Kubernetes集群生產(chǎn)環(huán)境搭建全過程

William_Sang 發(fā)布于2019-07-01 17:26 / 3331人閱讀

摘要：本文詳細(xì)講解如何搭建高可用的集群，以下簡稱由三臺服務(wù)器組成集群命名為，，，用來代替集群搭建首先搭建集群為集群的核心組成部分，負(fù)責(zé)所有集群配置信息和服務(wù)信息的存儲，所以必須要保證高可用，此處采用的靜態(tài)服務(wù)發(fā)現(xiàn)，即在啟動的時候，確定的。

本文詳細(xì)講解如何搭建高可用的Kubernetes集群，以下簡稱k8s

由三臺服務(wù)器(CentOS 7.0)組成master集群,命名為m1，m2，m3，ip用m1 m2 m3來代替

etcd集群搭建

首先搭建etcd集群,etcd為k8s集群的核心組成部分，負(fù)責(zé)所有集群配置信息和服務(wù)信息的存儲，所以必須要保證高可用，此處采用etcd的靜態(tài)服務(wù)發(fā)現(xiàn)，即在etcd啟動的時候，確定etcd node的ip。

yum安裝etcd yum install -y etcd

分別在三臺機(jī)器啟動etcd進(jìn)程(實際操作中需要將m1 m2 m3替換成實際的ip地址)
m1:

etcd -name infra1 -initial-advertise-peer-urls http://m1:2380 -listen-peer-urls http://m1:2380 -listen-client-urls http://m1:2379,http://127.0.0.1:2379 -advertise-client-urls http://m1:2379 -initial-cluster-token etcd-cluster-1 -initial-cluster infra1=http://m1:2380,infra2=http://m2:2380,infra3=http://m3:2380 -initial-cluster-state new

m2:

etcd -name infra2 -initial-advertise-peer-urls http://m2:2380 -listen-peer-urls http://m2:2380 -listen-client-urls http://m2:2379,http://127.0.0.1:2379 -advertise-client-urls http://m2:2379 -initial-cluster-token etcd-cluster-1 -initial-cluster infra1=http://m1:2380,infra2=http://m2:2380,infra3=http://m3:2380 -initial-cluster-state new

m3:

etcd -name infra3 -initial-advertise-peer-urls http://m3:2380 -listen-peer-urls http://m3:2380 -listen-client-urls http://m3:2379,http://127.0.0.1:2379 -advertise-client-urls http://m3:2379 -initial-cluster-token etcd-cluster-1 -initial-cluster infra1=http://m1:2380,infra2=http://m2:2380,infra3=http://m3:2380 -initial-cluster-state new

集群啟動后，選取一臺機(jī)器執(zhí)行 etcdctl cluster-health

如果出現(xiàn)3個類似 member cbfa6350b369c3a is healthy 的字樣，說明etcd集群部署成功。

實戰(zhàn)中采取了systemd來進(jìn)行管理
新建文件 /usr/lib/systemd/system/etcd.service
內(nèi)容如下：

[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
WorkingDirectory=/root
ExecStart=etcd -name infra1 -initial-advertise-peer-urls http://m1:2380 -listen-peer-urls http://m1:2380 -listen-client-urls http://m1:2379,http://127.0.0.1:2379 -advertise-client-urls http://m1:2379 -initial-cluster-token etcd-cluster-1 -initial-cluster infra1=http://m1:2380,infra2=http://m2:2380,infra3=http://m3:2380 -initial-cluster-state new
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

這樣可以使用 systemctl start etcd來啟動服務(wù)

Kubernete master搭建

master搭建是通過自動化搭建腳本實現(xiàn)的腳本內(nèi)容如下

#!/bin/bash
echo "################ Prerequisites..."
systemctl stop firewalld
systemctl disable firewalld
yum -y install ntp
systemctl start ntpd
systemctl enable ntpd

echo "################ Installing flannel..."
#安裝flannel
yum install flannel -y

echo "################ Add subnets for flannel..."
A_SUBNET=172.17.0.0/16
B_SUBNET=192.168.0.0/16
C_SUBNET=10.254.0.0/16

FLANNEL_SUBNET=$A_SUBNET
SERVICE_SUBNET=$B_SUBNET
OCCUPIED_IPs=(`ifconfig -a | grep "inet " | cut -d ":" -f 2 |cut -d " " -f 1 | grep -v "^127"`)
for ip in ${OCCUPIED_IPs[@]};do
    if [ $(ipcalc -n $ip/${A_SUBNET#*/}) == $(ipcalc -n ${A_SUBNET}) ];then
        FLANNEL_SUBNET=$C_SUBNET
        SERVICE_SUBNET=$B_SUBNET
        break
    fi
    if [ $(ipcalc -n $ip/${B_SUBNET#*/}) == $(ipcalc -n ${B_SUBNET}) ];then
        FLANNEL_SUBNET=$A_SUBNET
        SERVICE_SUBNET=$C_SUBNET
        break
    fi
    if [ $(ipcalc -n $ip/${C_SUBNET#*/}) == $(ipcalc -n ${C_SUBNET}) ];then
        FLANNEL_SUBNET=$A_SUBNET
        SERVICE_SUBNET=$B_SUBNET
        break
    fi
done

while ((1));do
    sleep 2
    etcdctl cluster-health
    flag=$?
    if [ $flag == 0 ];then
etcdctl mk /coreos.com/network/config "{"Network":""${FLANNEL_SUBNET}""}"
        break
    fi
done

echo "################ Starting flannel..."
#此處將m1 m2 m3 換成實際的ip
echo -e "FLANNEL_ETCD="http://m1:2379,http://m2:2379,http://m3:2379"
FLANNEL_ETCD_KEY="/coreos.com/network"" > /etc/sysconfig/flanneld
systemctl enable flanneld
systemctl start flanneld

echo "################ Installing K8S..."
yum -y install kubernetes
echo "KUBE_API_ADDRESS="--address=0.0.0.0"
KUBE_API_PORT="--port=8080"
KUBELET_PORT="--kubelet_port=10250"
KUBE_ETCD_SERVERS="--etcd_servers=http://m1:2379,http://m2:2379,http://m3:2379"
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range="${SERVICE_SUBNET}""
KUBE_ADMISSION_CONTROL="--admission_control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"
KUBE_API_ARGS=""" > /etc/kubernetes/apiserver

echo "################ Start K8S components..."
for SERVICES in kube-apiserver kube-controller-manager kube-scheduler; do
    systemctl restart $SERVICES
    systemctl enable $SERVICES
    systemctl status $SERVICES
done

Kubernete node搭建

node的搭建也是通過自動化部署腳本實現(xiàn)的，腳本內(nèi)容如下：

#!/bin/bash

echo "################ Prerequisites..."
#關(guān)閉firewall 開啟ntp時間同步
systemctl stop firewalld
systemctl disable firewalld
yum -y install ntp
systemctl start ntpd
systemctl enable ntpd

#安裝kubernetes所需要的幾個軟件
yum -y install kubernetes docker flannel bridge-utils


#此處使用了一個vip 命名為vip 實際部署時需要替換為你的集群的vip 使用此ip的服務(wù)有 kube-master（8080） registry（5000） skydns（53）

echo "################ Configuring nodes..."
echo "################ Configuring nodes > Find Kube master..."
KUBE_REGISTRY_IP="vip"
KUBE_MASTER_IP="vip"
echo "################ Configuring nodes > Configuring Minion..."
echo -e "KUBE_LOGTOSTDERR="--logtostderr=true"
KUBE_LOG_LEVEL="--v=0"
KUBE_ALLOW_PRIV="--allow_privileged=false"
KUBE_MASTER="--master=http://${KUBE_MASTER_IP}:8080"" > /etc/kubernetes/config
echo "################ Configuring nodes > Configuring kubelet..."
#取每個node機(jī)器的eth0的ip作為標(biāo)識
KUBE_NODE_IP=`ifconfig eth0 | grep "inet " | awk "{print $2}"`

#api_servers 使用master1 master2 master3的ip數(shù)組形式
echo -e "KUBELET_ADDRESS="--address=0.0.0.0"
KUBELET_PORT="--port=10250"
KUBELET_HOSTNAME="--hostname_override=${KUBE_NODE_IP}"
KUBELET_API_SERVER="--api_servers=http://m1:8080,http://m2:8080,http://m3:8080"
KUBELET_ARGS="--cluster-dns=vip --cluster-domain=k8s --pod-infra-container-image=${KUBE_REGISTRY_IP}:5000/pause:latest"" > /etc/kubernetes/kubelet


#flannel讀取etcd配置信息 為本機(jī)的docker0分配ip 保證node集群子網(wǎng)互通
echo "################ Configuring flannel..."
echo -e "FLANNEL_ETCD="http://m1:2379,http://m2:2379,http://m3:2379"
FLANNEL_ETCD_KEY="/coreos.com/network"" > /etc/sysconfig/flanneld


echo "################ Accept private registry..."
echo "OPTIONS="--selinux-enabled --insecure-registry ${KUBE_REGISTRY_IP}:5000"
DOCKER_CERT_PATH=/etc/docker" > /etc/sysconfig/docker

echo "################ Start K8S Components..."
systemctl daemon-reload
for SERVICES in kube-proxy flanneld; do
    systemctl restart $SERVICES
    systemctl enable $SERVICES
    systemctl status $SERVICES
done

echo "################ Resolve interface conflicts..."
systemctl stop docker
ifconfig docker0 down
brctl delbr docker0

echo "################ Accept private registry..."
echo -e "OPTIONS="--selinux-enabled --insecure-registry ${KUBE_REGISTRY_IP}:5000"
DOCKER_CERT_PATH=/etc/docker" > /etc/sysconfig/docker

for SERVICES in docker kubelet; do
    systemctl restart $SERVICES
    systemctl enable $SERVICES
    systemctl status $SERVICES
done

至此，Kubernetes master和node的搭建就結(jié)束了。