwardfor   except 127.0.0.0/8
>   option              redispatch
>   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
> #--------------------------------
> # kubernetes apiserver frontend which proxys to the backends
> #--------------------------------
> frontend kubernetes-apiserver
>   mode              tcp
>   bind              *:16443
>   option            tcplog
>   default_backend   kubernetes-apiserver
> #---------------------------------
> #round robin balancing between the various backends
> #---------------------------------
> backend kubernetes-apiserver
>   mode              tcp
>   balance           roundrobin
>   server            master1.k8s.io    192.168.147.137:6443 check
>   server            master2.k8s.io    192.168.147.139:6443 check
>   server            master3.k8s.io    192.168.147.140:6443 check
> #---------------------------------
> # collection haproxy statistics message
> #---------------------------------
> listen stats
>   bind              *:1080
>   stats auth        admin:awesomePassword
>   stats refresh     5s
>   stats realm       HAProxy\ Statistics
>   stats uri         /admin?stats
> EOF

启动和检查

所有master节点都要执行

[root@k8s-master1 ~]# systemctl start haproxy
[root@k8s-master1 ~]# systemctl enable haproxy

查看启动状态

[root@k8s-master1 ~]#  systemctl status haproxy
● haproxy.service - HAProxy Load Balancer
   Loaded: loaded (/usr/lib/systemd/system/haproxy.service; enabled; vendor preset: disabled)
   Active: active (running) since 二 2023-08-15 13:43:11 CST; 15s ago
 Main PID: 18812 (haproxy-systemd)
   CGroup: /system.slice/haproxy.service
           ├─18812 /usr/sbin/haproxy-systemd-wrapper -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid
           ├─18814 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid -Ds
           └─18818 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid -Ds

8月 15 13:43:11 k8s-master1 systemd[1]: Started HAProxy Load Balancer.
8月 15 13:43:11 k8s-master1 haproxy-systemd-wrapper[18812]: haproxy-systemd-wrapper: executing /usr/sbin/haproxy -f... -Ds
8月 15 13:43:11 k8s-master1 haproxy-systemd-wrapper[18812]: [WARNING] 226/134311 (18814) : config : 'option forward...ode.
8月 15 13:43:11 k8s-master1 haproxy-systemd-wrapper[18812]: [WARNING] 226/134311 (18814) : config : 'option forward...ode.
Hint: Some lines were ellipsized, use -l to show in full.

检查端口

[root@k8s-master1 ~]#  netstat -lntup|grep haproxy
tcp        0      0 0.0.0.0:1080            0.0.0.0:*               LISTEN      18818/haproxy       
tcp        0      0 0.0.0.0:16443           0.0.0.0:*               LISTEN      18818/haproxy       
udp        0      0 0.0.0.0:40763           0.0.0.0:*                           18814/haproxy 

3.4、配置部署Docker服务

所有主机上分别部署 Docker 环境，因为 Kubernetes 对容器的编排需要 Docker 的支持。

[root@k8s-master ~]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
[root@k8s-master ~]# yum install -y yum-utils device-mapper-persistent-data lvm2

使用 YUM 方式安装 Docker 时，推荐使用阿里的 YUM 源

[root@k8s-master ~]# yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
[root@k8s-master ~]# yum clean all && yum makecache fast 

[root@k8s-master ~]# yum -y install docker-ce
[root@k8s-master ~]# systemctl start docker
[root@k8s-master ~]# systemctl enable docker

镜像加速器（所有主机配置）

[root@k8s-master ~]# cat << END > /etc/docker/daemon.json
{
        "registry-mirrors":[ "https://nyakyfun.mirror.aliyuncs.com" ]
}
END
[root@k8s-master ~]# systemctl daemon-reload
[root@k8s-master ~]# systemctl restart docker

3.5、部署kubelet kubeadm kubectl工具

使用 YUM 方式安装Kubernetes时，推荐使用阿里的yum。

所有主机配置

[root@k8s-master ~]# cat < /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

[root@k8s-master ~]# ls /etc/yum.repos.d/
[root@k8s-node3 ~]# ls /etc/yum.repos.d
backup  CentOS-Base.repo  CentOS-Media.repo  docker-ce.repo  kubernetes.repo

安装kubelet kubeadm kubectl

所有主机配置

[root@k8s-master ~]# yum install -y kubelet-1.20.0 kubeadm-1.20.0 kubectl-1.20.0
[root@k8s-master ~]# systemctl enable kubelet

3.6、部署Kubernetes Master

在具有vip的master上操作。此处的vip节点为k8s-master1。

创建kubeadm-config.yaml文件

[root@k8s-master1 ~]# cat > kubeadm-config.yaml << EOF
apiServer:
  certSANs:
    - k8s-master1
    - k8s-master2
    - k8s-master3
    - master.k8s.io
    - 192.168.147.137
    - 192.168.147.139
    - 192.168.147.140
    - 192.168.147.154
    - 127.0.0.1
  extraArgs:
    authorization-mode: Node,RBAC
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta1
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: "master.k8s.io:6443"
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.20.0
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16
  serviceSubnet: 10.1.0.0/16
scheduler: {}
EOF

3.6、部署Kubernetes Master

在具有vip的master上操作。此处的vip节点为k8s-master1。

创建kubeadm-config.yaml文件

[root@k8s-master1 ~]# cat > kubeadm-config.yaml << EOF
apiServer:
  certSANs:
    - k8s-master1
    - k8s-master2
    - k8s-master3
    - master.k8s.io
    - 192.168.147.137
    - 192.168.147.139
    - 192.168.147.140
    - 192.168.147.154
    - 127.0.0.1
  extraArgs:
    authorization-mode: Node,RBAC
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta1
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: "master.k8s.io:6443"
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.20.0
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16
  serviceSubnet: 10.1.0.0/16
scheduler: {}
EOF

查看所需镜像信息

[root@k8s-master1 ~]# kubeadm config images list --config kubeadm-config.yaml
W0815 13:55:35.933304   19444 common.go:77] your configuration file uses a deprecated API spec: "kubeadm.k8s.io/v1beta1". Please use 'kubeadm config migrate --old-config old.yaml --new-config new.yaml', which will write the new, similar spec using a newer API version.
registry.aliyuncs.com/google_containers/kube-apiserver:v1.20.0
registry.aliyuncs.com/google_containers/kube-controller-manager:v1.20.0
registry.aliyuncs.com/google_containers/kube-scheduler:v1.20.0
registry.aliyuncs.com/google_containers/kube-proxy:v1.20.0
registry.aliyuncs.com/google_containers/pause:3.2
registry.aliyuncs.com/google_containers/etcd:3.4.13-0
registry.aliyuncs.com/google_containers/coredns:1.7.0

上传k8s所需的镜像并导入（所有master主机）

[root@k8s-master1 ~]# mkdir master
[root@k8s-master1 ~]# cd master/
[root@k8s-master1 master]# rz -E
rz waiting to receive.
[root@k8s-master1 master]# ls
coredns_1.7.0.tar  kube-apiserver_v1.20.0.tar           kube-proxy_v1.20.0.tar      pause_3.2.tar
etcd_3.4.13-0.tar  kube-controller-manager_v1.20.0.tar  kube-scheduler_v1.20.0.tar
[root@k8s-master1 master]# ls | while read line
> do
> docker load < $line
> done
225df95e717c: Loading layer  336.4kB/336.4kB
96d17b0b58a7: Loading layer  45.02MB/45.02MB

[root@k8s-master1 ~]# scp master/* 192.168.147.139:/root/master
[root@k8s-master1 ~]# scp master/* 192.168.147.140:/root/master
[root@k8s-master2/3 master]# ls | while read line
> do
> docker load < $line
> done

使用kubeadm命令初始化k8s

[root@k8s-master1 ~]# kubeadm init --config kubeadm-config.yaml

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 control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:

  kubeadm join master.k8s.io:6443 --token zus2jc.brtsxszpyv03a57j \
    --discovery-token-ca-cert-hash sha256:20a551796d33309f20ad7579c710ea766ef39b64b98c37a4a4029a903f23300a \
    --control-plane 

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

kubeadm join master.k8s.io:6443 --token zus2jc.brtsxszpyv03a57j \
    --discovery-token-ca-cert-hash sha256:20a551796d33309f20ad7579c710ea766ef39b64b98c37a4a4029a903f23300

如果——初始化中的错误：

[ERROR FileContent--proc-sys-net-bridge-bridge-nf-call-iptables]: /proc/sys/net/bridge/bridge-nf-call-iptables contents are not set to 1

执行以下命令后重新执行初始化命令

echo "1" >/proc/sys/net/bridge/bridge-nf-call-iptables

根据初始化的结果操作

[root@k8s-master1 ~]#   mkdir -p $HOME/.kube
[root@k8s-master1 ~]#   sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-master1 ~]#   sudo chown $(id -u):$(id -g) $HOME/.kube/config

查看集群状态

[root@k8s-master1 ~]# kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS      MESSAGE                                                                                       ERROR
scheduler            Unhealthy   Get "http://127.0.0.1:10251/healthz": dial tcp 127.0.0.1:10251: connect: connection refused   
controller-manager   Unhealthy   Get "http://127.0.0.1:10252/healthz": dial tcp 127.0.0.1:10252: connect: connection refused   
etcd-0               Healthy     {"health":"true"}  

注意：出现以上错误情况，是因为/etc/kubernetes/manifests/下的kube-controller-manager.yaml和kube-scheduler.yaml设置的默认端口为0导致的，解决方式是注释掉对应的port即可

修改kube-controller-manager.yaml文件、kube-scheduler.yaml文件

[root@k8s-master1 ~]# vim /etc/kubernetes/manifests/kube-controller-manager.yaml 

    - --leader-elect=true
#    - --port=0
    - --requestheader-client-ca-file=/etc/kubernetes/pki/front-proxy-ca.crt

[root@k8s-master1 ~]# vim /etc/kubernetes/manifests/kube-scheduler.yaml 
    - --leader-elect=true
#    - --port=0
    image: registry.aliyuncs.com/google_containers/kube-scheduler:v1.20.0

查看集群状态

[root@k8s-master1 ~]# kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS    MESSAGE             ERROR
controller-manager   Healthy   ok                  
scheduler            Healthy   ok                  
etcd-0               Healthy   {"health":"true"}

查看pod信息

[root@k8s-master1 ~]# kubectl get pods -n kube-system
NAME                                  READY   STATUS    RESTARTS   AGE
coredns-7f89b7bc75-hdvw8              0/1     Pending   0          5m51s
coredns-7f89b7bc75-jbn4h              0/1     Pending   0          5m51s
etcd-k8s-master1                      1/1     Running   0          6m
kube-apiserver-k8s-master1            1/1     Running   0          6m
kube-controller-manager-k8s-master1   1/1     Running   0          2m56s
kube-proxy-x25rz                      1/1     Running   0          5m51s
kube-scheduler-k8s-master1            1/1     Running   0          2m17s

查看节点信息

[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS     ROLES                  AGE     VERSION
k8s-master1   NotReady   control-plane,master   6m34s   v1.20.0

3.7、安装集群网络

在k8s-master1节点执行

[root@k8s-master1 ~]# rz -E
rz waiting to receive.
[root@k8s-master1 ~]# ll
总用量 52512
-rw-r--r--. 1 root root 53746688 12月 16 2020 flannel_v0.12.0-amd64.tar
-rw-r--r--. 1 root root    14366 11月 13 2020 kube-flannel.yml
[root@k8s-master1 ~]# docker load < flannel_v0.12.0-amd64.tar
256a7af3acb1: Loading layer  5.844MB/5.844MB
d572e5d9d39b: Loading layer  10.37MB/10.37MB
57c10be5852f: Loading layer  2.249MB/2.249MB
7412f8eefb77: Loading layer  35.26MB/35.26MB
05116c9ff7bf: Loading layer   5.12kB/5.12kB
Loaded image: quay.io/coreos/flannel:v0.12.0-amd64
[root@k8s-master1 ~]# kubectl apply -f kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged created
Warning: rbac.authorization.k8s.io/v1beta1 ClusterRole is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io/v1 ClusterRole
clusterrole.rbac.authorization.k8s.io/flannel created
Warning: rbac.authorization.k8s.io/v1beta1 ClusterRoleBinding is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io/v1 ClusterRoleBinding
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds-amd64 created
daemonset.apps/kube-flannel-ds-arm64 created
daemonset.apps/kube-flannel-ds-arm created
daemonset.apps/kube-flannel-ds-ppc64le created
daemonset.apps/kube-flannel-ds-s390x created

再次查看节点信息：

[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS     ROLES                  AGE     VERSION
k8s-master1   NotReady   control-plane,master   8m27s   v1.20.0

还是没有变成Ready：下载cni网络插件

[root@k8s-master1 ~]# tar xf cni-plugins-linux-amd64-v0.8.6.tgz 
[root@k8s-master1 ~]# cp flannel /opt/cni/bin/
[root@k8s-master1 ~]# kubectl apply -f kube-flannel.yml
configmap/kube-flannel-cfg unchanged
daemonset.apps/kube-flannel-ds-amd64 unchanged
daemonset.apps/kube-flannel-ds-arm64 unchanged
daemonset.apps/kube-flannel-ds-arm unchanged
daemonset.apps/kube-flannel-ds-ppc64le unchanged
daemonset.apps/kube-flannel-ds-s390x unchanged
[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS   ROLES                  AGE   VERSION
k8s-master1   Ready    control-plane,master   11m   v1.20.0

3.8、添加master节点

在k8s-master2和k8s-master3节点创建文件夹

[root@k8s-master2 ~]# mkdir -p /etc/kubernetes/pki/etcd

[root@k8s-master3 ~]# mkdir -p /etc/kubernetes/pki/etcd

在k8s-master1节点执行

从k8s-master1复制秘钥和相关文件到k8s-master2和k8s-master3

[root@k8s-master1 ~]# scp /etc/kubernetes/admin.conf [email protected]:/etc/kubernetes 
[root@k8s-master1 ~]# scp /etc/kubernetes/admin.conf [email protected]:/etc/kubernetes

[root@k8s-master1 ~]# scp /etc/kubernetes/pki/{ca.*,sa.*,front-proxy-ca.*} [email protected]:/etc/kubernetes/pki
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/{ca.*,sa.*,front-proxy-ca.*} [email protected]:/etc/kubernetes/pki

[root@k8s-master1 ~]# scp /etc/kubernetes/pki/etcd/ca.* [email protected]:/etc/kubernetes/pki/etcd
[root@k8s-master1 ~]# scp /etc/kubernetes/pki/etcd/ca.* [email protected]:/etc/kubernetes/pki/etcd

将其他master节点加入集群

注意：kubeadm init生成的token有效期只有1天，生成不过期token

[root@k8s-master1 ~]# kubeadm token create --ttl 0 --print-join-command
kubeadm join master.k8s.io:6443 --token 4vd7c0.x8z96hhh4808n4fv     --discovery-token-ca-cert-hash sha256:20a551796d33309f20ad7579c710ea766ef39b64b98c37a4a4029a903f23300a 

[root@k8s-master1 ~]#  kubeadm token list
TOKEN                     TTL         EXPIRES   USAGES                   DESCRIPTION                                                EXTRA GROUPS
p9u7gb.o9naimgqjauiuzr6         authentication,signing                                                        system:bootstrappers:kubeadm:default-node-token
xhfagw.6wkdnkdrd2rhkbe9   23h         2023-08-16T14:03:32+08:00   authentication,signing                                                        system:bootstrappers:kubeadm:default-node-token

k8s-master2和k8s-master3都需要加入

[root@k8s-master3 master]#  kubeadm join master.k8s.io:6443 --token zus2jc.brtsxszpyv03a57j     --discovery-token-ca-cert-hash sha256:20a551796d33309f20ad7579c710ea766ef39b64b98c37a4a4029a903f23300a     --control-plane 
 
[preflight] Running pre-flight checks
	[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
	[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 24.0.5. Latest validated version: 19.03
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...

This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.

Run 'kubectl get nodes' on the control-plane to see this node join the cluster.


[root@k8s-master3 master]#   mkdir -p $HOME/.kube
[root@k8s-master3 master]#   sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-master3 master]#   sudo chown $(id -u):$(id -g) $HOME/.kube/config

如果master2/3加入时报错

1. [ERROR FileAvailable--etc-kubernetes-pki-ca.crt]: /etc/kubernetes/pki/ca.crt already exists 是一个错误消息，表示 /etc/kubernetes/pki/ca.crt 文件已经存在

直接删除改文件，在执行命令即可

[root@k8s-master2 master]# rm -rf /etc/kubernetes/pki/ca.crt

master2/3添加cni

[root@k8s-master3 master]# tar -xf cni-plugins-linux-amd64-v0.8.6.tgz 
[root@k8s-master3 master]# rz -E
rz waiting to receive.
[root@k8s-master3 master]# cp flannel /opt/cni/bin/
[root@k8s-master3 master]# kubectl apply -f kube-flannel.yml
podsecuritypolicy.policy/psp.flannel.unprivileged configured
Warning: rbac.authorization.k8s.io/v1beta1 ClusterRole is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io/v1 ClusterRole
clusterrole.rbac.authorization.k8s.io/flannel unchanged
Warning: rbac.authorization.k8s.io/v1beta1 ClusterRoleBinding is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io/v1 ClusterRoleBinding
clusterrolebinding.rbac.authorization.k8s.io/flannel unchanged
serviceaccount/flannel unchanged
configmap/kube-flannel-cfg unchanged
daemonset.apps/kube-flannel-ds-amd64 unchanged
daemonset.apps/kube-flannel-ds-arm64 unchanged
daemonset.apps/kube-flannel-ds-arm unchanged
daemonset.apps/kube-flannel-ds-ppc64le unchanged
daemonset.apps/kube-flannel-ds-s390x unchanged

master1查看nodes

[root@k8s-master1 ~]# kubectl get nodes
NAME          STATUS   ROLES                  AGE     VERSION
k8s-master1   Ready    control-plane,master   8m14s   v1.20.0
k8s-master2   Ready    control-plane,master   48s     v1.20.0
k8s-master3   Ready    control-plane,master   13s     v1.20.0

3.9、加入Kubernetes Node

直接在node节点服务器上执行k8s-master1初始化成功后的消息即可：

[root@k8s-node3 ~]# kubeadm join master.k8s.io:6443 --token zus2jc.brtsxszpyv03a57j \
>     --discovery-token-ca-cert-hash sha256:20a551796d33309f20ad7579c710ea766ef39b64b98c37a4a4029a903f23300a

[root@k8s-node1 ~]# docker load < flannel_v0.12.0-amd64.tar
Loaded image: quay.io/coreos/flannel:v0.12.0-amd64

添加cni 同master操作

 查看节点信息

[root@k8s-master1 demo]# kubectl get nodes
NAME          STATUS   ROLES                  AGE   VERSION
k8s-master1   Ready    control-plane,master   45m   v1.20.0
k8s-master2   Ready    control-plane,master   37m   v1.20.0
k8s-master3   Ready    control-plane,master   37m   v1.20.0
k8s-node1     Ready                     32m   v1.20.0
k8s-node2     Ready                     31m   v1.20.0
k8s-node3     Ready                     31m   v1.20.0

3.10、测试Kubernetes集群

所有node主机导入测试镜像

[root@k8s-node1 ~]# docker load < nginx-1.19.tar 
[root@k8s-node1 ~]# docker tag nginx nginx:1.19.6

在Kubernetes集群中创建一个pod，验证是否正常运行。

[root@k8s-master1 ~]# mkdir demo
[root@k8s-master1 ~]# cd demo
[root@k8s-master1 demo]# vim nginx-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector: 
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.19.6
        ports:
        - containerPort: 80

创建完 Deployment 的资源清单之后，使用 create 执行资源清单来创建容器。通过 get pods 可以查看到 Pod 容器资源已经自动创建完成。

[root@k8s-master1 demo]# kubectl create -f nginx-deployment.yaml
deployment.apps/nginx-deployment created

[root@k8s-master1 demo]# kubectl get pods
NAME                                READY   STATUS              RESTARTS   AGE
nginx-deployment-76ccf9dd9d-dhcl8   1/1     Running             0          11m
nginx-deployment-76ccf9dd9d-psn8p   1/1     Running             0          11m
nginx-deployment-76ccf9dd9d-xllhp   1/1     Running             0          11m

[root@k8s-master1 demo]# kubectl get pods -o wide
NAME                                READY   STATUS    RESTARTS   AGE     IP           NODE        NOMINATED NODE   READINESS GATES
nginx-deployme-596f5df7f-8mhzz      1/1     Running   0          5m10s   10.244.4.4   k8s-node3              
nginx-deployme-596f5df7f-ql7l7      1/1     Running   0          5m10s   10.244.4.3   k8s-node3              
nginx-deployme-596f5df7f-x6pgv      1/1     Running   0          5m10s   10.244.4.2   k8s-node3              

创建Service资源清单

在创建的 nginx-service 资源清单中，定义名称为 nginx-service 的 Service、标签选择器为 app: nginx、type 为 NodePort 指明外部流量可以访问内部容器。在 ports 中定义暴露的端口库号列表，对外暴露访问的端口是 80，容器内部的端口也是 80。

[root@k8s-master1 demo]# vim nginx-service.yaml
kind: Service
apiVersion: v1
metadata:
  name: nginx-service
spec:
  selector:
    app: nginx
  type: NodePort
  ports:
  - protocol: TCP
    port: 80
targetPort: 80

[root@k8s-master1 demo]# kubectl create -f nginx-service.yaml 
service/nginx-service created
[root@k8s-master1 demo]# kubectl get svc
NAME            TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)        AGE
kubernetes      ClusterIP   10.1.0.1              443/TCP        52m
nginx-service   NodePort    10.1.39.231           80:31418/TCP   14s
[root@k8s-master1 demo]# 

通过浏览器访问nginx：http://master.k8s.io:31418 域名或者VIP地址

[root@k8s-master1 demo]#  elinks --dump http://master.k8s.io:31418
                               Welcome to nginx!

   If you see this page, the nginx web server is successfully installed and
   working. Further configuration is required.

   For online documentation and support please refer to [1]nginx.org.
   Commercial support is available at [2]nginx.com.

   Thank you for using nginx.

References

   Visible links
   1. http://nginx.org/
   2. http://nginx.com/

 

挂起k8s-master1节点，刷新页面还是能访问nginx，说明高可用集群部署成功。

 

 

检查会发现VIP已经转移到k8s-master2节点上

[root@k8s-master2 master]# ip a s ens33
2: ens33:  mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:ae:1d:c6 brd ff:ff:ff:ff:ff:ff
    inet 192.168.147.139/24 brd 192.168.147.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.147.154/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::bd67:1ba:506d:b021/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::146a:2496:1fdc:4014/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::5d98:c5e3:98f8:181/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

至此Kubernetes企业级高可用环境完美实现。

4、项目总结

1、集群中只要有一个master节点正常运行就可以正常对外提供业务服务。

2、如果需要在master节点使用kubectl相关的命令，必须保证至少有2个master节点正常运行才可以使用，不然会有 Unable to connect to the server: net/http: TLS handshake timeout 这样的错误。

3、Node节点故障时pod自动转移：当pod所在的Node节点宕机后，根据 controller-manager的–pod-eviction-timeout 配置，默认是5分钟，5分钟后k8s会把pod状态设置为unkown， 然后在其它节点启动pod。当故障节点恢复后，k8s会删除故障节点上面的unkown pod。如果你想立即强制迁移，可以用 kubectl drain nodename

4、为了保证集群的高可用性，建议master节点和node节点至少分别部署3台及以上，且master节点应该部署基数个实例(3、5、7、9)。