上一篇文章我们已经将k8s集群部署成功,但是我们只是部署了单节master点的k8s,接下来我们要部署master的高可用节点,此时我们用到了lb节点,那么lb节点需要部署多节点避免单点故障
架构
环境
系统 角色 IP
centos7.4 master-1 10.10.25.149
centos7.4 master-2 10.10.25.112
centos7.4 node-1 10.10.25.150
centos7.4 node-2 10.10.25.151
centos7.4 lb-1 backup 10.10.25.111
centos7.4 lb-2 master 10.10.25.110
centos7.4 VIP 10.10.25.113部署master02 节点
拷贝master01上面的 /opt/kubernetes/目录
scp -r /opt/kubernetes/ [email protected]:/opt
拷贝master01上的相关服务
scp /usr/lib/systemd/system/{kube-apiserver,kube-scheduler,kube-controller-manager}.service [email protected]:/usr/lib/systemd/system
vim /usr/lib/systemd/system/kube-apiserver.service
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
[Service]
ExecStart=/opt/kubernetes/bin/kube-apiserver \
--admission-control=NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota,NodeRestriction \
--bind-address=10.10.25.112 \
--insecure-bind-address=127.0.0.1 \
--authorization-mode=Node,RBAC \
--runtime-config=rbac.authorization.k8s.io/v1 \
--kubelet-https=true \
--anonymous-auth=false \
--basic-auth-file=/opt/kubernetes/ssl/basic-auth.csv \
--enable-bootstrap-token-auth \
--token-auth-file=/opt/kubernetes/ssl/bootstrap-token.csv \
--service-cluster-ip-range=10.1.0.0/16 \
--service-node-port-range=20000-40000 \
--tls-cert-file=/opt/kubernetes/ssl/kubernetes.pem \
--tls-private-key-file=/opt/kubernetes/ssl/kubernetes-key.pem \
--client-ca-file=/opt/kubernetes/ssl/ca.pem \
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \
--etcd-cafile=/opt/kubernetes/ssl/ca.pem \
--etcd-certfile=/opt/kubernetes/ssl/kubernetes.pem \
--etcd-keyfile=/opt/kubernetes/ssl/kubernetes-key.pem \
--etcd-servers=https://10.10.25.149:2379,https://10.10.25.150:2379,https://10.10.25.151:2379 \
--enable-swagger-ui=true \
--allow-privileged=true \
--audit-log-maxage=30 \
--audit-log-maxbackup=3 \
--audit-log-maxsize=100 \
--audit-log-path=/opt/kubernetes/log/api-audit.log \
--event-ttl=1h \
--v=2 \
--logtostderr=false \
--log-dir=/opt/kubernetes/log
Restart=on-failure
RestartSec=5
Type=notify
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
启动apiserver
systemctl start kube-apiserver
# ps -aux | grep kube
systemctl start kube-scheduler kube-controller-manager
加入系统path
vim /root/.bash_profile
添加
PATH=$PATH:$HOME/bin:/opt/kubernetes/bin
source .bash_profile
查看组件状态
# /opt/kubernetes/bin/kubectl get cs
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-1 Healthy {"health":"true"}
etcd-2 Healthy {"health":"true"}
etcd-0 Healthy {"health":"true"}
此时已经说明可以连接到ETCD集群查看node状态
# /opt/kubernetes/bin/kubectl get node
NAME STATUS ROLES AGE VERSION
10.10.25.150 NotReady <none> 14d v1.10.3
10.10.25.151 NotReady <none> 14d v1.10.3
说明master02 还无法与node通信配置单节点LB负载均衡
注:做高可用集群时间上需要同步
lb02节点配置
配置nginx yum源,使用4层代理做
vim /etc/yum.repos.d/nginx.repo
[nginx]
name=nginx repo
baseurl=https://nginx.org/packages/centos/7/$basearch/
gpgcheck=0
enabled=1
yum install -y nginx修改Nginx配置文件
vim /etc/nginx/nginx.conf
stream {
log_format main "remote_addr $upstream_addr $time_local $status";
access_log /var/log/nginx/k8s-access.log main;
upstream k8s-apiserver {
server 10.10.25.149:6443;
server 10.10.25.112:6443;
}
server {
listen 10.10.25.110:6443;
proxy_pass k8s-apiserver;
}
}
修改node节点
cd /opt/kubernetes/cfg/
vim bootstrap.kubeconfig
修改 server: https://10.10.25.149:6443 为
server: https://10.10.25.110:6443
vim kubelet.kubeconfig
修改 server: https://10.10.25.149:6443 为
server: https://10.10.25.110:6443
vim kube-proxy.kubeconfig
修改 server: https://10.10.25.149:6443 为
server: https://10.10.25.110:6443
systemctl restart kubelet
systemctl restart kube-proxy
此时启动以后会发现master01 master02 都无法与node节点通讯,查看node日志发现,提示证书错误,大致意思是kube-proxy证书是master01节点的而不是LB节点的.所以接下来我们需要重新生成Kube-proxy证书
master01重新生成api-server证书
编辑证书json文件
[root@master ssl]# cat kubernetes-csr.json
{
"CN": "kubernetes",
"hosts": [
"127.0.0.1",
"10.10.25.149",
"10.10.25.112",
"10.10.25.110",
"10.10.25.111",
"10.10.25.113",
"10.1.0.1",
"kubernetes",
"kubernetes.default",
"kubernetes.default.svc",
"kubernetes.default.svc.cluster",
"kubernetes.default.svc.cluster.local"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "System"
}
]
}
说明:json文件中的IP包括master01 master02节点IP,所有LB节点IP和VIP 的地址,因为我们最终需要实现 Nginx + Keepalive 0单节点的负载均衡架构
生成证书
cfssl gencert -ca=/opt/kubernetes/ssl/ca.pem \
-ca-key=/opt/kubernetes/ssl/ca-key.pem \
-config=/opt/kubernetes/ssl/ca-config.json \
-profile=kubernetes kubernetes-csr.json | cfssljson -bare kubernetes
拷贝到相应节点
cp kubernetes*.pem /opt/kubernetes/ssl/
scp kubernetes*.pem 10.10.25.112:/opt/kubernetes/ssl/
scp kubernetes*.pem 10.10.25.150:/opt/kubernetes/ssl/
scp kubernetes*.pem 10.10.25.151:/opt/kubernetes/ssl/重启master节点的服务
systemctl start kube-scheduler kube-controller-manager kube-apiserver
重启node节点服务
systemctl restart kube-proxy kubelet验证
# kubectl get node
NAME STATUS ROLES AGE VERSION
10.10.25.150 Ready <none> 15d v1.10.3
10.10.25.151 Ready <none> 15d v1.10.3
说明已经实现了单节点负载均衡.
这里有个地方需要注意,在以上配置都完成并且没有错误的情况下,有可能出现获取到的node状态是notready,有可能出现此问题的有原因是在日志里面发现node无法注册,此时我们需要手动注册,在master01上执行一下命令即可
kubectl get csr|grep 'Pending' | awk 'NR>0{print $1}'| xargs kubectl certificate approve
lb01节点配置
同样安装nginx,过程不赘述，nginx配置也相同。需要改变的只是绑定的IP
vim /etc/nginx/nginx.conf
stream {
log_format main "remote_addr $upstream_addr $time_local $status";
access_log /var/log/nginx/k8s-access.log main;
upstream k8s-apiserver {
server 10.10.25.149:6443;
server 10.10.25.112:6443;
}
server {
listen 10.10.25.111:6443;
proxy_pass k8s-apiserver;
}
}
使用Keepalive实现LB节点的高可用
安装keepalive两个节点都需要
yum install keepalived -y
设置lb02为keepalived为master节点
修改lb02keepalived配置文件
vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 192.168.200.1
smtp_connect_timeout 30
router_id LVS_DEVEL
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_script check_nginx {
script "/etc/keepalived/check_nginx.sh" #脚本检查ngixn状态
}
vrrp_instance VI_1 {
state MASTER
interface ens192
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.10.25.113/24
}
track_script {
check_nginx
}
}
编写nginx状态检测脚本
cat /etc/keepalived/check_nginx.sh
#!/bin/sh
count=$(ps -ef | grep nginx | egrep -cv "grep|$$")
#获取nginx进程数
if [ "$count" -eq 0 ];then
systemctl stop keepalived
fi
授予脚本执行权限
chmod +x /etc/keepalived/check_nginx.sh
启动keepalived
systemctl start keepalived查看是VIP是否生效
ip addr
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 00:0c:29:2e:86:82 brd ff:ff:ff:ff:ff:ff
inet 10.10.25.110/24 brd 10.10.25.255 scope global dynamic ens192
valid_lft 71256sec preferred_lft 71256sec
inet 10.10.25.113/32 scope global ens192
valid_lft forever preferred_lft forever
inet6 fe80::58b8:49be:54a7:4c43/64 scope link
valid_lft forever preferred_lft forever
配置lb01keepalived
修改为backup的keepalived配置文件
cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
[email protected]
[email protected]
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_script check_nginx {
script "/etc/keepalived/check_nginx.sh"
}
vrrp_instance VI_1 {
state BACKUP
interface ens192
virtual_router_id 51
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.10.25.113
}
track_script {
check_nginx
}
}
编写nginx状态检测脚本
cat /etc/keepalived/check_nginx.sh
#!/bin/sh
count=$(ps -ef | grep nginx | egrep -cv "grep|$$")
#获取nginx进程数
if [ "$count" -eq 0 ];then
systemctl stop keepalived
fi
授予脚本执行权限
chmod +x /etc/keepalived/check_nginx.sh
启动lb01keepalived
systemctl start keepalived
Keepalive故障切换
做keepalived故障切换，测试方法
1 打开一个窗口一直ping VIP
2 kill master节点nginx
3 观察VIP是否迁移到备份和VIP的丢包情况
4 启动master节点的nginx 和keepalive
5 观察VIP时候漂移回到master节点 接入K8s集群
将node节点的接入VIP
cd /opt/kubernetes/cfg/
vim bootstrap.kubeconfig
修改 server: https://10.10.25.110:6443 为
server: https://10.10.25.113:6443
vim kubelet.kubeconfig
修改 server: https://10.10.25.110:6443 为
server: https://10.10.25.113:6443
vim kube-proxy.kubeconfig
修改 server: https://10.10.25.110:6443 为
server: https://10.10.25.113:6443
systemctl restart kubelet
systemctl restart kube-proxy
重启服务
systemctl restart kubelet
systemctl restart kube-proxy修改nginx配置文件（两个节点都需要）
cat /etc/nginx/nginx.conf
user nginx;
worker_processes 2;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
}
stream {
log_format main "remote_addr $upstream_addr $time_local $status";
access_log /var/log/nginx/k8s-access.log main;
upstream k8s-apiserver {
server 10.10.25.149:6443;
server 10.10.25.112:6443;
}
server {
listen 0.0.0.0:6443;
proxy_pass k8s-apiserver;
}
}
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
#tcp_nopush on;
keepalive_timeout 65;
#gzip on;
include /etc/nginx/conf.d/*.conf;
}
重启Nginx
systemctl restart nginx验证VIP接入
kubectl get node
NAME STATUS ROLES AGE VERSION
10.10.25.150 Ready <none> 15d v1.10.3
10.10.25.151 Ready <none> 15d v1.10.3
此时说明接入VIP成功