K8S 实战（一）| 运营管理生产级 K8S 高可用集群之初始化

平台环境

软件信息

• CentOS Linux release 7.7.1908 (Kernel 3.10.0-1062.18.1.el7.x86_64)
• Docker CE 18.09.9
• Kubernetes v1.18.2
• Calico v3.8
• Keepalived v1.3.5
• HAproxy v1.5.18

硬件信息

主机名

ip

master01

192.168.10.12

master02

192.168.10.13

master03

192.168.10.14

work01

192.168.10.15

work02

192.168.10.16

work03

192.168.10.17

VIP

192.168.10.19

集群装备

初始化

master/worker 均履行

# cat >> /etc/hosts << EOF
192.168.10.12    master01
192.168.10.13    master02
192.168.10.14    master03
192.168.10.15    work01
192.168.10.16    work02
192.168.10.17    work03
EOF
# 封闭防火墙
systemctl stop firewalld
systemctl disable firewalld
# 封闭 SeLinux
setenforce 0
sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
# 封闭 swap
swapoff -a
yes | cp /etc/fstab /etc/fstab_bak
cat /etc/fstab_bak |grep -v swap > /etc/fstab
# 装置wget
yum install wget -y
# 备份
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
# 阿里云yum源
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo# 获取阿里云epel源
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo# 清理缓存并创立新的缓存
yum clean all && yum makecache
# 更新
yum update -y
#同步时刻
timedatectl
timedatectl set-ntp true

装置 Docker

master/worker 均装置

# 装置 Docker CE
# 设置仓库
# 装置所需包
yum install -y yum-utils device-mapper-persistent-data lvm2
# 新增 Docker 装置源
yum-config-manager \
    --add-repo \
    http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
# 装置 Docker CE.
yum install -y containerd.io \
    docker-ce-18.09.9 \
    docker-ce-cli-18.09.9
# 发动 Docker 并增加开机发动
systemctl start docker
systemctl enable docker
#将Docker 的 Cgroup Driver 修改为 systemd
#修改为国内源
cat > /etc/docker/daemon.json <<EOF
{
    "exec-opts": ["native.cgroupdriver=systemd"],
    "log-driver": "json-file",
    "log-opts": {
    "max-size": "100m"
    },
    "storage-driver": "overlay2",
    "registry-mirrors":[
        "http://hub-mirror.c.163.com",
        "https://docker.mirrors.ustc.edu.cn",
        "https://registry.docker-cn.com"
    ]}
EOF
mkdir -p /etc/systemd/system/docker.service.d
# Restart docker.
systemctl daemon-reload
systemctl restart docker

装置 kubeadm、kubelet 、kubectl

master/worker 节点均履行

# 装备K8S的yum源，最好运用官方源
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg  https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
# 增加装备
cat <<EOF > /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward=1
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
# 加载
sysctl --system
# 装置当时日期最新稳定版(v1.18.2) kubelet、 kubeadm 、kubectl
yum install -y kubelet-1.18.2 kubeadm-1.18.2 kubectl-1.18.2 --disableexcludes=kubernetes
# 发动并设置 kubelet 开机发动
systemctl start kubelet
systemctl enable kubelet

HAProxy 完成 apiserver 负载均衡集群

所有 master 节点履行

yum install haproxy-1.5.18 -y
cat > /etc/haproxy/haproxy.cfg <<EOF
global
    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
defaults
    mode                    http
    log                     global
    option                  httplog
    option                  dontlognull
    option http-server-close
    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
frontend  k8s-api
    mode tcp
    option tcplog
    bind *:16443
    default_backend      k8s-api
backend k8s-api
    mode        tcp
    balance     roundrobin
    server master01 192.168.10.12:6443 check
    server master02 192.168.10.13:6443 check
    server master03 192.168.10.14:6443 check
EOF

所有 master 节点发动 HAProxy

systemctl start haproxy
systemctl enable haproxy

Keepalived完成 apiserver 高可用集群

所有 master 节点履行

yum -y install keepalived psmisc

master01 上 keepalived 的装备：

# cat > /etc/keepalived/keepalived.conf <<EOF
! Configuration File for keepalived
global_defs {
   router_id master01
   script_user root
   enable_script_security 
}
vrrp_script check_haproxy {
    script "killall -0 haproxy"
    interval 2
    weight 10
}
vrrp_instance VI_1 {
    state MASTER 
    interface ens192
    virtual_router_id 50
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.10.19
    }
    track_script {
        check_haproxy
    }
}
EOF

master02 上 keepalived 的装备：

# cat > /etc/keepalived/keepalived.conf <<EOF
! Configuration File for keepalived
global_defs {
   router_id master02
   script_user root
   enable_script_security 
}
vrrp_script check_haproxy {
    script "killall -0 haproxy"
    interval 2
    weight 10
}
vrrp_instance VI_1 {
    state BACKUP 
    interface ens192
    virtual_router_id 50
    priority 98
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.10.19
    }
    track_script {
        check_haproxy
    }
}
EOF

master03 上 keepalived 的装备：

# cat > /etc/keepalived/keepalived.conf <<EOF
! Configuration File for keepalived
global_defs {
   router_id master03
   script_user root
   enable_script_security 
}
vrrp_script check_haproxy {
    script "killall -0 haproxy"
    interval 2
    weight 10
}
vrrp_instance VI_1 {
    state BACKUP 
    interface ens192
    virtual_router_id 50
    priority 96
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.10.19
    }
    track_script {
        check_haproxy
    }
}
EOF

所有 master 节点履行

service keepalived start
systemctl enable keepalived

留意

• vrrp_script 中参数 weight 一定要大于 master 和 backup 的 priority 的相差值
• vrrp_instance 中参数 nopreempt 能够防止 master 恢复后自动回切

创立 K8S 集群

在初始化之前，需要先设置 hosts 解析 MASTER_IP 为 VIP 的地址 APISERVER_NAME 为 VIP 的域名

export MASTER_IP=192.168.10.19
export APISERVER_NAME=k8s.api
echo "${MASTER_IP} ${APISERVER_NAME}" >> /etc/hosts

在 master01 上履行 kubeadm init 进行初始化

kubeadm init \
 --apiserver-advertise-address 0.0.0.0 \
 --apiserver-bind-port 6443 \
 --cert-dir /etc/kubernetes/pki \
 --control-plane-endpoint k8s.api \
 --image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
 --kubernetes-version 1.18.2 \
 --pod-network-cidr 192.10.0.0/16 \
 --service-cidr 192.20.0.0/16 \
 --service-dns-domain cluster.local \
 --upload-certs

加载环境变量

master01 上履行，用于管理集群

如果在root用户下

echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
source .bash_profile

如果非root用户下

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

装置 Pod 网络组件

master01 上履行

# 获取装备文件
mkdir calico && cd calico
wget https://docs.projectcalico.org/v3.8/manifests/calico.yaml
# 修改装备文件
vi calico.yaml
# 找到 192.168.0.0/16 ，修改为 192.10.0.0/16
# 部署 Pod 网络组件
kubectl apply -f calico.yaml

实时检查 pod 的状态

watch kubectl get pods --all-namespaces -o wide

增加其他 master 节点到K8S集群

在其他 master 节点履行

运用 master01 上 kubeadm init 的履行结果中包含 join 的指令信息

端口由 6443 修改为 16443

export MASTER_IP=192.168.10.19
export APISERVER_NAME=k8s.api
echo "${MASTER_IP} ${APISERVER_NAME}" >> /etc/hosts
kubeadm join k8s.api:16443 --token ztjux9.2tau56zck212j9ra \
    --discovery-token-ca-cert-hash sha256:a2b552266902fb5f6620330fc1a6638a9cdd6fec3408edba1082e6c8389ac517 \
    --control-plane --certificate-key 961494e7d0a9de0219e2b0dc8bdaa9ca334ecf093a6c5f648aa34040ad39b61a
echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
source .bash_profile

将所有 Worker 节点增加到K8S集群

在worker 节点履行

运用 master01 上 kubeadm init 的履行结果中包含 join 的指令信息

端口由 6443 修改为 16443

export MASTER_IP=192.168.10.19
export APISERVER_NAME=k8s.api
echo "${MASTER_IP} ${APISERVER_NAME}" >> /etc/hosts
kubeadm join k8s.api:16443 --token ztjux9.2tau56zck212j9ra \
    --discovery-token-ca-cert-hash sha256:a2b552266902fb5f6620330fc1a6638a9cdd6fec3408edba1082e6c8389ac517

master01 上检查集群

watch kubectl get nodes -o wide

全部为 Ready 阐明集群装置成功。

破坏性测试

• 把 master01 的 haproxy 停掉
• 把 master01 机器关机

能够看到 VIP 能够漂移到 master02 上

然后能够在 master02 做相同操作观察 VIP 是否能够漂到 master03 上

结束语

今天主要是实战搭建了 K8S 高可用负载均衡集群，是我实际操作的记录。

那么你有没有发现有个地方其实能够进一步的优化。