K8s集群部署之高可用

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weixin_33724570

767人浏览 · 2019-03-23 15:05:00

weixin_33724570 · 2019-03-23 15:05:00 发布

2019独角兽企业重金招聘Python工程师标准>>>

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/ root@10.10.25.112:/opt
拷贝master01上的相关服务
scp /usr/lib/systemd/system/{kube-apiserver,kube-scheduler,kube-controller-manager}.service root@10.10.25.112:/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 {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   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 {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   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

转载于:https://my.oschina.net/54188zz/blog/3026691

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