03 CenterOS7.9 安装K8s过程
2021-10-17 本文已影响0人
逸章
一、主机环境准备
1、主机名配置
1.1 三台主机上各自修改自己主机名
hostnamectl set-hostname k8s-master
hostnamectl set-hostname k8s-node1
hostnamectl set-hostname k8s-node2
1.2 三台主机上配置host文件，把work和node节点都加进去
#配置hosts文件
cat >> /etc/hosts << EOF
192.168.100.48 k8s-master
192.168.100.49 k8s-node01
192.168.100.50 k8s-node02
EOF
2、在三台机器上关闭防火墙等
防火墙等禁用
systemctl stop firewalld
systemctl disable firewalld
setenforce 0
sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config
swapoff -a #关闭swap交换分区
sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab #禁止swap交换分区开机自启
#合一为：
#systemctl stop firewalld && systemctl disable firewalld && setenforce 0 && sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config && swapoff -a && sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
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
sysctl --system #使上一条命令的配置生效
NTP时间同步
yum install -y ntpdate #安装ntpdate用于校准时间,确保master和node时间同步
ntpdate time.windows.com #校准时间
二、在三台机器上都安装Docker
yum install wget -y
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-20.10.9
#以下命令用来配置镜像地址..
curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s http://f1361db2.m.daocloud.io
systemctl enable docker
systemctl start docker
附：删除已经安装的Docker方法为：
[root@k8s-master ~]# yum list installed|grep docker containerd.io.x86_64 1.4.11-3.1.el7 @docker-ce-stable docker.x86_64 2:1.13.1-208.git7d71120.el7_9 @extras docker-client.x86_64 2:1.13.1-208.git7d71120.el7_9 @extras docker-common.x86_64 2:1.13.1-208.git7d71120.el7_9 @extras [root@k8s-master ~]# yum -y remove containerd.io.x86_64 docker.x86_64 docker-client.x86_64 docker-common.x86_64
三、三台主机都安装K8s
配置国内k8s镜像地址
k8s镜像仓库需要翻出去,所以配置国内镜像地址
[root@k82-node2 ~]# 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
安装K8s（安装和使能kubelet）
[root@k82-node2 ~]# yum install -y kubelet-1.15.0 kubeadm-1.15.0 kubectl-1.15.0
...
Installed:
kubeadm.x86_64 0:1.15.0-0 kubectl.x86_64 0:1.15.0-0 kubelet.x86_64 0:1.15.0-0
Dependency Installed:
conntrack-tools.x86_64 0:1.4.4-7.el7 cri-tools.x86_64 0:1.13.0-0 kubernetes-cni.x86_64 0:0.8.7-0
libnetfilter_cthelper.x86_64 0:1.0.0-11.el7 libnetfilter_cttimeout.x86_64 0:1.0.0-7.el7 libnetfilter_queue.x86_64 0:1.0.2-2.el7_2
socat.x86_64 0:1.7.3.2-2.el7
Complete!
[root@k82-node2 ~]# systemctl enable kubelet
附：既有K8s的删除方法：
[root@k8s-node-88 ~]# yum list installed|grep kube cri-tools.x86_64 1.19.0-0 @kubernetes kubeadm.x86_64 1.22.2-0 @kubernetes kubectl.x86_64 1.22.2-0 @kubernetes kubelet.x86_64 1.22.2-0 @kubernetes kubernetes-cni.x86_64 0.8.7-0 @kubernetes [root@k8s-node-88 ~]# yum -y remove cri-tools.x86_64 kubeadm.x86_64 kubectl.x86_64 kubelet.x86_64 kubernetes-cni.x86_64
配置cgroupdriver=systemd
默认docker的Cgroup是cgroups，kubelet的Cgroups是systemd，两者的Cgroups不一样，两边需要修改成一致的配置
[root@k8s-master-86 ~]# cat /etc/docker/daemon.json
{
"registry-mirrors": [
"http://f1361db2.m.daocloud.io",
"https://registry.docker-cn.com",
"https://hub-mirror.c.163.com",
"https://docker.mirrors.ustc.edu.cn" ],
"exec-opts": ["native.cgroupdriver=systemd"]
}
[root@k8s-master-86 ~]# cat > /var/lib/kubelet/config.yaml <<EOF
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
cgroupDriver: systemd
EOF
[root@k8s-master-86 ~]# systemctl daemon-reload && \
systemctl restart docker && \
systemctl restart kubelet
四、创建K8s集群
1、仅在master节点上执行
1.1 初始化
kubeadm init \
--apiserver-advertise-address=192.168.100.48 \
--image-repository registry.aliyuncs.com/google_containers \
--kubernetes-version v1.15.0 \
--service-cidr=10.1.0.0/16 \
--pod-network-cidr=10.244.0.0/16
image.png
然后依据提示执行:
[root@k8s-master ~]# mkdir -p $HOME/.kube && \
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config && \
sudo chown $(id -u):$(id -g) $HOME/.kube/config
上面的命令如果不执行，则在执行kubectl get node时会得到下面的提示：image.png
初始化如果失败，请执行
rm -rf /var/lib/etcd && \ rm -rf /etc/kubernetes/* && \ rm -rf ~/.kube/* &&\ echo y | kubeadm reset
然后重新初始化
1.2 在master节点安装配置flannel网络
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
kubectl apply -f kube-flannel.yml
然后检查健康状况：
[root@k8s-master-86 ~]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-7f6cbbb7b8-9l2mt 1/1 Running 0 26m
coredns-7f6cbbb7b8-jl2qm 1/1 Running 0 26m
etcd-k8s-master-86 1/1 Running 1 26m
kube-apiserver-k8s-master-86 1/1 Running 1 26m
kube-controller-manager-k8s-master-86 1/1 Running 1 26m
kube-flannel-ds-clldj 1/1 Running 0 11m
kube-proxy-shxg5 1/1 Running 0 26m
kube-scheduler-k8s-master-86 1/1 Running 1 26m
[root@k8s-master-86 ~]# 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 Healthy ok
etcd-0 Healthy {"health":"true","reason":""}
[root@k8s-master-86 ~]# ps -ef|grep flannel|grep -v grep #可能需要10分钟左右启动初始化完成,才有返回结果.然后再执行下一步
[root@k8s-master-86 ~]# kubectl get nodes #可能需要等待十几分钟,状态才能全部转为ready.然后再执行下一步
上面kubectl get cs结果显示系统不健康，解决方案如下：
把下面文件的 - --port=0注释掉，即前面加上#
# vi /etc/kubernetes/manifests/kube-controller-manager.yaml
# vi /etc/kubernetes/manifests/kube-scheduler.yaml
# systemctl restart kubelet.service
image.png
我自己下载了kube-flannel.yml文件，然后进行了局部修改
wget https://raw.githubusercontent.com/coreos/flannel/a70459be0084506e4ec919aa1c114638878db11b/Documentation/kube-flannel.yml
vi kube-flannel.yml
修改kube-flannel.yml里面为(vi中使用:set number，然后 :106定位到106行)：
第106行为 image: lizhenliang/flannel:v0.11.0-amd64
第120行为 image: lizhenliang/flannel:v0.11.0-amd64
image.png
注意，你可能会遇到有一个node节点是NotReady的问题：image.png
可能是NotReady节点没有自动下载flannel这个docker镜像，验证过程如下：image.png 比如另外一个node就是Ready状态，它下载的镜像如下：
image.png
进一步分析发现这台node什么镜像都下载不下来：
image.png
图中给出了解决方法，修改/etc/docker/daemon.json里面内容，换用一个新的国内镜像源，最后成功了
2、仅在两个node节点上执行
注意，命令来自master节点init执行结果中给出的加入集群提示
[root@k8s-node2 ~]# kubeadm join 192.168.100.48:6443 --token qgg72c.up6e96wieswtdod1 \
> --discovery-token-ca-cert-hash
......
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-node2 ~]#
如果后期有node想加入，但是又不知道token，可以如下操作生成一个新的token后依据提示加入集群：
[root@k8s-master03 wal]# kubeadm token create --print-join-command kubeadm join 192.168.108.222:6443 --token pduv8e.dc5z5iu84f8lyrfh --discovery-token-ca-cert-hash > sha256:44bb94c467bdcaa79d3128af9872c1296757f993e404e1751e1662c7de3faddb若是想增加master，别忘记了加上--control-plane，后面高可用部分会提到多master方案
五、简单测试一下nginx的K8s部署（非必须）
[root@k8s-master ~]# kubectl create deployment nginx --image=nginx
[root@k8s-master ~]# kubectl expose deployment nginx --port=80 --type=NodePort
[root@k8s-master ~]# kubectl get pods,svc
NAME READY STATUS RESTARTS AGE
pod/nginx-554b9c67f9-2xwhw 1/1 Running 0 43s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.1.0.1 <none> 443/TCP 28h
service/nginx NodePort 10.1.170.52 <none> 80:30385/TCP 24s
[root@k8s-master ~]#
image.png
image.png
1、扩缩容测试
1.1、扩容，要求有两个nginx实例在运行
[root@k8s-master ~]# kubectl scale deployment nginx --replicas=2
image.png
1.1、缩容，从4个实例缩为2个nginx实例
[root@k8s-master ~]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-554b9c67f9-jhkgt 1/1 Running 0 15m 10.244.1.7 k8s-node2 <none> <none>
nginx-554b9c67f9-qchcx 1/1 Running 1 15m 10.244.2.12 k8s-node1 <none> <none>
[root@k8s-master ~]# kubectl scale deployment nginx --replicas=4
deployment.extensions/nginx scaled
[root@k8s-master ~]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-554b9c67f9-jhkgt 1/1 Running 0 15m 10.244.1.7 k8s-node2 <none> <none>
nginx-554b9c67f9-qchcx 1/1 Running 1 15m 10.244.2.12 k8s-node1 <none> <none>
nginx-554b9c67f9-vns7w 1/1 Running 0 3s 10.244.2.14 k8s-node1 <none> <none>
nginx-554b9c67f9-zs27t 1/1 Running 0 3s 10.244.1.9 k8s-node2 <none> <none>
[root@k8s-master ~]# kubectl scale deployment nginx --replicas=3
deployment.extensions/nginx scaled
[root@k8s-master ~]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-554b9c67f9-jhkgt 1/1 Running 0 15m 10.244.1.7 k8s-node2 <none> <none>
nginx-554b9c67f9-qchcx 1/1 Running 1 15m 10.244.2.12 k8s-node1 <none> <none>
nginx-554b9c67f9-vns7w 1/1 Running 0 14s 10.244.2.14 k8s-node1 <none> <none>
nginx-554b9c67f9-zs27t 0/1 Terminating 0 14s 10.244.1.9 k8s-node2 <none> <none>
[root@k8s-master ~]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-554b9c67f9-jhkgt 1/1 Running 0 15m 10.244.1.7 k8s-node2 <none> <none>
nginx-554b9c67f9-qchcx 1/1 Running 1 16m 10.244.2.12 k8s-node1 <none> <none>
nginx-554b9c67f9-vns7w 1/1 Running 0 40s 10.244.2.14 k8s-node1 <none> <none>
[root@k8s-master ~]#
image.png
2、高可用测试
接下来我们分别尝试删除pod和停止Container来测试高可用性：
[root@k8s-master ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-554b9c67f9-2xwhw 1/1 Running 0 18h
nginx-554b9c67f9-qchcx 1/1 Running 0 23s
[root@k8s-master ~]# kubectl delete pod nginx-554b9c67f9-2xwhw
pod "nginx-554b9c67f9-2xwhw" deleted
[root@k8s-master ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-554b9c67f9-jhkgt 1/1 Running 0 15s
nginx-554b9c67f9-qchcx 1/1 Running 0 51s
[root@k8s-master ~]# ssh k8s-node1
root@k8s-node1's password:
Last login: Wed Oct 20 06:15:25 2021 from k8s-master
[root@k8s-node1 ~]# docker ps | grep nginx
f15ab7d492b3 nginx "/docker-entrypoint.…" 2 minutes ago Up 2 minutes k8s_nginx_nginx-554b9c67f9-qchcx_default_5553e8b9-a20a-48c6-a0b5-bb514fb59fcc_0
a9a0506fa724 registry.aliyuncs.com/google_containers/pause:3.1 "/pause" 2 minutes ago Up 2 minutes k8s_POD_nginx-554b9c67f9-qchcx_default_5553e8b9-a20a-48c6-a0b5-bb514fb59fcc_0
[root@k8s-node1 ~]# docker stop f15ab7d492b3
f15ab7d492b3
[root@k8s-node1 ~]# docker ps | grep nginx
5b809693112f nginx "/docker-entrypoint.…" 6 seconds ago Up 5 seconds k8s_nginx_nginx-554b9c67f9-qchcx_default_5553e8b9-a20a-48c6-a0b5-bb514fb59fcc_1
a9a0506fa724 registry.aliyuncs.com/google_containers/pause:3.1 "/pause" 2 minutes ago Up 2 minutes k8s_POD_nginx-554b9c67f9-qchcx_default_5553e8b9-a20a-48c6-a0b5-bb514fb59fcc_0
[root@k8s-node1 ~]# exit
logout
Connection to k8s-node1 closed.
[root@k8s-master ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-554b9c67f9-jhkgt 1/1 Running 0 2m40s
nginx-554b9c67f9-qchcx 1/1 Running 1 3m16s
[root@k8s-master ~]#
image.png
六、配置k8s UI界面（非必须）
1、安装
[root@k8s-master ~]# wget https://raw.githubusercontent.com/kubernetes/dashboard/v1.10.1/src/deploy/recommended/kubernetes-dashboard.yaml
--2021-10-20 03:20:43-- https://raw.githubusercontent.com/kubernetes/dashboard/v1.10.1/src/deploy/recommended/kubernetes-dashboard.yaml
Resolving raw.githubusercontent.com (raw.githubusercontent.com)... 185.199.111.133, 185.199.110.133, 185.199.109.133, ...
Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|185.199.111.133|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 4577 (4.5K) [text/plain]
Saving to: ‘kubernetes-dashboard.yaml’
100%[==============================================================================================================>] 4,577 --.-K/s in 0.002s
2021-10-20 03:20:43 (2.33 MB/s) - ‘kubernetes-dashboard.yaml’ saved [4577/4577]
[root@k8s-master ~]# vi kubernetes-dashboard.yaml
[root@k8s-master ~]# kubectl apply -f kubernetes-dashboard.yaml
secret/kubernetes-dashboard-certs created
serviceaccount/kubernetes-dashboard created
role.rbac.authorization.k8s.io/kubernetes-dashboard-minimal created
rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard-minimal created
deployment.apps/kubernetes-dashboard created
service/kubernetes-dashboard created
[root@k8s-master ~]#
修改内容为：
112行 image: lizhenliang/kubernetes-dashboard-amd64:v1.10.1 # 替换为此
158行 type: NodePort # 增加此行
162行 nodePort: 30001 # 增加此行
image.png
image.png
2、配置管理员账号(注意产生的token)
[root@k8s-master ~]# kubectl create serviceaccount dashboard-admin -n kube-system
serviceaccount/dashboard-admin created
[root@k8s-master ~]# kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
clusterrolebinding.rbac.authorization.k8s.io/dashboard-admin created
[root@k8s-master ~]# kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
Name: dashboard-admin-token-xnv89
Namespace: kube-system
Labels: <none>
Annotations: kubernetes.io/service-account.name: dashboard-admin
kubernetes.io/service-account.uid: ee729a1d-691a-4fee-899e-968cd8622fb5
Type: kubernetes.io/service-account-token
Data
====
ca.crt: 1025 bytes
namespace: 11 bytes
token: eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.Gt9TpRex7_Z7-fsrmMns_ijVzkEoFdUWEOHR-6R5ui0kOGTAjILCnxKqF2FrJPwp0R593cgnOOa_ygvC1ljUE69bw4HX-MCVQzf3f1WPPoLiR_ToXpQfVtUJq7FLir-46WmygStD2VWDb8auQuCIOiKyC1c1-JR6GwYTpQ55-gQoF7Orp4ijQaOjuKrKnmINrNtwAMzOZvyn2CIg7eIZ6ARk9_iv_xhUW4LBWdrkTaH5a4NR1C3yvlf5z2AaI549LJaYAP-DhS28Nb-PpqMfJxj38RJW0nPHwEOVrxe5xUgK6fPj_KJWwjb7JxG9cujHdrKjoXjdAximM90xvlMaVw
[root@k8s-master ~]#
3、登录
用firefox浏览器访问：访问https://192.168.2.130:30001
image.png
image.png
七、master节点的高可用和负载均衡（商用环境需要使用高可用）
使用keepalived+haproxy方案，
1、keepalive本身是没有负载均衡能力的，它只是提供主机高可用的能力的；
2、此处的haproxy为apiserver提供反向代理，haproxy将所有请求轮询转发到每个master节点上。在仅仅使用keepalived主备模式下仅单个master节点承载流量，而配备了haproxy后系统具有更高的吞吐量。
7.1、一共3个k8s-master节点
一共有3个Master：
master：192.168.108.88 k8s-master03
backup：192.168.108.87 k8s-master02
backup：192.168.108.86 k8s-master04
二个worker节点：
k8s-node1：192.168.100.49
k8s-node2：192.168.100.50
# hostnamectl set-hostname k8s-master02
# hostnamectl set-hostname k8s-master03
# hostnamectl set-hostname k8s-master04
# hostnamectl set-hostname k8s-node1
# hostnamectl set-hostname k8s-node2
7.2、修改所有节点的/etc/hosts文件
image.png
7.3、所有master间的免密钥登陆
各个master把自己公钥发到同一个master上汇总（这里选用k8s-master01），然后分发到各个master上：
[root@k8s-master03 ~]# ssh-keygen -t dsa -P '' -f ~/.ssh/id_dsa && cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys && ssh-copy-id -i ~/.ssh/id_dsa.pub k8s-master
接下来把汇总的公钥分发给其他master主机（k8s-master02和k8s-master03）：
[root@k8s-master01 ~]# scp -r /root/.ssh/authorized_keys root@k8s-master02:/root/.ssh/
[root@k8s-master01 ~]# scp -r /root/.ssh/authorized_keys root@192.168.108.88:/root/.ssh/
到各个master上修改文件访问权限：
[root@k8s-master03 ~]# chmod 600 ~/.ssh/authorized_keys
[root@k8s-master02 ~]# chmod 600 ~/.ssh/authorized_keys
7.4、在所有master节点上安装keepalive和haproxy
7.4.1、安装keepalive和haproxy
# yum install -y socat keepalived haproxy ipvsadm conntrack
7.4.2、配置keepalive属性（修改/etc/keepalived/keepalived.conf）
本例中环境：
master：192.168.108.88
backup：192.168.108.87
backup：192.168.108.86
VIP： 192.168.108.100
# vi /etc/keepalived/keepalived.conf
各个master节点依据自己情况做少量更改，主要是：
1、自己的被选举权重
2、自己的网卡名称
在本例中，主master节点配置（/etc/keepalived/keepalived.conf）为：
global_defs{
router_id master01
}
vrrp_instance VI_1 {
state MASTER #主
interface ens160 #网卡名字，根据自己实际的网卡名称来写, 你可以通过# ip addr来查看
virtual_router_id 50 #ID是唯一的，必须一致
priority 100 #权重100 ，根据权重来选举虚拟ip，其他两台权重不能一样
advert_int 1
authentication { #认证方式，必须统一密码
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.108.222 #vip 创建一个虚拟IP
}
track_script {
check_apiserver
}
}
第一个备份master节点配置（/etc/keepalived/keepalived.conf）：
global_defs {
router_id master01
}
vrrp_instance VI_1 {
state BACKUP
interface ens160
virtual_router_id 50
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.108.222
}
track_script {
check_apiserver
}
}
第二个备份master节点配置为（/etc/keepalived/keepalived.conf）：
global_defs {
router_id master01
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 50
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.108.222
}
track_script {
check_apiserver
}
}
7.4.3、配置haproxy属性（修改/etc/haproxy/haproxy.cfg）
三个节点都一样的配置
image.png
#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
log /dev/log local0
log /dev/log local1 notice
daemon
#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use 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 1
timeout http-request 10s
timeout queue 20s
timeout connect 5s
timeout client 20s
timeout server 20s
timeout http-keep-alive 10s
timeout check 10s
#---------------------------------------------------------------------
# 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
http-check expect status 200
mode tcp
option ssl-hello-chk
balance roundrobin
server master02 192.168.108.87:6443 check
server master03 192.168.108.88:6443 check
server master04 192.168.108.86:6443 check
7.4.4、可以测试一下keepalived是否起作用
image.png
7.5、所有master上都启动keepalive服务和haproxy服务
注意：如果你的master之前执行过kubeadm init，则需要执行kubeadm reset，然后再启动keepalive
# systemctl enable keepalived && systemctl start keepalived
# systemctl status keepalived
# systemctl enable haproxy && systemctl start haproxy
# systemctl status haproxy
主Master上看到的
从第一个Master上看到的
从第二个Master上看到的
haproxy的状态：
第一个master上看到的
另外一个master上看到的
7.6、在所有master上启用IPVS（可选的，一般可以不用配置）
# cat > /etc/sysconfig/modules/ipvs.modules <<EOF
#!/bin/bash
ipvs_modules="ip_vs ip_vs_lc ip_vs_wlc ip_vs_rr ip_vs_wrr ip_vs_lblc ip_vs_lblcr ip_vs_dh ip_vs_sh ip_vs_fo ip_vs_nq ip_vs_sed ip_vs_ftp nf_conntrack"
for kernel_module in \${ipvs_modules}; do
/sbin/modinfo -F filename \${kernel_module} > /dev/null 2>&1
if [ $? -eq 0 ]; then
/sbin/modprobe \${kernel_module}
fi
done
EOF
# chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep ip_vs
7.7、配置K8s
仿造前面做node和master的配置（master到初始化master的前一步）这里略去，参考前面即可
7.8、在一个master上进行初始化
7.8.1、在一个master上配置一下/etc/kubernetes/kubeadm-config.yaml
apiVersion: kubeadm.k8s.io/v1beta1
kind: ClusterConfiguration
kubernetesVersion: v1.15.0
controlPlaneEndpoint: "192.168.108.222:6443"
apiServer:
certSANs:
- 192.168.108.222
- 192.168.108.88
- 192.168.108.87
- 192.168.108.86
networking:
podSubnet: 10.244.0.0/16
imageRepository: "registry.aliyuncs.com/google_containers"
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs
7.8.2、在同一个master上执行init
鉴于我们是在非master高可用基础上做的高可用，即原来的master上曾经执行过kubeadm init，所以这里需要在这个节点上先执行reset操作(只需要在原来的那一个master节点上执行即可)
[root@k8s-master03 ~]# kubeadm reset && \
rm -rf /var/lib/etcd && \
rm -rf /etc/kubernetes/* && \
rm -rf ~/.kube/*
[root@k8s-master03 ~]# iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X
[root@k8s-master03 ~]# systemctl stop kubelet && \
systemctl stop docker && \
rm -rf /var/lib/cni/* && \
rm -rf /var/lib/kubelet/* && \
rm -rf /etc/cni/* && \
systemctl start docker && \
systemctl start kubelet
[root@k8s-master03 ~]# kubeadm init --config /etc/kubernetes/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
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 192.168.108.222:6443 --token t3l781.rf2tc20q312xi6hb \
--discovery-token-ca-cert-hash sha256:348f4b1c3f458a70b96674da3d0d5d4fead1f79a6a0f2cf83261a4518b093695 \
--experimental-control-plane
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 192.168.108.222:6443 --token t3l781.rf2tc20q312xi6hb \
--discovery-token-ca-cert-hash sha256:348f4b1c3f458a70b96674da3d0d5d4fead1f79a6a0f2cf83261a4518b093695
# mkdir -p $HOME/.kube && sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config && sudo chown $(id -u):$(id -g) $HOME/.kube/config
7.9、从MASTER拷贝证书到其他BACKUP的master节点上（很重要）
在MASTER上建一个脚本然后执行：
[root@k8s-master03 ~]# vi cert-master.sh
[root@k8s-master03 ~]# cat cert-master.sh
USER=root # customizable
CONTROL_PLANE_IPS="192.168.108.87 192.168.100.48"
for host in ${CONTROL_PLANE_IPS}; do
scp /etc/kubernetes/pki/ca.crt "${USER}"@$host:
scp /etc/kubernetes/pki/ca.key "${USER}"@$host:
scp /etc/kubernetes/pki/sa.key "${USER}"@$host:
scp /etc/kubernetes/pki/sa.pub "${USER}"@$host:
scp /etc/kubernetes/pki/front-proxy-ca.crt "${USER}"@$host:
scp /etc/kubernetes/pki/front-proxy-ca.key "${USER}"@$host:
scp /etc/kubernetes/pki/etcd/ca.crt "${USER}"@$host:etcd-ca.crt
# Quote this line if you are using external etcd
scp /etc/kubernetes/pki/etcd/ca.key "${USER}"@$host:etcd-ca.key
done
[root@k8s-master03 ~]# sh cert-master.sh
ca.crt 100% 1025 1.8MB/s 00:00
ca.key 100% 1679 3.4MB/s 00:00
sa.key 100% 1675 2.9MB/s 00:00
sa.pub 100% 451 942.8KB/s 00:00
front-proxy-ca.crt 100% 1038 2.6MB/s 00:00
front-proxy-ca.key 100% 1679 3.9MB/s 00:00
ca.crt 100% 1017 1.9MB/s 00:00
ca.key 100% 1675 2.2MB/s 00:00
ca.crt 100% 1025 48.8KB/s 00:00
ca.key 100% 1679 1.5MB/s 00:00
sa.key 100% 1675 1.3MB/s 00:00
sa.pub 100% 451 463.5KB/s 00:00
front-proxy-ca.crt 100% 1038 176.0KB/s 00:00
front-proxy-ca.key 100% 1679 600.6KB/s 00:00
ca.crt 100% 1017 878.1KB/s 00:00
ca.key 100% 1675 1.5MB/s 00:00
[root@k8s-master03 ~]#
在所有其他的BACKUP master上建一个脚本然后执行：
[root@k8s-master01 ~]# cat mv-cert.sh
USER=root # customizable
mkdir -p /etc/kubernetes/pki/etcd
mv /${USER}/ca.crt /etc/kubernetes/pki/
mv /${USER}/ca.key /etc/kubernetes/pki/
mv /${USER}/sa.pub /etc/kubernetes/pki/
mv /${USER}/sa.key /etc/kubernetes/pki/
mv /${USER}/front-proxy-ca.crt /etc/kubernetes/pki/
mv /${USER}/front-proxy-ca.key /etc/kubernetes/pki/
mv /${USER}/etcd-ca.crt /etc/kubernetes/pki/etcd/ca.crt
# Quote this line if you are using external etcd
mv /${USER}/etcd-ca.key /etc/kubernetes/pki/etcd/ca.key
[root@k8s-master01 ~]# sh mv-cert.sh
[root@k8s-master02 ~]# cat mv-cert.sh
USER=root # customizable
mkdir -p /etc/kubernetes/pki/etcd
mv /${USER}/ca.crt /etc/kubernetes/pki/
mv /${USER}/ca.key /etc/kubernetes/pki/
mv /${USER}/sa.pub /etc/kubernetes/pki/
mv /${USER}/sa.key /etc/kubernetes/pki/
mv /${USER}/front-proxy-ca.crt /etc/kubernetes/pki/
mv /${USER}/front-proxy-ca.key /etc/kubernetes/pki/
mv /${USER}/etcd-ca.crt /etc/kubernetes/pki/etcd/ca.crt
# Quote this line if you are using external etcd
mv /${USER}/etcd-ca.key /etc/kubernetes/pki/etcd/ca.key
[root@k8s-master02 ~]# sh mv-cert.sh
7.10、剩余的master节点通过kubeadm join加入集群
其他的master backup节点都需要执行：
[root@k8s-master02 ~]# kubeadm join 192.168.108.222:6443 --token 711yyq.kauqnz8sbpqy5mck --discovery-token-ca-cert-hash sha256:ba3cd3361994078d2d48634e1ec2fca64b95135460c4be1f64d3fd220721b8a9 --control-plane
......
This node has joined the cluster and a new control plane instance was created:
* Certificate signing request was sent to apiserver and approval was received.
* The Kubelet was informed of the new secure connection details.
* Control plane (master) label and taint were applied to the new node.
* The Kubernetes control plane instances scaled up.
* A new etcd member was added to the local/stacked etcd cluster.
To start administering your cluster from this node, 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
Run 'kubectl get nodes' to see this node join the cluster.
[root@k8s-master02 ~]# mkdir -p $HOME/.kube && sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config && sudo chown $(id -u):$(id -g) $HOME/.kube/config
kubeadm join 可以加上参数--v=2 来打印日志
token信息可以在主master上执行kubeadm token list来查看
join过程如果看到[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd"这样的警告信息，如果你想解决，可以如下图：image.png
7.11、重新安装一下网络插件flannel
参考前面方法在每个节点上都重新安装一次即可（如果不装会出现kube-flannel.yml）
# kubectl apply -f kube-flannel.yml #kube-flannel.yml的下载和内容修改见前文
如果有一个master没有安装，则最后在使用kubectl get node的时候会发现节点状态是NotReady
进一步执行kubectl describe node时会显示network plugin is not ready: cni config uninitialized
说明：我遇到过一个错误，上一次有个节点已经配置了一个不同的keepalive集群，在执行过程中有错误，提示不能连接的一个ip上上一个集群的VIP，这个时候你可以试一下下面的操作
# kubeadm init --config /etc/kubernetes/kubeadm-config.yaml # mkdir -p $HOME/.kube # sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config # sudo chown $(id -u):$(id -g) $HOME/.kube/config # kubectl apply -f kube-flannel.yml 下面的是为后面的join准备的 # kubeadm reset # rm -rf /var/lib/etcdetcd的数据会挂载到master节点/var/lib/etcd
7.12、所有node节点通过kubeadm join加入集群
在每个node上都执行（如果node曾经join过别的集群，需要执行kubeadm reset）
[root@k8s-node1 ~]# kubeadm reset
[root@k8s-node1 ~]# kubeadm join 192.168.108.222:6443 --token 711yyq.kauqnz8sbpqy5mck --discovery-token-ca-cert-hash
最后结果为：
image.png
7.13、高可用测试
在任意一个master上创建一个nginx-deployment.yaml文件，并创建这个Deployment
#cat nginx-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-ingress-test
spec:
replicas: 2
selector:
matchLabels:
app: nginx-ingress-test
template:
metadata:
labels:
app: nginx-ingress-test
spec:
containers:
- name: nginx
image: nginx
imagePullPolicy: IfNotPresent
ports:
- containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: nginx-svc
spec:
type: NodePort
ports:
- name: http
port: 80
targetPort: 80
protocol: TCP
nodePort: 80
selector:
app: nginx-ingress-test
# kubectl apply -f nginx-deployment.yaml
image.png
下面可以看到VIP在master02上（因为我们在配置keepalive时给它配置的优先级最高）
image.png
执行重启master02后：
VIP漂移到了master03上
重启成功后：
VIP又漂移回master02上
