kubernetes集群——高可用(haproxy+keeplived分布式)搭建应用
一k8s高可用集群二实验环境server1172.25.10.1harbor仓库server2172.25.10.2haproxyserver3172.25.10.3haproxyserver4172.25.10.4masterserver5172.25.10.5masterserver6 172.25.10.6masterserver7 172.25.10.7worke node三配置调度器ha
一、k8s高可用集群原理图
二、实验环境
server1 172.25.10.1 harbor仓库
server2 172.25.10.2 haproxy+keepalived
server3 172.25.10.3 haproxy+keepalived
server4 172.25.10.4 master:server
server5 172.25.10.5 master
server6 172.25.10.6 master
server7 172.25.10.7 worke node
三、配置调度器haproxy
在server2/3上
yum install haproxy keepalived -y
haproxy配置:
cd /etc/haproxy/
vim haproxy.cfg
注意当haproxy和与k8s集群master节点在同一台主机上不能使用6443端口
当前我们是分开的,所以不影响
listen admin_status 方便在浏览器监控,可以不指定
bind *:80 监控80端口
mode http
stats uri /status 访问地址:/status
frontend main *:6443 指定端口
mode tcp
default_backend apiserver
backend apiserver
balance roundrobin
mode tcp
server4 app1 172.25.10.4:6443 check 后端多个master节点
server5 app2 172.25.10.5:6443 check
server6 app3 172.25.10.6:6443 check
systemctl enable --now haproxy.service 开机启动
[root@server2 haproxy]# netstat -atnpl | grep 6443 查看端口
tcp 0 0 0.0.0.0:6443 0.0.0.0:* LISTEN 24278/haproxy
vim haproxy.cfg 内容如下
四、配置高可用keepalived
[root@server2 keepalived]# vim keepalived.cfg
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost 邮箱
}
notification_email_from keepalived@localhost 服务邮箱
smtp_server 127.0.0.1 本机回环网路地址
smtp_connect_timeout 30
router_id LVS_DEVEL
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_instance VI_1 {
state MASTER 备机server3为BACKUP
interface eth0
virtual_router_id 51
priority 100 备机server3为优先级为50
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
check_haproxy
}
virtual_ipaddress {
172.25.10.100 vip
}
}
virtual_server 172.25.10.100 443 {
delay_loop 6 健康检测时间间隔
lb_algo rr 轮询
lb_kind DR DR模式
#persistence_timeout 50 注释持续连接;当前是均衡调度
protocol TCP 使用tcp模式
real_server 172.25.10.4 6443 {
weight 1
TCP_CHECK {
connect_timeout 3 后端的master主机数量
retry 3 失败之后重试次数
delay_beforce_retry 3 重试间隔时间
}
}
real_server 172.25.10.5 6443 {
weight 1
TCP_CHECK {
connect_timeout 3
retry 3
delay_beforce_retry
}
}
real_server 172.25.10.6 6443 {
weight 1
TCP_CHECK {
connect_timeout 3
retry 3
delay_beforce_retry
}
}
}
server2/3:systemctl enable --now keepalived.service
查看日志无报错
vip已经出现在server2上
五、接下来配置k8s集群
5.1所有节点server4/5/6/7进行以下操作(安装docker)
yum install docker-ce -y
[root@server4 ~]# cd /etc/docker/
[root@server4 docker]# ls
daemon.json reg.westos.org #(harbor)仓库认证证书
[root@server4 docker]# cat daemon.json
{
"registry-mirrors": ["https://reg.westos.org"], 仓库指向
"exec-opts": ["native.cgroupdriver=systemd"],
"log-driver": "json-file",
"log-opts": {
"max-size": "100m"
},
"storage-driver": "overlay2",
"storage-opts": [
"overlay2.override_kernel_check=true"
]
}
[root@server4 ~]# systemctl enable --now docker
swapoff -a 关闭swap分区
[root@server4 docker]# vim /etc/fstab
[root@server4 docker]# cat /etc/fstab 禁用swap
#/dev/mapper/rhel-swap swap swap defaults 0 0
[root@server4 ~]# cat /etc/hosts
172.25.10.1 server1 reg.westos.org
[root@server4 ~]# cat /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
[root@server4 ~]# sysctl --system
[root@server4 ~]# systemctl restart docker
5.2安装k8s
server4/5/6/7: yum install -y ipvsadm
加载内核模块:(kube_proxy使用IPVS模式)
ip_vs_rr
ip_vs_wrr
ip_vs_sh
nf_conntrack_ipv4
所有集群配置yum源
[root@server4 yum.repos.d]# cat k8s.repo
[Kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
gpgcheck=0
指定版本号与仓库中的相同
yum install -y kubeadm-1.18.3-0 kubelete-1.18.3-0 kubectl-1.18.3-0
在server4生成kubeadm-init.yaml文件
kubeadm config print init-defaults > kubeadm-init.yaml
vim kubeadm-init.yaml 编辑
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
- system:bootstrappers:kubeadm:default-node-token
token: abcdef.0123456789abcdef
ttl: 24h0m0s
usages:
- signing
- authentication
kind: InitConfiguration
localAPIEndpoint:
advertiseAddress: 172.25.10.4 #指定当前主机ip
bindPort: 6443 端口
nodeRegistration:
criSocket: /var/run/dockershim.sock
name: server4 主机名称
taints:
- effect: NoSchedule
key: node-role.kubernetes.io/master
---
apiServer:
timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: "172.25.10.100:6443" 指定集群高可用的vip及端口
controllerManager: {}
dns:
type: CoreDNS
etcd:
local:
dataDir: /var/lib/etcd
imageRepository: reg.westos.org/library 指定仓库位置
kind: ClusterConfiguration
kubernetesVersion: v1.18.3 注意版本
networking:
dnsDomain: cluster.local
podSubnet: 10.244.0.0/16 指定pod网段
serviceSubnet: 10.96.0.0/12 指定服务网段
scheduler: {}
--- 指定使用的模式为ipvs,若不指定默认使用的是iptables,也可以每个主机加载ipvs内核模块
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs
列出镜像
本地harbor仓库预先拉取镜像
master节点添加vip
yum install -y arptables_jf 所有master 节点安装
先给server4添加vip,其他主机需要在成为备选master主机之后并且能在高可用节点上看到后端的主机然后在添加vip
[root@server4 ~]# ip addr add 172.25.10.100/24 dev eth0 临时添加
[root@server4 ~]# arptables -A INPUT -d 172.25.10.100 -j DROP 拒绝所有访问172.25.10.100的IP主机来源
[root@server4 ~]# arptables -A OUPUT -s 172.25.10.100 -j mangle --mangle-ip-s 172.25.10.4 172.25.10.100——>172.25.10.4
[root@server4 ~]# arptables-save > /etc/sysconfig/arptables 保存策略信息
[root@server4 ~]# cat /etc/sysconfig/arptables 查看
*filter
:INPUT ACCEPT
:OUTPUT ACCEPT
:FORWARD ACCEPT
-A INPUT -j DROP -d 172.25.10.100
-A INPUT -j mangle -s 172.25.10.100 --mangle-ip-s 172.25.10.4
初始化
--upload-certs:同步多个master节点证书
[root@server4 ~]# kubeadm init --config kubeadm-init.yaml --upload-certs
第一个join是添加master
第一个join是添加worker
server4成为master
[root@server4 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
server4 Ready master 5m43s v1.18.5
在高可用主机上查看
可以看到后端的master主机
每次初始化都要重新拷贝文件
cp /etc/kubernetes/admin.conf ~/.kube/config
添加server5/6:master
server5/6以经添加成功
添加vip
server5/6相同的操作
[root@server5 ~]# ip addr add 172.25.10.100/24 dev eth0
[root@server5 ~]# arptables -A INPUT -d 172.25.10.100 -j DROP
[root@server5 ~]# arptables -A OUTPUT -s 172.25.10.100 -j mangle --mangle-ip-s 172.25.10.5
[root@server5 ~]# arptables-save > /etc/sysconfig/arptables
[root@server5 ~]# cat /etc/sysconfig/arptables
*filter
:INPUT ACCEPT
:OUTPUT ACCEPT
:FORWARD ACCEPT
-A INPUT -j DROP -d 172.25.10.100
-A OUTPUT -j mangle -s 172.25.10.100 --mangle-ip-s 172.25.10.5
在server4查看所有master的信息
[root@server4 ~]# kubectl -n kube-system describe cm kubeadm-config
添加server7为worker
运行网络插件
vim kube-flannel.yml
image: flannel:v0.12.0-amd64 仓库中必须有此镜像
运行一个pod接下来进行高可用集群的测试
查看vip的主机
[root@server2 ~]# systemctl stop keepalived.service 停止服务
查看到VIP已经漂移到server3
[root@server4 ~]# poweroff 关闭当前master节点
在server3上查看server4已经被移出高可用集群
查看pod依然运行
注意此时集群不能在有任何一台master主机宕掉,否则会变成单点集群;最低必须有三台master才可以高可用
启动server2的keepalived服务VIP已经被夺回,server2的优先级高于server3
启动server4需要重新添加VIP和启动服务。
[root@server4 ~]# ip addr add 172.25.10.100/24 dev eth0
[root@server4 ~]# systemctl start arptables.service
[root@server4 ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
demo 1/1 Running 1 14m
[root@server4 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
server4 Ready master 41m v1.18.5
server5 Ready master 33m v1.18.5
server6 Ready master 23m v1.18.5
server7 Ready <none> 17m v1.18.5
补充
当haproxy+keepalived与k8s的master节点存在于一台主机上特别注意端口不能同时使用6443
以下是配置文件内的不同之处,具体的k8s部署和docker安装与上面的分布式相同
在同一主机上不需要再设置arptables防火墙策略
vim /etc/keepalived/keepalived.cfg
global_defs {
notification_email {
root@localhost
}
notification_email_from keepalived@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script check_haproxy {
script "/etc/keepalived/check_haproxy.sh"
interval 5
}
vrrp_instance VI_1 {
state MASTER //备机设置为BACKUP
interface eth0
virtual_router_id 51
priority 100 //备机设置低优先级50
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script { 指定脚本
check_haproxy
}
virtual_ipaddress {
172.25.0.100
}
}
}
编辑脚本
cd /etc/keepalived/
vim check_haproxy.sh
#!/bin/bash
systemctl status haproxy &> /dev/null
if [ $? != 0 ];then
systemctl stop keepalived
fi
cat /etc/haproxy/haproxy.cfg
#---------------------------------------------------------------------
# Example configuration for a possible web application. See the
# full configuration options online.
#
# http://haproxy.1wt.eu/download/1.4/doc/configuration.txt
#
#---------------------------------------------------------------------
#---------------------------------------------------------------------
# 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 127.0.0.1 local2
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 4000
user haproxy
group haproxy
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
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
#---------------------------------------------------------------------
# main frontend which proxys to the backends
#---------------------------------------------------------------------
frontend main *:8443 在同一个主机上6443端口已经被master占用
mode tcp
default_backend apiserver
#---------------------------------------------------------------------
# round robin balancing between the various backends
#---------------------------------------------------------------------
backend app
mode tcp
balance roundrobin
server app1 172.25.10.2:8443 check
server app2 172.25.10.3:8443 check
server app3 172.25.10.4:8443 check
vim kubeadm-init.yaml 编辑
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
- system:bootstrappers:kubeadm:default-node-token
token: abcdef.0123456789abcdef
ttl: 24h0m0s
usages:
- signing
- authentication
kind: InitConfiguration
localAPIEndpoint:
advertiseAddress: 172.25.10.4 #指定当前主机ip
bindPort: 6443 端口
nodeRegistration:
criSocket: /var/run/dockershim.sock
name: server4 主机名称
taints:
- effect: NoSchedule
key: node-role.kubernetes.io/master
---
apiServer:
timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: "172.25.10.100:8443 指定集群高可用的vip及端口
controllerManager: {}
dns:
type: CoreDNS
etcd:
local:
dataDir: /var/lib/etcd
imageRepository: reg.westos.org/library 指定仓库位置
kind: ClusterConfiguration
kubernetesVersion: v1.18.3 注意版本
networking:
dnsDomain: cluster.local
podSubnet: 10.244.0.0/16 指定pod网段
serviceSubnet: 10.96.0.0/12 指定服务网段
scheduler: {}
--- 指定使用的模式为ipvs,若不指定默认使用的是iptables,也可以每个主机加载ipvs内核模块
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs
更多推荐
所有评论(0)