环境准备
查看centos版本
cat /etc/redhat-release
CentOS Linux release 7.5.1804 (Core)
网络静态配置
cat /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
IPADDR=192.168.191.10
NETMASK=255.255.255.0
GATEWAY=192.168.191.2
DNS1=8.8.8.8
DNS2=114.114.114.114
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens33
UUID=c8bbd3f8-f1ac-4f11-8f2d-69604f55a80a
DEVICE=ens33
ONBOOT=yes
主机名映射
cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.191.10 k8s-01
192.168.191.11 k8s-02
192.168.191.12 k8s-03
192.168.191.13 k8s-04
修改主机名并且刷新主机名显示
hostnamectl set-hostname k8s-01
bash
设置网络环境
systemctl stop firewalld
systemctl disable firewalld
iptables -F && iptables -X && iptables -F -t nat && iptables -X -t nat
iptables -P FORWARD ACCEPT
swapoff -a
sed -i '/ swap / s/^(.*)$/#1/g' /etc/fstab
setenforce 0
sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config
设置免秘钥
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
yum install -y expect
#分发公钥
ssh-keygen -t rsa -P "" -f /root/.ssh/id_rsa
for i in k8s-01 k8s-02 k8s-03 k8s-04;do
expect -c "
spawn ssh-copy-id -i /root/.ssh/id_rsa.pub root@$i
expect {
"*yes/no*" {send "yes
"; exp_continue}
"*password*" {send "123456
"; exp_continue}
"*Password*" {send "123456
";}
} "
done
更新PATH变量
echo 'PATH=/opt/k8s/bin:$PATH' >>/etc/profile
source /etc/profile
安装依赖包
yum install -y conntrack ntpdate ntp ipvsadm ipset jq iptables curl sysstat libseccomp wget
优化内核参数
cat > kubernetes.conf <<EOF
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
net.ipv4.tcp_tw_recycle=0
vm.swappiness=0 # 禁止使用 swap 空间，只有当系统 OOM 时才允许使用它
vm.overcommit_memory=1 # 不检查物理内存是否够用
vm.panic_on_oom=0 # 开启 OOM
fs.inotify.max_user_instances=8192
fs.inotify.max_user_watches=1048576
fs.file-max=52706963
fs.nr_open=52706963
net.ipv6.conf.all.disable_ipv6=1
net.netfilter.nf_conntrack_max=2310720
EOF
cp kubernetes.conf /etc/sysctl.d/kubernetes.conf
sysctl -p /etc/sysctl.d/kubernetes.conf
时区设置
#将当前的 UTC 时间写入硬件时钟
#重启依赖于系统时间的服务
timedatectl set-timezone Asia/Shanghai
timedatectl set-local-rtc 0
systemctl restart rsyslog
systemctl restart crond
创建相关目录
mkdir -p /opt/k8s/{bin,work} /etc/{kubernetes,etcd}/cert
#在所有节点上执行，因为flanneld是在所有节点运行的
请根据IP进行修改
分发环境变量脚本
source environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp environment.sh root@${node_ip}:/opt/k8s/bin/
ssh root@${node_ip} "chmod +x /opt/k8s/bin/* "
done
安装cfssl工具集
mkdir -p /opt/k8s/cert && cd /opt/k8s
wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
mv cfssl_linux-amd64 /opt/k8s/bin/cfssl
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
mv cfssljson_linux-amd64 /opt/k8s/bin/cfssljson
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
mv cfssl-certinfo_linux-amd64 /opt/k8s/bin/cfssl-certinfo
chmod +x /opt/k8s/bin/*
export PATH=/opt/k8s/bin:$PATH
创建ca配置文件
cd /opt/k8s/work
cat > ca-config.json <<EOF
{
"signing": {
"default": {
"expiry": "87600h"
},
"profiles": {
"kubernetes": {
"usages": [
"signing",
"key encipherment",
"server auth",
"client auth"
],
"expiry": "87600h"
}
}
}
}
EOF
######################
signing 表示该证书可用于签名其它证书，生成的ca.pem证书找中CA=TRUE
server auth 表示client可以用该证书对server提供的证书进行验证
client auth 表示server可以用该证书对client提供的证书进行验证
创建证书签名请求文件
cd /opt/k8s/work
cat > ca-csr.json <<EOF
{
"CN": "kubernetes",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "4Paradigm"
}
],
"ca": {
"expiry": "876000h"
}
}
EOF
生成CA证书和私钥
cd /opt/k8s/work
cfssl gencert -initca ca-csr.json | cfssljson -bare ca
ls ca*
分发证书
#将生成的CA证书、秘钥文件、配置文件拷贝到所有节点的/etc/kubernetes/cert目录下
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /etc/kubernetes/cert"
scp ca*.pem ca-config.json root@${node_ip}:/etc/kubernetes/cert
done
部署kubectl命令行工具
kubectl默认从~/.kube/config读取kube-apiserver地址和认证信息。kube/config只需要部署一次，生成的kubeconfig文件是通用的
下载和解压kubectl
cd /opt/k8s/work
wget http://down.i4t.com/k8s1.14/kubernetes-client-linux-amd64.tar.gz
tar -xzvf kubernetes-client-linux-amd64.tar.gz
分发所有使用kubectl节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp kubernetes/client/bin/kubectl root@${node_ip}:/opt/k8s/bin/
ssh root@${node_ip} "chmod +x /opt/k8s/bin/*"
done
创建admin证书和私钥
kubectl与apiserver https通信，apiserver对提供的证书进行认证和授权。kubectl作为集群的管理工具，需要被授予最高权限，这里创建具有最高权限的admin证书
创建证书签名请求
cd /opt/k8s/work
cat > admin-csr.json <<EOF
{
"CN": "admin",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "system:masters",
"OU": "4Paradigm"
}
]
}
EOF
生成证书和私钥
cd /opt/k8s/work
cfssl gencert -ca=/opt/k8s/work/ca.pem
-ca-key=/opt/k8s/work/ca-key.pem
-config=/opt/k8s/work/ca-config.json
-profile=kubernetes admin-csr.json | cfssljson -bare admin
ls admin*
kubeconfig为kubectl的配置文件，包含访问apiserver的所有信息，如apiserver地址、CA证书和自身使用的证书
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
kubectl config set-cluster kubernetes
--certificate-authority=/opt/k8s/work/ca.pem
--embed-certs=true
--server=${KUBE_APISERVER}
--kubeconfig=kubectl.kubeconfig
kubectl config set-credentials admin
--client-certificate=/opt/k8s/work/admin.pem
--client-key=/opt/k8s/work/admin-key.pem
--embed-certs=true
--kubeconfig=kubectl.kubeconfig
kubectl config set-context kubernetes
--cluster=kubernetes
--user=admin
--kubeconfig=kubectl.kubeconfig
kubectl config use-context kubernetes --kubeconfig=kubectl.kubeconfig
################
--certificate-authority 验证kube-apiserver证书的根证书
--client-certificate、--client-key 刚生成的admin证书和私钥，连接kube-apiserver时使用
--embed-certs=true 将ca.pem和admin.pem证书嵌入到生成的kubectl.kubeconfig文件中 (如果不加入，写入的是证书文件路径，后续拷贝kubeconfig到其它机器时，还需要单独拷贝证书)
分发kubeconfig文件
分发到所有使用kubectl命令的节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p ~/.kube"
scp kubectl.kubeconfig root@${node_ip}:~/.kube/config
done
#保存文件名为~/.kube/config
部署ETCD集群
下载和分发etcd二进制文件
创建etcd集群各节点的x509证书，用于加密客户端(如kubectl)与etcd集群、etcd集群之间的数据流
创建etcd的system unit文件，配置服务参数
检查集群工作状态
etcd集群各节点的名称和IP如下
k8s-01 192.168.191.10
k8s-02 192.168.191.11
k8s-03 192.168.191.12
注意: 没有特殊说明都在k8s-01节点操作
下载和分发etcd二进制文件
cd /opt/k8s/work
wget http://down.i4t.com/k8s1.14/etcd-v3.3.13-linux-amd64.tar.gz
tar -xvf etcd-v3.3.13-linux-amd64.tar.gz
分发二进制文件到集群节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${ETCD_IPS[@]}
do
echo ">>> ${node_ip}"
scp etcd-v3.3.13-linux-amd64/etcd* root@${node_ip}:/opt/k8s/bin
ssh root@${node_ip} "chmod +x /opt/k8s/bin/*"
done
创建etcd证书和私钥
cd /opt/k8s/work
cat > etcd-csr.json <<EOF
{
"CN": "etcd",
"hosts": [
"127.0.0.1",
"192.168.191.10",
"192.168.191.11",
"192.168.191.12"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "4Paradigm"
}
]
}
EOF
生成证书和私钥
cd /opt/k8s/work
cfssl gencert -ca=/opt/k8s/work/ca.pem
-ca-key=/opt/k8s/work/ca-key.pem
-config=/opt/k8s/work/ca-config.json
-profile=kubernetes etcd-csr.json | cfssljson -bare etcd
ls etcd*pem
分发证书和私钥到etcd各个节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${ETCD_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /etc/etcd/cert"
scp etcd*.pem root@${node_ip}:/etc/etcd/cert/
done
创建etcd的启动文件 (这里将配置文件也存放在启动文件里)
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > etcd.service.template <<EOF
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
Documentation=https://github.com/coreos
[Service]
Type=notify
WorkingDirectory=${ETCD_DATA_DIR}
ExecStart=/opt/k8s/bin/etcd \
--data-dir=${ETCD_DATA_DIR} \
--wal-dir=${ETCD_WAL_DIR} \
--name=##NODE_NAME## \
--cert-file=/etc/etcd/cert/etcd.pem \
--key-file=/etc/etcd/cert/etcd-key.pem \
--trusted-ca-file=/etc/kubernetes/cert/ca.pem \
--peer-cert-file=/etc/etcd/cert/etcd.pem \
--peer-key-file=/etc/etcd/cert/etcd-key.pem \
--peer-trusted-ca-file=/etc/kubernetes/cert/ca.pem \
--peer-client-cert-auth \
--client-cert-auth \
--listen-peer-urls=https://##NODE_IP##:2380 \
--initial-advertise-peer-urls=https://##NODE_IP##:2380 \
--listen-client-urls=https://##NODE_IP##:2379,http://127.0.0.1:2379 \
--advertise-client-urls=https://##NODE_IP##:2379 \
--initial-cluster-token=etcd-cluster-0 \
--initial-cluster=${ETCD_NODES} \
--initial-cluster-state=new \
--auto-compaction-mode=periodic \
--auto-compaction-retention=1 \
--max-request-bytes=33554432 \
--quota-backend-bytes=6442450944 \
--heartbeat-interval=250 \
--election-timeout=2000
Restart=on-failure
RestartSec=5
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
为各个节点分发启动文件
#分发会将配置文件中的#替换成ip
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for (( i=0; i < 3; i++ ))
do
sed -e "s/##NODE_NAME##/${MASTER_NAMES[i]}/" -e "s/##NODE_IP##/${ETCD_IPS[i]}/" etcd.service.template > etcd-${ETCD_IPS[i]}.service
done
ls *.service
#NODE_NAMES 和 NODE_IPS 为相同长度的 bash 数组，分别为节点名称和对应的 IP；
分发生成的etcd启动文件到对应的服务器
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp etcd-${node_ip}.service root@${node_ip}:/etc/systemd/system/etcd.service
done
重命名etcd启动文件并启动etcd服务
etcd首次进程启动会等待其他节点加入etcd集群，执行启动命令会卡顿一会，为正常现象
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p ${ETCD_DATA_DIR} ${ETCD_WAL_DIR}"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable etcd && systemctl restart etcd " &
done
#这里我们创建了etcd的工作目录
检查启动结果
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl status etcd|grep Active"
done
如果etcd集群状态不是active (running)，请使用下面命令查看etcd日志
journalctl -fu etcd
验证ETCD集群状态
验证完etcd集群后，在任一etcd节点执行下命令
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ETCDCTL_API=3 /opt/k8s/bin/etcdctl
--endpoints=https://${node_ip}:2379
--cacert=/etc/kubernetes/cert/ca.pem
--cert=/etc/etcd/cert/etcd.pem
--key=/etc/etcd/cert/etcd-key.pem endpoint health
done
我们还可以通过下面命令查看当前etcd集群leader
source /opt/k8s/bin/environment.sh
ETCDCTL_API=3 /opt/k8s/bin/etcdctl
-w table --cacert=/etc/kubernetes/cert/ca.pem
--cert=/etc/etcd/cert/etcd.pem
--key=/etc/etcd/cert/etcd-key.pem
--endpoints=${ETCD_ENDPOINTS} endpoint status
部署Flannel网络
下载分发flanneld二进制文件 (本次flanneld不使用Pod运行)
cd /opt/k8s/work
mkdir flannel
wget http://down.i4t.com/k8s1.14/flannel-v0.11.0-linux-amd64.tar.gz
tar -xzvf flannel-v0.11.0-linux-amd64.tar.gz -C flannel
分发二进制文件到所有集群的节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp flannel/{flanneld,mk-docker-opts.sh} root@${node_ip}:/opt/k8s/bin/
ssh root@${node_ip} "chmod +x /opt/k8s/bin/*"
done
创建Flannel证书和私钥
flanneld从etcd集群存取网段分配信息，而etcd集群开启了双向x509证书认证，所以需要为flannel生成证书和私钥
创建证书签名请求
cd /opt/k8s/work
cat > flanneld-csr.json <<EOF
{
"CN": "flanneld",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "4Paradigm"
}
]
}
EOF
生成证书和私钥
cfssl gencert -ca=/opt/k8s/work/ca.pem
-ca-key=/opt/k8s/work/ca-key.pem
-config=/opt/k8s/work/ca-config.json
-profile=kubernetes flanneld-csr.json | cfssljson -bare flanneld
ls flanneld*pem
将生成的证书和私钥分发到所有节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /etc/flanneld/cert"
scp flanneld*.pem root@${node_ip}:/etc/flanneld/cert
done
向etcd写入Pod网段信息
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
etcdctl
--endpoints=${ETCD_ENDPOINTS}
--ca-file=/opt/k8s/work/ca.pem
--cert-file=/opt/k8s/work/flanneld.pem
--key-file=/opt/k8s/work/flanneld-key.pem
mk ${FLANNEL_ETCD_PREFIX}/config '{"Network":"'${CLUSTER_CIDR}'", "SubnetLen": 21, "Backend": {"Type": "vxlan"}}'
注意:
flanneld当前版本v0.11.0不支持etcd v3，故使用etcd v2 API写入配置Key和网段数据；
写入的Pod网段${CLUSTER_CIDR}地址段(如/16)必须小于SubnetLen，必须与kube-controller-manager的–cluster-cidr参数一致
创建flanneld的启动文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > flanneld.service << EOF
[Unit]
Description=Flanneld overlay address etcd agent
After=network.target
After=network-online.target
Wants=network-online.target
After=etcd.service
Before=docker.service
[Service]
Type=notify
ExecStart=/opt/k8s/bin/flanneld \
-etcd-cafile=/etc/kubernetes/cert/ca.pem \
-etcd-certfile=/etc/flanneld/cert/flanneld.pem \
-etcd-keyfile=/etc/flanneld/cert/flanneld-key.pem \
-etcd-endpoints=${ETCD_ENDPOINTS} \
-etcd-prefix=${FLANNEL_ETCD_PREFIX} \
-iface=${IFACE} \
-ip-masq
ExecStartPost=/opt/k8s/bin/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/docker
Restart=always
RestartSec=5
StartLimitInterval=0
[Install]
WantedBy=multi-user.target
RequiredBy=docker.service
EOF
mk-docker-opts.sh 脚本将分配给 flanneld 的 Pod 子网段信息写入 /run/flannel/docker 文件，后续 docker 启动时使用这个文件中的环境变量配置 docker0 网桥；
flanneld 使用系统缺省路由所在的接口与其它节点通信，对于有多个网络接口（如内网和公网）的节点，可以用 -iface 参数指定通信接口;
flanneld 运行时需要 root 权限；
-ip-masq: flanneld 为访问 Pod 网络外的流量设置 SNAT 规则，同时将传递给 Docker 的变量 –ip-masq（/run/flannel/docker 文件中）设置为 false，这样 Docker 将不再创建 SNAT 规则； Docker 的 –ip-masq 为 true 时，创建的 SNAT 规则比较“暴力”：将所有本节点 Pod 发起的、访问非 docker0 接口的请求做 SNAT，这样访问其他节点 Pod 的请求来源 IP 会被设置为 flannel.1 接口的 IP，导致目的 Pod 看不到真实的来源 Pod IP。 flanneld 创建的 SNAT 规则比较温和，只对访问非 Pod 网段的请求做 SNAT。
分发启动文件到所有节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp flanneld.service root@${node_ip}:/etc/systemd/system/
done
启动flanneld服务
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable flanneld && systemctl restart flanneld"
done
检查启动结果
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl status flanneld|grep Active"
done
检查分配给flanneld的Pod网段信息
source /opt/k8s/bin/environment.sh
etcdctl
--endpoints=${ETCD_ENDPOINTS}
--ca-file=/etc/kubernetes/cert/ca.pem
--cert-file=/etc/flanneld/cert/flanneld.pem
--key-file=/etc/flanneld/cert/flanneld-key.pem
get ${FLANNEL_ETCD_PREFIX}/config
查看已分配的Pod子网网段列表
source /opt/k8s/bin/environment.sh
etcdctl
--endpoints=${ETCD_ENDPOINTS}
--ca-file=/etc/kubernetes/cert/ca.pem
--cert-file=/etc/flanneld/cert/flanneld.pem
--key-file=/etc/flanneld/cert/flanneld-key.pem
ls ${FLANNEL_ETCD_PREFIX}/subnets
查看某Pod网段对应节点IP和flannel接口地址
source /opt/k8s/bin/environment.sh
etcdctl
--endpoints=${ETCD_ENDPOINTS}
--ca-file=/etc/kubernetes/cert/ca.pem
--cert-file=/etc/flanneld/cert/flanneld.pem
--key-file=/etc/flanneld/cert/flanneld-key.pem
get ${FLANNEL_ETCD_PREFIX}/subnets/172.30.144.0-21
#后面节点IP需要根据我们查出来的地址进行修改
#比如我粘贴复制就报错了key not found 了
/kubernetes/network/subnets/172.30.144.0-21
/kubernetes/network/subnets/172.30.192.0-21
/kubernetes/network/subnets/172.30.208.0-21
/kubernetes/network/subnets/172.30.200.0-21
#这里我填写的是172.30.144.0-21
查看节点flannel网络信息
ip addr show
flannel.1网卡的地址为分配的pod自网段的第一个个IP (.0)，且是/32的地址
ip addr show|grep flannel.1
其余三个节点进行操作
到其它节点 Pod 网段请求都被转发到 flannel.1 网卡；
flanneld 根据 etcd 中子网段的信息，如 ${FLANNEL_ETCD_PREFIX}/subnets/172.30.80.0-21，来决定进请求发送给哪个节点的互联 IP；
验证各节点能通过 Pod 网段互通
在各节点上部署 flannel 后，检查是否创建了 flannel 接口(名称可能为 flannel0、flannel.0、flannel.1 等)：
其余1 2 3个节点
source /opt/k8s/bin/environment.sh
etcdctl
--endpoints=${ETCD_ENDPOINTS}
--ca-file=/etc/kubernetes/cert/ca.pem
--cert-file=/etc/flanneld/cert/flanneld.pem
--key-file=/etc/flanneld/cert/flanneld-key.pem
get ${FLANNEL_ETCD_PREFIX}/subnets/172.30.192.0-21
_______________________________________________________
source /opt/k8s/bin/environment.sh
etcdctl
--endpoints=${ETCD_ENDPOINTS}
--ca-file=/etc/kubernetes/cert/ca.pem
--cert-file=/etc/flanneld/cert/flanneld.pem
--key-file=/etc/flanneld/cert/flanneld-key.pem
get ${FLANNEL_ETCD_PREFIX}/subnets/172.30.208.0-21
________________________________________________________
source /opt/k8s/bin/environment.sh
etcdctl
--endpoints=${ETCD_ENDPOINTS}
--ca-file=/etc/kubernetes/cert/ca.pem
--cert-file=/etc/flanneld/cert/flanneld.pem
--key-file=/etc/flanneld/cert/flanneld-key.pem
get ${FLANNEL_ETCD_PREFIX}/subnets/172.30.200.0-21
查看各个节点的ip情况
ip addr show
ip addr show|grep flannel.1
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh ${node_ip} "/usr/sbin/ip addr show flannel.1|grep -w inet"
done
kube-apiserver 高可用
使用Nginx 4层透明代理功能实现k8s节点(master节点和worker节点)高可用访问kube-apiserver的步骤
控制节点的kube-controller-manager、kube-scheduler是多实例部署，所以只要一个实例正常，就可以保证集群高可用
集群内的Pod使用k8s服务域名kubernetes访问kube-apiserver，kube-dns会自动解析多个kube-apiserver节点的IP，所以也是高可用的
在每个Nginx进程，后端对接多个apiserver实例，Nginx对他们做健康检查和负载均衡
kubelet、kube-proxy、controller-manager、schedule通过本地nginx (监听我们vip 192.158.0.54)访问kube-apiserver，从而实现kube-apiserver高可用
下载编译nginx (k8s-01安装就可以，后面有拷贝步骤)
cd /opt/k8s/work
wget http://down.i4t.com/k8s1.14/nginx-1.15.3.tar.gz
tar -xzvf nginx-1.15.3.tar.gz
#编译
cd /opt/k8s/work/nginx-1.15.3
mkdir nginx-prefix
./configure --with-stream --without-http --prefix=$(pwd)/nginx-prefix --without-http_uwsgi_module
make && make install
#############
--without-http_scgi_module --without-http_fastcgi_module
--with-stream：开启 4 层透明转发(TCP Proxy)功能；
--without-xxx：关闭所有其他功能，这样生成的动态链接二进制程序依赖最小；
查看 nginx 动态链接的库：
ldd ./nginx-prefix/sbin/nginx
创建目录结构
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
mkdir -p /opt/k8s/kube-nginx/{conf,logs,sbin}
done
拷贝二进制程序到其他主机 (有报错执行2遍就可以)
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp /opt/k8s/work/nginx-1.15.3/nginx-prefix/sbin/nginx root@${node_ip}:/opt/k8s/kube-nginx/sbin/kube-nginx
ssh root@${node_ip} "chmod a+x /opt/k8s/kube-nginx/sbin/*"
ssh root@${node_ip} "mkdir -p /opt/k8s/kube-nginx/{conf,logs,sbin}"
sleep 3
done
配置Nginx文件，开启4层透明转发
cd /opt/k8s/work
cat > kube-nginx.conf <<EOF
worker_processes 1;
events {
worker_connections 1024;
}
stream {
upstream backend {
hash $remote_addr consistent;
server 192.168.191.10:6443 max_fails=3 fail_timeout=30s;
server 192.168.191.11:6443 max_fails=3 fail_timeout=30s;
server 192.168.191.12:6443 max_fails=3 fail_timeout=30s;
}
server {
listen *:8443;
proxy_connect_timeout 1s;
proxy_pass backend;
}
}
EOF
#这里需要将server替换我们自己的地址
分发配置文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-nginx.conf root@${node_ip}:/opt/k8s/kube-nginx/conf/kube-nginx.conf
done
配置Nginx启动文件
cd /opt/k8s/work
cat > kube-nginx.service <<EOF
[Unit]
Description=kube-apiserver nginx proxy
After=network.target
After=network-online.target
Wants=network-online.target
[Service]
Type=forking
ExecStartPre=/opt/k8s/kube-nginx/sbin/kube-nginx -c /opt/k8s/kube-nginx/conf/kube-nginx.conf -p /opt/k8s/kube-nginx -t
ExecStart=/opt/k8s/kube-nginx/sbin/kube-nginx -c /opt/k8s/kube-nginx/conf/kube-nginx.conf -p /opt/k8s/kube-nginx
ExecReload=/opt/k8s/kube-nginx/sbin/kube-nginx -c /opt/k8s/kube-nginx/conf/kube-nginx.conf -p /opt/k8s/kube-nginx -s reload
PrivateTmp=true
Restart=always
RestartSec=5
StartLimitInterval=0
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
分发nginx启动文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-nginx.service root@${node_ip}:/etc/systemd/system/
done
启动 kube-nginx 服务
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-nginx && systemctl start kube-nginx"
done
检查 kube-nginx 服务运行状态
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl status kube-nginx |grep 'Active:'"
done
KeepLived 部署
前面我们也说了，高可用方案需要一个VIP，供集群内部访问
在所有master节点安装keeplived
yum install -y keepalived
接下来我们要配置keeplive服务
192.168.0.50配置
cat > /etc/keepalived/keepalived.conf <<EOF
! Configuration File for keepalived
global_defs {
router_id 192.168.191.10
}
vrrp_script chk_nginx {
script "/etc/keepalived/check_port.sh 8443"
interval 2
weight -20
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 251
priority 100
advert_int 1
mcast_src_ip 192.168.191.10
nopreempt
authentication {
auth_type PASS
auth_pass 11111111
}
track_script {
chk_nginx
}
virtual_ipaddress {
192.168.191.13
}
}
EOF
192.168.0.50 为节点IP，192.168.0.54位VIP
将配置拷贝到其他节点，并替换相关IP
for node_ip in 192.168.191.10 192.168.191.11 192.168.191.12
do
echo ">>> ${node_ip}"
scp /etc/keepalived/keepalived.conf $node_ip:/etc/keepalived/keepalived.conf
done
#替换IP
ssh root@192.168.191.10 sed -i 's#192.168.191.10#192.168.191.11#g' /etc/keepalived/keepalived.conf
ssh root@192.168.191.12 sed -i 's#192.168.191.10#192.168.191.12#g' /etc/keepalived/keepalived.conf
#192.168.0.50不替换是因为已经修改好了
创建健康检查脚本 (做到了这里)
vim /opt/check_port.sh
CHK_PORT=$1
if [ -n "$CHK_PORT" ];then
PORT_PROCESS=`ss -lt|grep $CHK_PORT|wc -l`
if [ $PORT_PROCESS -eq 0 ];then
echo "Port $CHK_PORT Is Not Used,End."
exit 1
fi
else
echo "Check Port Cant Be Empty!"1
fi
启动keeplived
for NODE in k8s-01 k8s-02 k8s-03; do
echo "--- $NODE ---"
scp -r /opt/check_port.sh $NODE:/etc/keepalived/
ssh $NODE 'systemctl enable --now keepalived.service'
done
启动完毕后ping 192.168.0.54 (VIP)
因为要快速搭建完毕 不能浪费太多时间 所以这里的keepalived高可用暂时是没成功的
找时间改下配置文件即可,一些参数稍微一改改就可以启动成功 主要是做到现在还没有
用到整个Keepalived集群的作用 暂时搁置 .
部署master节点
kubernetes master节点运行组件如下:kube-apiserver、kube-scheduler、kube-controller-manager、kube-nginx
kube-apiserver、kube-scheduler、kube-controller-manager均以多实例模式运行
kube-scheduler和kube-controller-manager会自动选举一个leader实例，其他实例处于阻塞模式，当leader挂了后，重新选举产生的leader，从而保证服务可用性
kube-apiserver是无状态的，需要通过kube-nginx进行代理访问，从而保证服务可用性
以下操作都在K8s-01操作
下载kubernetes二进制包，并分发到所有master节点
cd /opt/k8s/work
wget http://down.i4t.com/k8s1.14/kubernetes-server-linux-amd64.tar.gz
tar -xzvf kubernetes-server-linux-amd64.tar.gz
cd kubernetes
tar -xzvf kubernetes-src.tar.gz
将压缩包的文件拷贝到所有master节点上
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kubernetes/server/bin/kube-apiserver root@${node_ip}:/opt/k8s/bin/
scp kubernetes/server/bin/{apiextensions-apiserver,cloud-controller-manager,kube-controller-manager,kube-proxy,kube-scheduler,kubeadm,kubectl,kubelet,mounter} root@${node_ip}:/opt/k8s/bin/
ssh root@${node_ip} "chmod +x /opt/k8s/bin/*"
done
#同时将kubelet kube-proxy拷贝到所有节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
scp kubernetes/server/bin/{kubelet,kube-proxy} root@${node_ip}:/opt/k8s/bin/
ssh root@${node_ip} "chmod +x /opt/k8s/bin/*"
done
创建Kubernetes 证书和私钥
创建签证签名请求
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > kubernetes-csr.json <<EOF
{
"CN": "kubernetes",
"hosts": [
"127.0.0.1",
"192.168.191.10",
"192.168.191.11",
"192.168.191.12",
"192.168.191.13",
"10.254.0.1",
"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": "4Paradigm"
}
]
}
EOF
#需要将集群的所有IP及VIP添加进去
#如果要添加注意最后的逗号，不要忘记添加，否则下一步报错
hosts 字段指定授权使用该证书的IP和域名列表，这里列出了master节点IP、kubernetes服务的IP和域名
kubernetes serviceIP是apiserver自动创建的，一般是–service-cluster-ip-range参数指定的网段的第一个IP
$ kubectl get svc kubernetes
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.254.0.1 443/TCP 31d
#目前我们是看不到
生成证书和私钥
cfssl gencert -ca=/opt/k8s/work/ca.pem
-ca-key=/opt/k8s/work/ca-key.pem
-config=/opt/k8s/work/ca-config.json
-profile=kubernetes kubernetes-csr.json | cfssljson -bare kubernetes
ls kubernetes*pem
将生成的证书和私钥文件拷贝到所有master节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p /etc/kubernetes/cert"
scp kubernetes*.pem root@${node_ip}:/etc/kubernetes/cert/
done
创建加密配置文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > encryption-config.yaml <<EOF
kind: EncryptionConfig
apiVersion: v1
resources:
- resources:
- secrets
providers:
- aescbc:
keys:
- name: key1
secret: ${ENCRYPTION_KEY}
- identity: {}
EOF
将加密配置文件拷贝到master节点的/etc/kubernetes目录下
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp encryption-config.yaml root@${node_ip}:/etc/kubernetes/
done
创建审计策略文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > audit-policy.yaml <<EOF
apiVersion: audit.k8s.io/v1beta1
kind: Policy
rules:
# The following requests were manually identified as high-volume and low-risk, so drop them.
- level: None
resources:
- group: ""
resources:
- endpoints
- services
- services/status
users:
- 'system:kube-proxy'
verbs:
- watch
- level: None
resources:
- group: ""
resources:
- nodes
- nodes/status
userGroups:
- 'system:nodes'
verbs:
- get
- level: None
namespaces:
- kube-system
resources:
- group: ""
resources:
- endpoints
users:
- 'system:kube-controller-manager'
- 'system:kube-scheduler'
- 'system:serviceaccount:kube-system:endpoint-controller'
verbs:
- get
- update
- level: None
resources:
- group: ""
resources:
- namespaces
- namespaces/status
- namespaces/finalize
users:
- 'system:apiserver'
verbs:
- get
# Don't log HPA fetching metrics.
- level: None
resources:
- group: metrics.k8s.io
users:
- 'system:kube-controller-manager'
verbs:
- get
- list
# Don't log these read-only URLs.
- level: None
nonResourceURLs:
- '/healthz*'
- /version
- '/swagger*'
# Don't log events requests.
- level: None
resources:
- group: ""
resources:
- events
# node and pod status calls from nodes are high-volume and can be large, don't log responses for expected updates from nodes
- level: Request
omitStages:
- RequestReceived
resources:
- group: ""
resources:
- nodes/status
- pods/status
users:
- kubelet
- 'system:node-problem-detector'
- 'system:serviceaccount:kube-system:node-problem-detector'
verbs:
- update
- patch
- level: Request
omitStages:
- RequestReceived
resources:
- group: ""
resources:
- nodes/status
- pods/status
userGroups:
- 'system:nodes'
verbs:
- update
- patch
# deletecollection calls can be large, don't log responses for expected namespace deletions
- level: Request
omitStages:
- RequestReceived
users:
- 'system:serviceaccount:kube-system:namespace-controller'
verbs:
- deletecollection
# Secrets, ConfigMaps, and TokenReviews can contain sensitive & binary data,
# so only log at the Metadata level.
- level: Metadata
omitStages:
- RequestReceived
resources:
- group: ""
resources:
- secrets
- configmaps
- group: authentication.k8s.io
resources:
- tokenreviews
# Get repsonses can be large; skip them.
- level: Request
omitStages:
- RequestReceived
resources:
- group: ""
- group: admissionregistration.k8s.io
- group: apiextensions.k8s.io
- group: apiregistration.k8s.io
- group: apps
- group: authentication.k8s.io
- group: authorization.k8s.io
- group: autoscaling
- group: batch
- group: certificates.k8s.io
- group: extensions
- group: metrics.k8s.io
- group: networking.k8s.io
- group: policy
- group: rbac.authorization.k8s.io
- group: scheduling.k8s.io
- group: settings.k8s.io
- group: storage.k8s.io
verbs:
- get
- list
- watch
# Default level for known APIs
- level: RequestResponse
omitStages:
- RequestReceived
resources:
- group: ""
- group: admissionregistration.k8s.io
- group: apiextensions.k8s.io
- group: apiregistration.k8s.io
- group: apps
- group: authentication.k8s.io
- group: authorization.k8s.io
- group: autoscaling
- group: batch
- group: certificates.k8s.io
- group: extensions
- group: metrics.k8s.io
- group: networking.k8s.io
- group: policy
- group: rbac.authorization.k8s.io
- group: scheduling.k8s.io
- group: settings.k8s.io
- group: storage.k8s.io
# Default level for all other requests.
- level: Metadata
omitStages:
- RequestReceived
EOF
分发审计策略文件：
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp audit-policy.yaml root@${node_ip}:/etc/kubernetes/audit-policy.yaml
done
创建证书签名请求
cat > proxy-client-csr.json <<EOF
{
"CN": "aggregator",
"hosts": [],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "4Paradigm"
}
]
}
EOF
CN名称需要位于kube-apiserver的–requestherader-allowed-names参数中，否则后续访问metrics时会提示权限不足
生成证书和私钥
cfssl gencert -ca=/etc/kubernetes/cert/ca.pem
-ca-key=/etc/kubernetes/cert/ca-key.pem
-config=/etc/kubernetes/cert/ca-config.json
-profile=kubernetes proxy-client-csr.json | cfssljson -bare proxy-client
ls proxy-client*.pem
将生成的证书和私钥文件拷贝到master节点
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp proxy-client*.pem root@${node_ip}:/etc/kubernetes/cert/
done
创建kube-apiserver启动文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > kube-apiserver.service.template <<EOF
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
[Service]
WorkingDirectory=${K8S_DIR}/kube-apiserver
ExecStart=/opt/k8s/bin/kube-apiserver \
--advertise-address=##NODE_IP## \
--default-not-ready-toleration-seconds=360 \
--default-unreachable-toleration-seconds=360 \
--feature-gates=DynamicAuditing=true \
--max-mutating-requests-inflight=2000 \
--max-requests-inflight=4000 \
--default-watch-cache-size=200 \
--delete-collection-workers=2 \
--encryption-provider-config=/etc/kubernetes/encryption-config.yaml \
--etcd-cafile=/etc/kubernetes/cert/ca.pem \
--etcd-certfile=/etc/kubernetes/cert/kubernetes.pem \
--etcd-keyfile=/etc/kubernetes/cert/kubernetes-key.pem \
--etcd-servers=${ETCD_ENDPOINTS} \
--bind-address=##NODE_IP## \
--secure-port=6443 \
--tls-cert-file=/etc/kubernetes/cert/kubernetes.pem \
--tls-private-key-file=/etc/kubernetes/cert/kubernetes-key.pem \
--insecure-port=0 \
--audit-dynamic-configuration \
--audit-log-maxage=15 \
--audit-log-maxbackup=3 \
--audit-log-maxsize=100 \
--audit-log-truncate-enabled \
--audit-log-path=${K8S_DIR}/kube-apiserver/audit.log \
--audit-policy-file=/etc/kubernetes/audit-policy.yaml \
--profiling \
--anonymous-auth=false \
--client-ca-file=/etc/kubernetes/cert/ca.pem \
--enable-bootstrap-token-auth \
--requestheader-allowed-names="aggregator" \
--requestheader-client-ca-file=/etc/kubernetes/cert/ca.pem \
--requestheader-extra-headers-prefix="X-Remote-Extra-" \
--requestheader-group-headers=X-Remote-Group \
--requestheader-username-headers=X-Remote-User \
--service-account-key-file=/etc/kubernetes/cert/ca.pem \
--authorization-mode=Node,RBAC \
--runtime-config=api/all=true \
--enable-admission-plugins=NodeRestriction \
--allow-privileged=true \
--apiserver-count=3 \
--event-ttl=168h \
--kubelet-certificate-authority=/etc/kubernetes/cert/ca.pem \
--kubelet-client-certificate=/etc/kubernetes/cert/kubernetes.pem \
--kubelet-client-key=/etc/kubernetes/cert/kubernetes-key.pem \
--kubelet-https=true \
--kubelet-timeout=10s \
--proxy-client-cert-file=/etc/kubernetes/cert/proxy-client.pem \
--proxy-client-key-file=/etc/kubernetes/cert/proxy-client-key.pem \
--service-cluster-ip-range=${SERVICE_CIDR} \
--service-node-port-range=${NODE_PORT_RANGE} \
--logtostderr=true \
--v=2
Restart=on-failure
RestartSec=10
Type=notify
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
为各个节点创建和分发kube-apiserver启动文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for (( i=0; i < 3; i++ )) #这里是三个节点所以为3,请根据实际情况修改,后边不在提示,同理
do
sed -e "s/##NODE_NAME##/${MASTER_NAMES[i]}/" -e "s/##NODE_IP##/${MASTER_IPS[i]}/" kube-apiserver.service.template > kube-apiserver-${MASTER_IPS[i]}.service
done
ls kube-apiserver*.service
分发apiserver启动文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-apiserver-${node_ip}.service root@${node_ip}:/etc/systemd/system/kube-apiserver.service
done
启动apiserver
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p ${K8S_DIR}/kube-apiserver"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-apiserver && systemctl restart kube-apiserver"
done
检查服务是否正常
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl status kube-apiserver |grep 'Active:'"
done
确保状态为active (running)，否则查看日志，确认原因
journalctl -u kube-apiserver
打印kube-apiserver写入etcd数据
source /opt/k8s/bin/environment.sh
ETCDCTL_API=3 etcdctl
--endpoints=${ETCD_ENDPOINTS}
--cacert=/opt/k8s/work/ca.pem
--cert=/opt/k8s/work/etcd.pem
--key=/opt/k8s/work/etcd-key.pem
get /registry/ --prefix --keys-only
检查kube-apiserver监听的端口
yum install -y net-tools
netstat -lntup|grep kube
检查集群信息
kubectl cluster-info
Kubernetes master is running at https://192.168.191.13:8443
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
[root@k8s-01 work]# kubectl get all --all-namespaces
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default service/kubernetes ClusterIP 10.254.0.1 <none> 443/TCP 4m39s
[root@k8s-01 work]# kubectl get componentstatuses
NAME STATUS MESSAGE ERROR
controller-manager Unhealthy Get http://127.0.0.1:10252/healthz: dial tcp 127.0.0.1:10252: connect: connection refused
scheduler Unhealthy Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: connect: connection refused
etcd-1 Healthy {"health":"true"}
etcd-0 Healthy {"health":"true"}
etcd-2 Healthy {"health":"true"}
如果提示有报错，请检查~/.kube/config以及配置证书是否有问题
在执行kubectl命令时，apiserver会将请求转发到kubelet的https端口。这里定义的RBAC规则，授权apiserver使用的证书(kubernetes.pem)用户名(CN:kubernetes)访问kubelet API的权限
kubectl create clusterrolebinding kube-apiserver:kubelet-apis --clusterrole=system:kubelet-api-admin --user kubernetes
部署高可用kube-controller-manager集群
该集群包含三个节点，启动后通过竞争选举机制产生一个leader节点，其他节点为阻塞状态。当leader节点不可用时，阻塞节点将会在此选举产生新的leader，从而保证服务的高可用。为保证通信安全，这里采用x509证书和私钥，kube-controller-manager在与apiserver的安全端口（http 10252）通信使用；
创建kube-controller-manager证书和私钥
创建证书签名请求
cd /opt/k8s/work
cat > kube-controller-manager-csr.json <<EOF
{
"CN": "system:kube-controller-manager",
"key": {
"algo": "rsa",
"size": 2048
},
"hosts": [
"127.0.0.1",
"192.168.191.10",
"192.168.191.11",
"192.168.191.12"
],
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "system:kube-controller-manager",
"OU": "4Paradigm"
}
]
}
EOF
#这里的IP地址为master ip
host列表包含所有的kube-controller-manager节点IP(VIP不需要输入)
CN和O均为system:kube-controller-manager，kubernetes内置的ClusterRoleBindings system:kube-controller-manager赋予kube-controller-manager工作所需权限
生成证书和私钥
cd /opt/k8s/work
cfssl gencert -ca=/opt/k8s/work/ca.pem
-ca-key=/opt/k8s/work/ca-key.pem
-config=/opt/k8s/work/ca-config.json
-profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager
ls kube-controller-manager*pem
将生成的证书和私钥分发到所有master节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-controller-manager*.pem root@${node_ip}:/etc/kubernetes/cert/
done
创建和分发kubeconfig文件
kube-controller-manager使用kubeconfig文件访问apiserver
该文件提供了apiserver地址、嵌入的CA证书和kube-controller-manager证书
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
kubectl config set-cluster kubernetes
--certificate-authority=/opt/k8s/work/ca.pem
--embed-certs=true
--server=${KUBE_APISERVER}
--kubeconfig=kube-controller-manager.kubeconfig
kubectl config set-credentials system:kube-controller-manager
--client-certificate=kube-controller-manager.pem
--client-key=kube-controller-manager-key.pem
--embed-certs=true
--kubeconfig=kube-controller-manager.kubeconfig
kubectl config set-context system:kube-controller-manager
--cluster=kubernetes
--user=system:kube-controller-manager
--kubeconfig=kube-controller-manager.kubeconfig
kubectl config use-context system:kube-controller-manager --kubeconfig=kube-controller-manager.kubeconfig
分发kubeconfig到所有master节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-controller-manager.kubeconfig root@${node_ip}:/etc/kubernetes/
done
创建kube-controller-manager启动文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > kube-controller-manager.service.template <<EOF
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
WorkingDirectory=${K8S_DIR}/kube-controller-manager
ExecStart=/opt/k8s/bin/kube-controller-manager \
--profiling \
--cluster-name=kubernetes \
--controllers=*,bootstrapsigner,tokencleaner \
--kube-api-qps=1000 \
--kube-api-burst=2000 \
--leader-elect \
--use-service-account-credentials\
--concurrent-service-syncs=2 \
--bind-address=0.0.0.0 \
#--secure-port=10252 \
--tls-cert-file=/etc/kubernetes/cert/kube-controller-manager.pem \
--tls-private-key-file=/etc/kubernetes/cert/kube-controller-manager-key.pem \
#--port=0 \
--authentication-kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \
--client-ca-file=/etc/kubernetes/cert/ca.pem \
--requestheader-allowed-names="" \
--requestheader-client-ca-file=/etc/kubernetes/cert/ca.pem \
--requestheader-extra-headers-prefix="X-Remote-Extra-" \
--requestheader-group-headers=X-Remote-Group \
--requestheader-username-headers=X-Remote-User \
--authorization-kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \
--cluster-signing-cert-file=/etc/kubernetes/cert/ca.pem \
--cluster-signing-key-file=/etc/kubernetes/cert/ca-key.pem \
--experimental-cluster-signing-duration=876000h \
--horizontal-pod-autoscaler-sync-period=10s \
--concurrent-deployment-syncs=10 \
--concurrent-gc-syncs=30 \
--node-cidr-mask-size=24 \
--service-cluster-ip-range=${SERVICE_CIDR} \
--pod-eviction-timeout=6m \
--terminated-pod-gc-threshold=10000 \
--root-ca-file=/etc/kubernetes/cert/ca.pem \
--service-account-private-key-file=/etc/kubernetes/cert/ca-key.pem \
--kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \
--logtostderr=true \
--v=2
Restart=on-failure
RestartSec=5
[Install]
WantedBy=multi-user.target
EOF
替换启动文件，并分发脚本
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for (( i=0; i < 3; i++ ))
do
sed -e "s/##NODE_NAME##/${MASTER_NAMES[i]}/" -e "s/##NODE_IP##/${MASTER_IPS[i]}/" kube-controller-manager.service.template > kube-controller-manager-${MASTER_IPS[i]}.service
done
ls kube-controller-manager*.service
分发到所有master节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-controller-manager-${node_ip}.service root@${node_ip}:/etc/systemd/system/kube-controller-manager.service
done
启动服务
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p ${K8S_DIR}/kube-controller-manager"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-controller-manager && systemctl restart kube-controller-manager"
done
检查运行状态
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl status kube-controller-manager|grep Active"
done
检查服务状态
netstat -lnpt | grep kube-cont
kube-controller-manager 创建权限
ClusteRole system:kube-controller-manager的权限太小，只能创建secret、serviceaccount等资源,将controller的权限分散到ClusterRole system:controller:xxx中
kubectl describe clusterrole system:kube-controller-manager
Name: system:kube-controller-manager
Labels: kubernetes.io/bootstrapping=rbac-defaults
Annotations: rbac.authorization.kubernetes.io/autoupdate: true
PolicyRule:
Resources Non-Resource URLs Resource Names Verbs
--------- ----------------- -------------- -----
secrets [] [] [create delete get update]
endpoints [] [] [create get update]
serviceaccounts [] [] [create get update]
events [] [] [create patch update]
tokenreviews.authentication.k8s.io [] [] [create]
subjectaccessreviews.authorization.k8s.io [] [] [create]
configmaps [] [] [get]
namespaces [] [] [get]
*.* [] [] [list watch]
需要在 kube-controller-manager 的启动参数中添加 –use-service-account-credentials=true 参数，这样 main controller 会为各 controller 创建对应的 ServiceAccount XXX-controller。内置的 ClusterRoleBinding system:controller:XXX 将赋予各 XXX-controller ServiceAccount 对应的 ClusterRole system:controller:XXX 权限。
kubectl get clusterrole|grep controller
system:controller:attachdetach-controller 179m
system:controller:certificate-controller 179m
system:controller:clusterrole-aggregation-controller 179m
system:controller:cronjob-controller 179m
system:controller:daemon-set-controller 179m
system:controller:deployment-controller 179m
system:controller:disruption-controller 179m
system:controller:endpoint-controller 179m
system:controller:expand-controller 179m
system:controller:generic-garbage-collector 179m
system:controller:horizontal-pod-autoscaler 179m
system:controller:job-controller 179m
system:controller:namespace-controller 179m
system:controller:node-controller 179m
system:controller:persistent-volume-binder 179m
system:controller:pod-garbage-collector 179m
system:controller:pv-protection-controller 179m
system:controller:pvc-protection-controller 179m
system:controller:replicaset-controller 179m
system:controller:replication-controller 179m
system:controller:resourcequota-controller 179m
system:controller:route-controller 179m
system:controller:service-account-controller 179m
system:controller:service-controller 179m
system:controller:statefulset-controller 179m
system:controller:ttl-controller 179m
system:kube-controller-manager 179m
以 deployment controller 为例：
kubectl describe clusterrole system:controller:deployment-controller
Name: system:controller:deployment-controller
Labels: kubernetes.io/bootstrapping=rbac-defaults
Annotations: rbac.authorization.kubernetes.io/autoupdate: true
PolicyRule:
Resources Non-Resource URLs Resource Names Verbs
--------- ----------------- -------------- -----
replicasets.apps [] [] [create delete get list patch update watch]
replicasets.extensions [] [] [create delete get list patch update watch]
events [] [] [create patch update]
pods [] [] [get list update watch]
deployments.apps [] [] [get list update watch]
deployments.extensions [] [] [get list update watch]
deployments.apps/finalizers [] [] [update]
deployments.apps/status [] [] [update]
deployments.extensions/finalizers [] [] [update]
deployments.extensions/status [] [] [update]
查看当前的 leader
kubectl get endpoints kube-controller-manager --namespace=kube-system -o yaml
apiVersion: v1
kind: Endpoints
metadata:
annotations:
control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"k8s-01_c7e8ce75-5df6-11ea-b908-000c299ed09c","leaseDurationSeconds":15,"acquireTime":"2020-03-04T09:01:48Z","renewTime":"2020-03-04T09:10:31Z","leaderTransitions":0}'
creationTimestamp: "2020-03-04T09:01:48Z"
name: kube-controller-manager
namespace: kube-system
resourceVersion: "3822"
selfLink: /api/v1/namespaces/kube-system/endpoints/kube-controller-manager
uid: c7f3d30e-5df6-11ea-9740-000c299ed09c
部署高可用kube-scheduler
创建 kube-scheduler 证书和私钥
创建证书签名请求：
cd /opt/k8s/work
cat > kube-scheduler-csr.json <<EOF
{
"CN": "system:kube-scheduler",
"hosts": [
"127.0.0.1",
"192.168.0.50",
"192.168.0.51",
"192.168.0.52"
],
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "system:kube-scheduler",
"OU": "4Paradigm"
}
]
}
EOF
生成证书和私钥：
cd /opt/k8s/work
cfssl gencert -ca=/opt/k8s/work/ca.pem
-ca-key=/opt/k8s/work/ca-key.pem
-config=/opt/k8s/work/ca-config.json
-profile=kubernetes kube-scheduler-csr.json | cfssljson -bare kube-scheduler
ls kube-scheduler*pem
将生成的证书和私钥分发到所有 master 节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-scheduler*.pem root@${node_ip}:/etc/kubernetes/cert/
done
创建和分发 kubeconfig 文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
kubectl config set-cluster kubernetes
--certificate-authority=/opt/k8s/work/ca.pem
--embed-certs=true
--server=${KUBE_APISERVER}
--kubeconfig=kube-scheduler.kubeconfig
kubectl config set-credentials system:kube-scheduler
--client-certificate=kube-scheduler.pem
--client-key=kube-scheduler-key.pem
--embed-certs=true
--kubeconfig=kube-scheduler.kubeconfig
kubectl config set-context system:kube-scheduler
--cluster=kubernetes
--user=system:kube-scheduler
--kubeconfig=kube-scheduler.kubeconfig
kubectl config use-context system:kube-scheduler --kubeconfig=kube-scheduler.kubeconfig
分发 kubeconfig 到所有 master 节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-scheduler.kubeconfig root@${node_ip}:/etc/kubernetes/
done
创建 kube-scheduler 配置文件
cd /opt/k8s/work
cat >kube-scheduler.yaml.template <<EOF
apiVersion: kubescheduler.config.k8s.io/v1alpha1
kind: KubeSchedulerConfiguration
bindTimeoutSeconds: 600
clientConnection:
burst: 200
kubeconfig: "/etc/kubernetes/kube-scheduler.kubeconfig"
qps: 100
enableContentionProfiling: false
enableProfiling: true
hardPodAffinitySymmetricWeight: 1
healthzBindAddress: 127.0.0.1:10251
leaderElection:
leaderElect: true
metricsBindAddress: ##NODE_IP##:10251
EOF
替换模板文件中的变量：
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for (( i=0; i < 3; i++ ))
do
sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-scheduler.yaml.template > kube-scheduler-${NODE_IPS[i]}.yaml
done
ls kube-scheduler*.yaml
分发 kube-scheduler 配置文件到所有 master 节点：
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-scheduler-${node_ip}.yaml root@${node_ip}:/etc/kubernetes/kube-scheduler.yaml
done
创建kube-scheduler启动文件
cd /opt/k8s/work
cat > kube-scheduler.service.template <<EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
WorkingDirectory=${K8S_DIR}/kube-scheduler
ExecStart=/opt/k8s/bin/kube-scheduler \
--config=/etc/kubernetes/kube-scheduler.yaml \
--bind-address=##NODE_IP## \
--secure-port=10259 \
--port=0 \
--tls-cert-file=/etc/kubernetes/cert/kube-scheduler.pem \
--tls-private-key-file=/etc/kubernetes/cert/kube-scheduler-key.pem \
--authentication-kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \
--client-ca-file=/etc/kubernetes/cert/ca.pem \
--requestheader-allowed-names="" \
--requestheader-client-ca-file=/etc/kubernetes/cert/ca.pem \
--requestheader-extra-headers-prefix="X-Remote-Extra-" \
--requestheader-group-headers=X-Remote-Group \
--requestheader-username-headers=X-Remote-User \
--authorization-kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \
--logtostderr=true \
--v=2
Restart=always
RestartSec=5
StartLimitInterval=0
[Install]
WantedBy=multi-user.target
EOF
分发配置文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for (( i=0; i < 3; i++ ))
do
sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-scheduler.service.template > kube-scheduler-${NODE_IPS[i]}.service
done
ls kube-scheduler*.service
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
scp kube-scheduler-${node_ip}.service root@${node_ip}:/etc/systemd/system/kube-scheduler.service
done
启动kube-scheduler
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p ${K8S_DIR}/kube-scheduler"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-scheduler && systemctl restart kube-scheduler"
done
检查服务运行状态
source /opt/k8s/bin/environment.sh
for node_ip in ${MASTER_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl status kube-scheduler|grep Active"
done
查看输出的 metrics
注意：以下命令在 kube-scheduler 节点上执行。
kube-scheduler 监听 10251 和 10251 端口：
10251：接收 http 请求，非安全端口，不需要认证授权；
10259：接收 https 请求，安全端口，需要认证授权；
两个接口都对外提供 /metrics 和 /healthz 的访问。
查看输出的 metrics
curl -s http://192.168.191.10:10251/metrics|head
# HELP apiserver_audit_event_total Counter of audit events generated and sent to the audit backend.
# TYPE apiserver_audit_event_total counter
apiserver_audit_event_total 0
# HELP apiserver_audit_requests_rejected_total Counter of apiserver requests rejected due to an error in audit logging backend.
# TYPE apiserver_audit_requests_rejected_total counter
apiserver_audit_requests_rejected_total 0
# HELP apiserver_client_certificate_expiration_seconds Distribution of the remaining lifetime on the certificate used to authenticate a request.
# TYPE apiserver_client_certificate_expiration_seconds histogram
apiserver_client_certificate_expiration_seconds_bucket{le="0"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="1800"} 0
查看当前leader
kubectl get endpoints kube-scheduler --namespace=kube-system -o yaml
apiVersion: v1
kind: Endpoints
metadata:
annotations:
control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"k8s-02_eb8587c1-5df8-11ea-993f-000c29be2e5a","leaseDurationSeconds":15,"acquireTime":"2020-03-04T09:21:12Z","renewTime":"2020-03-04T09:28:29Z","leaderTransitions":1}'
creationTimestamp: "2020-03-04T09:17:07Z"
name: kube-scheduler
namespace: kube-system
resourceVersion: "4973"
selfLink: /api/v1/namespaces/kube-system/endpoints/kube-scheduler
uid: ebb878a8-5df8-11ea-9740-000c299ed09c
work节点安装
kubernetes work节点运行如下组件: >docker、kubelet、kube-proxy、flanneld、kube-nginx
前面已经安装flanneld这就不在安装了
安装依赖包
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "yum install -y epel-release"
ssh root@${node_ip} "yum install -y conntrack ipvsadm ntp ntpdate ipset jq iptables curl sysstat libseccomp && modprobe ip_vs "
done
部署Docker组件
我们在所有节点安装docker，这里使用阿里云的yum安装
Docker步骤需要在所有节点安装
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum makecache fast
yum -y install docker-ce
创建配置文件
mkdir -p /etc/docker/
cat > /etc/docker/daemon.json <<EOF
{
"exec-opts": ["native.cgroupdriver=systemd"],
"registry-mirrors": ["https://hjvrgh7a.mirror.aliyuncs.com"],
"log-driver": "json-file",
"log-opts": {
"max-size": "100m"
},
"storage-driver": "overlay2"
}
EOF
#这里配置当时镜像加速器,可以不进行配置，但是建议配置
要添加我们harbor仓库需要在添加下面一行
"insecure-registries": ["harbor.i4t.com"],
默认docker hub需要https协议，使用上面配置不需要配置https
修改Docker启动参数
这里需要在所有的节点上修改docker配置！！
cat /usr/lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
BindsTo=containerd.service
After=network-online.target firewalld.service containerd.service
Wants=network-online.target
Requires=docker.socket
[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd $DOCKER_NETWORK_OPTIONS -H fd:// --containerd=/run/containerd/containerd.sock
EnvironmentFile=-/run/flannel/docker
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
# Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
# Both the old, and new location are accepted by systemd 229 and up, so using the old location
# to make them work for either version of systemd.
StartLimitBurst=3
# Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
# Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
# this option work for either version of systemd.
StartLimitInterval=60s
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
# Comment TasksMax if your systemd version does not support it.
# Only systemd 226 and above support this option.
TasksMax=infinity
# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes
# kill only the docker process, not all processes in the cgroup
KillMode=process
[Install]
WantedBy=multi-user.target
启动 docker 服务
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable docker && systemctl restart docker"
done
检查服务运行状态
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl status docker|grep Active"
done
检查 docker0 网桥
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "/usr/sbin/ip addr show flannel.1 && /usr/sbin/ip addr show docker0"
done
查看 docker 的状态信息
docker info
#查看docker版本以及存储引擎是否是overlay2
部署kubelet组件
kubelet运行在每个worker节点上，接收kube-apiserver发送的请求，管理Pod容器，执行交互命令
kubelet启动时自动向kube-apiserver注册节点信息，内置的cAdivsor统计和监控节点的资源使用资源情况。为确保安全，部署时关闭了kubelet的非安全http端口，对请求进行认证和授权，拒绝未授权的访问
创建kubelet bootstrap kubeconfig文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
# 创建 token
export BOOTSTRAP_TOKEN=$(kubeadm token create
--description kubelet-bootstrap-token
--groups system:bootstrappers:${node_name}
--kubeconfig ~/.kube/config)
# 设置集群参数
kubectl config set-cluster kubernetes
--certificate-authority=/etc/kubernetes/cert/ca.pem
--embed-certs=true
--server=${KUBE_APISERVER}
--kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig
# 设置客户端认证参数
kubectl config set-credentials kubelet-bootstrap
--token=${BOOTSTRAP_TOKEN}
--kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig
# 设置上下文参数
kubectl config set-context default
--cluster=kubernetes
--user=kubelet-bootstrap
--kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig
# 设置默认上下文
kubectl config use-context default --kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig
done
###向kubeconfig写入的是token，bootstrap结束后kube-controller-manager为kubelet创建client和server证书
查看kubeadm为各个节点创建的token
kubeadm token list --kubeconfig ~/.kube/config
TOKEN TTL EXPIRES USAGES DESCRIPTION EXTRA GROUPS
arc548.wgpkrn86fhivaq95 23h 2020-03-06T14:43:57+08:00 authentication,signing kubelet-bootstrap-token system:bootstrappers:k8s-04
eg8wj5.233dpqcbtxfqk29g 23h 2020-03-06T14:43:57+08:00 authentication,signing kubelet-bootstrap-token system:bootstrappers:k8s-02
k555eq.inr6by091mq0l2z9 23h 2020-03-06T14:43:56+08:00 authentication,signing kubelet-bootstrap-token system:bootstrappers:k8s-01
zfcoqb.ghrdvb2urbb90xwh 23h 2020-03-06T14:43:57+08:00 authentication,signing kubelet-bootstrap-token system:bootstrappers:k8s-03
token有效期为1天，超期后将不能被用来bootstrap kubelet，且会被kube-controller-manager的token cleaner清理
kube-apiserver接收kubelet的bootstrap token后，将请求的user设置为system:bootstrap; group设置为system:bootstrappers，后续将为这个group设置ClusterRoleBinding
查看各token关联的Secret
kubectl get secrets -n kube-system|grep bootstrap-token
bootstrap-token-arc548 bootstrap.kubernetes.io/token 7 5m30s
bootstrap-token-eg8wj5 bootstrap.kubernetes.io/token 7 5m30s
bootstrap-token-k555eq bootstrap.kubernetes.io/token 7 5m31s
bootstrap-token-zfcoqb bootstrap.kubernetes.io/token 7 5m30s
分发 bootstrap kubeconfig 文件到所有 worker 节点
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
scp kubelet-bootstrap-${node_name}.kubeconfig root@${node_name}:/etc/kubernetes/kubelet-bootstrap.kubeconfig
done
创建和分发kubelet参数配置
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > kubelet-config.yaml.template <<EOF
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: "##NODE_IP##"
staticPodPath: ""
syncFrequency: 1m
fileCheckFrequency: 20s
httpCheckFrequency: 20s
staticPodURL: ""
port: 10250
readOnlyPort: 0
rotateCertificates: true
serverTLSBootstrap: true
authentication:
anonymous:
enabled: false
webhook:
enabled: true
x509:
clientCAFile: "/etc/kubernetes/cert/ca.pem"
authorization:
mode: Webhook
registryPullQPS: 0
registryBurst: 20
eventRecordQPS: 0
eventBurst: 20
enableDebuggingHandlers: true
enableContentionProfiling: true
healthzPort: 10248
healthzBindAddress: "##NODE_IP##"
clusterDomain: "${CLUSTER_DNS_DOMAIN}"
clusterDNS:
- "${CLUSTER_DNS_SVC_IP}"
nodeStatusUpdateFrequency: 10s
nodeStatusReportFrequency: 1m
imageMinimumGCAge: 2m
imageGCHighThresholdPercent: 85
imageGCLowThresholdPercent: 80
volumeStatsAggPeriod: 1m
kubeletCgroups: ""
systemCgroups: ""
cgroupRoot: ""
cgroupsPerQOS: true
cgroupDriver: systemd
runtimeRequestTimeout: 10m
hairpinMode: promiscuous-bridge
maxPods: 220
podCIDR: "${CLUSTER_CIDR}"
podPidsLimit: -1
resolvConf: /etc/resolv.conf
maxOpenFiles: 1000000
kubeAPIQPS: 1000
kubeAPIBurst: 2000
serializeImagePulls: false
evictionHard:
memory.available: "100Mi"
nodefs.available: "10%"
nodefs.inodesFree: "5%"
imagefs.available: "15%"
evictionSoft: {}
enableControllerAttachDetach: true
failSwapOn: true
containerLogMaxSize: 20Mi
containerLogMaxFiles: 10
systemReserved: {}
kubeReserved: {}
systemReservedCgroup: ""
kubeReservedCgroup: ""
enforceNodeAllocatable: ["pods"]
EOF
为各个节点创建和分发kubelet配置文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
sed -e "s/##NODE_IP##/${node_ip}/" kubelet-config.yaml.template > kubelet-config-${node_ip}.yaml.template
scp kubelet-config-${node_ip}.yaml.template root@${node_ip}:/etc/kubernetes/kubelet-config.yaml
done
创建和分发kubelet启动文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > kubelet.service.template <<EOF
[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=docker.service
Requires=docker.service
[Service]
WorkingDirectory=${K8S_DIR}/kubelet
ExecStart=/opt/k8s/bin/kubelet \
--allow-privileged=true \
--bootstrap-kubeconfig=/etc/kubernetes/kubelet-bootstrap.kubeconfig \
--cert-dir=/etc/kubernetes/cert \
--cni-conf-dir=/etc/cni/net.d \
--container-runtime=docker \
--container-runtime-endpoint=unix:///var/run/dockershim.sock \
--root-dir=${K8S_DIR}/kubelet \
--kubeconfig=/etc/kubernetes/kubelet.kubeconfig \
--config=/etc/kubernetes/kubelet-config.yaml \
--hostname-override=##NODE_NAME## \
--pod-infra-container-image=gcr.azk8s.cn/google_containers/pause-amd64:3.1 \
--image-pull-progress-deadline=15m \
--volume-plugin-dir=${K8S_DIR}/kubelet/kubelet-plugins/volume/exec/ \
--logtostderr=true \
--v=2
Restart=always
RestartSec=5
StartLimitInterval=0
[Install]
WantedBy=multi-user.target
EOF
分发启动文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
sed -e "s/##NODE_NAME##/${node_name}/" kubelet.service.template > kubelet-${node_name}.service
scp kubelet-${node_name}.service root@${node_name}:/etc/systemd/system/kubelet.service
done
Bootstrap Token Auth 和授予权限 kubelet 启动时查找 --kubeletconfig
参数对应的文件是否存在，如果不存在则使用 --bootstrap-kubeconfig 指定的 kubeconfig 文件向
kube-apiserver 发送证书签名请求 (CSR)。 kube-apiserver 收到 CSR 请求后，对其中的 Token
进行认证，认证通过后将请求的 user 设置为 system:bootstrap:，group 设置为
system:bootstrappers，这一过程称为 Bootstrap Token Auth。
创建user和group的CSR权限，不创建kubelet会启动失败
kubectl create clusterrolebinding kubelet-bootstrap --clusterrole=system:node-bootstrapper --group=system:bootstrappers
启动 kubelet 服务
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p ${K8S_DIR}/kubelet/kubelet-plugins/volume/exec/"
ssh root@${node_ip} "/usr/sbin/swapoff -a"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kubelet && systemctl restart kubelet"
done
关闭 swap 分区，否则 kubelet 会启动失败；
kubelet 启动后使用 –bootstrap-kubeconfig 向 kube-apiserver 发送 CSR 请求，当这个
CSR 被 approve 后，kube-controller-manager 为 kubelet 创建 TLS 客户端证书、私钥和
–kubeletconfig 文件。 注意：kube-controller-manager 需要配置 –cluster-signing-cert-file 和 –cluster-signing-key-file 参数，才会为 TLS Bootstrap 创建证书和私钥。
kubectl get csr
然后会发现好多pending (正在加载中)
自动approve CSR请求
创建三个ClusterRoleBinding，分别用于自动approve client、renew client、renew server证书
cd /opt/k8s/work
cat > csr-crb.yaml <<EOF
# Approve all CSRs for the group "system:bootstrappers"
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: auto-approve-csrs-for-group
subjects:
- kind: Group
name: system:bootstrappers
apiGroup: rbac.authorization.k8s.io
roleRef:
kind: ClusterRole
name: system:certificates.k8s.io:certificatesigningrequests:nodeclient
apiGroup: rbac.authorization.k8s.io
---
# To let a node of the group "system:nodes" renew its own credentials
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: node-client-cert-renewal
subjects:
- kind: Group
name: system:nodes
apiGroup: rbac.authorization.k8s.io
roleRef:
kind: ClusterRole
name: system:certificates.k8s.io:certificatesigningrequests:selfnodeclient
apiGroup: rbac.authorization.k8s.io
---
# A ClusterRole which instructs the CSR approver to approve a node requesting a
# serving cert matching its client cert.
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: approve-node-server-renewal-csr
rules:
- apiGroups: ["certificates.k8s.io"]
resources: ["certificatesigningrequests/selfnodeserver"]
verbs: ["create"]
---
# To let a node of the group "system:nodes" renew its own server credentials
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: node-server-cert-renewal
subjects:
- kind: Group
name: system:nodes
apiGroup: rbac.authorization.k8s.io
roleRef:
kind: ClusterRole
name: approve-node-server-renewal-csr
apiGroup: rbac.authorization.k8s.io
EOF
kubectl apply -f csr-crb.yaml
查看kubelet
等待1-10分钟，3个节点的CSR都会自动approved
kubectl get csr
kubectl get csr | head -10
NAME AGE REQUESTOR CONDITION
csr-24frb 40m system:bootstrap:zfcoqb Approved,Issued
csr-24rtq 63m system:bootstrap:zfcoqb Approved,Issued
csr-25m98 74m system:bootstrap:k555eq Approved,Issued
csr-26c64 58m system:bootstrap:k555eq Approved,Issued
csr-26wbs 50m system:bootstrap:arc548 Approved,Issued
csr-27fp4 34m system:bootstrap:eg8wj5 Approved,Issued
csr-28pgw 59m system:bootstrap:eg8wj5 Approved,Issued
csr-2bq87 57m system:bootstrap:arc548 Approved,Issued
csr-2cvlq 36m system:bootstrap:arc548 Approved,Issued
Pending的CSR用于创建kubelet serve证书，需要手动approve (后面步骤)
目前所有节点均为ready状态
[root@abcdocker-k8s01 work]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-01 Ready 2m29s v1.14.2
k8s-02 Ready 2m28s v1.14.2
k8s-03 Ready 2m28s v1.14.2
k8s-04 Ready 2m27s v1.14.2
因出现kubectl get node No resources found. ###需要重新分析步骤,到这里停止
查看报错
3月 05 18:27:08 k8s-01 kubelet[124075]: F0305 18:27:08.503116 124075 server.go:265] failed to run Kubelet: failed to create kubelet: misconfiguration: kubelet cgroup driver: "systemd" is different from docker cgroup driver: "cgroupfs"
mkdir -p /etc/docker
cat > /etc/docker/daemon.json << EOF
{
"exec-opts": ["native.cgroupdriver=systemd"],
"registry-mirrors": ["https://hjvrgh7a.mirror.aliyuncs.com"],
"log-driver": "json-file",
"log-opts": {
"max-size": "100m"
},
"storage-driver": "overlay2"
}
EOF
systemctl daemon-reload #加载配置文件
systemctl restart docker #重启docker
systemctl restart kubelet #重启kubelet
systemctl status kubelet #查看kubelet状态
手动approve server cert csr
基于安全考虑，CSR approving controllers不会自动approve kubelet server证书签名请求，需要手动approve
kubectl get csr | grep Pending | awk '{print $1}' | xargs kubectl certificate approve
kubectl get csr | grep Pending | awk '{print $1}' | xargs kubectl certificate approve
certificatesigningrequest.certificates.k8s.io/csr-ltf7g approved
certificatesigningrequest.certificates.k8s.io/csr-p7ltq approved
certificatesigningrequest.certificates.k8s.io/csr-pvf82 approved
certificatesigningrequest.certificates.k8s.io/csr-pw56z approved
certificatesigningrequest.certificates.k8s.io/csr-srwvr approved
certificatesigningrequest.certificates.k8s.io/csr-w6r7c approved
certificatesigningrequest.certificates.k8s.io/csr-whbzb approved
certificatesigningrequest.certificates.k8s.io/csr-x75r4 approved
kubelet API接口
kubelet启动后监听多个端口，用于接受kube-apiserver或其他客户端发送的请求
netstat -lntup|grep kubelet
tcp 0 0 127.0.0.1:38716 0.0.0.0:* LISTEN 20260/kubelet
tcp 0 0 192.168.191.10:10248 0.0.0.0:* LISTEN 20260/kubelet
tcp 0 0 192.168.191.10:10250 0.0.0.0:* LISTEN 20260/kubelet
bear token认证和授权
创建一个ServiceAccount，将它和ClusterRole system:kubelet-api-admin绑定，从而具有调用kubelet API的权限
kubectl create sa kubelet-api-test
kubectl create clusterrolebinding kubelet-api-test --clusterrole=system:kubelet-api-admin --serviceaccount=default:kubelet-api-test
SECRET=$(kubectl get secrets | grep kubelet-api-test | awk '{print $1}')
TOKEN=$(kubectl describe secret ${SECRET} | grep -E '^token' | awk '{print $2}')
echo ${TOKEN}
部署kube-proxy组件
kube-proxy运行在所有worker节点上，它监听apiserver中service和endpoint的变化情况，创建路由规则提供服务IP和负载均衡功能。这里使用ipvs模式的kube-proxy进行部署
在各个节点需要安装ipvsadm和ipset命令，加载ip_vs内核模块
创建kube-proxy证书签名请求
cd /opt/k8s/work
cat > kube-proxy-csr.json <<EOF
{
"CN": "system:kube-proxy",
"key": {
"algo": "rsa",
"size": 2048
},
"names": [
{
"C": "CN",
"ST": "BeiJing",
"L": "BeiJing",
"O": "k8s",
"OU": "4Paradigm"
}
]
}
EOF
CN：指定该证书的 User 为 system:kube-proxy；
预定义的 RoleBinding system:node-proxier 将User system:kube-proxy 与 Role system:node-proxier 绑定，该 Role 授予了调用 kube-apiserver Proxy 相关 API 的权限；
该证书只会被 kube-proxy 当做 client 证书使用，所以 hosts 字段为空；
生成证书和私钥：
cd /opt/k8s/work
cfssl gencert -ca=/opt/k8s/work/ca.pem
-ca-key=/opt/k8s/work/ca-key.pem
-config=/opt/k8s/work/ca-config.json
-profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
ls kube-proxy*
创建和分发 kubeconfig 文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
kubectl config set-cluster kubernetes
--certificate-authority=/opt/k8s/work/ca.pem
--embed-certs=true
--server=${KUBE_APISERVER}
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-credentials kube-proxy
--client-certificate=kube-proxy.pem
--client-key=kube-proxy-key.pem
--embed-certs=true
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-context default
--cluster=kubernetes
--user=kube-proxy
--kubeconfig=kube-proxy.kubeconfig
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
–embed-certs=true：将 ca.pem 和 admin.pem 证书内容嵌入到生成的kubectl-proxy.kubeconfig文件中(不加时，写入的是证书文件路径)；
分发 kubeconfig 文件：
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
scp kube-proxy.kubeconfig root@${node_name}:/etc/kubernetes/
done
创建kube-proxy配置文件
从v1.10开始，kube-proxy部分参数可以配置在文件中，可以使用–write-config-to选项生成该配置文件
cd /opt/k8s/work
cat > kube-proxy-config.yaml.template <<EOF
kind: KubeProxyConfiguration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
clientConnection:
burst: 200
kubeconfig: "/etc/kubernetes/kube-proxy.kubeconfig"
qps: 100
bindAddress: ##NODE_IP##
healthzBindAddress: ##NODE_IP##:10256
metricsBindAddress: ##NODE_IP##:10249
enableProfiling: true
clusterCIDR: ${CLUSTER_CIDR}
hostnameOverride: ##NODE_NAME##
mode: "ipvs"
portRange: ""
kubeProxyIPTablesConfiguration:
masqueradeAll: false
kubeProxyIPVSConfiguration:
scheduler: rr
excludeCIDRs: []
EOF
分发和创建kube-proxy配置文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for (( i=0; i < 4; i++ ))
do
echo ">>> ${NODE_NAMES[i]}"
sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-proxy-config.yaml.template > kube-proxy-config-${NODE_NAMES[i]}.yaml.template
scp kube-proxy-config-${NODE_NAMES[i]}.yaml.template root@${NODE_NAMES[i]}:/etc/kubernetes/kube-proxy-config.yaml
done
#我这里一共有4个节点要运行，所以这里写4，这是整个集群的node节点的数量！ 这里一定要注意修改！
创建和分发 kube-proxy systemd unit 文件
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > kube-proxy.service <<EOF
[Unit]
Description=Kubernetes Kube-Proxy Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
[Service]
WorkingDirectory=${K8S_DIR}/kube-proxy
ExecStart=/opt/k8s/bin/kube-proxy \
--config=/etc/kubernetes/kube-proxy-config.yaml \
--logtostderr=true \
--v=2
Restart=on-failure
RestartSec=5
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF
分发 kube-proxy systemd unit 文件：
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_name in ${NODE_NAMES[@]}
do
echo ">>> ${node_name}"
scp kube-proxy.service root@${node_name}:/etc/systemd/system/
done
启动 kube-proxy 服务
cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "mkdir -p ${K8S_DIR}/kube-proxy"
ssh root@${node_ip} "modprobe ip_vs_rr"
ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-proxy && systemctl restart kube-proxy"
done
检查启动结果
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "systemctl status kube-proxy|grep Active"
done
检查监听端口
[root@abcdocker-k8s01 work]# netstat -lnpt|grep kube-prox
tcp 0 0 192.168.0.50:10249 0.0.0.0:* LISTEN 55015/kube-proxy
tcp 0 0 192.168.0.50:10256 0.0.0.0:* LISTEN 55015/kube-proxy
查看ipvs路由规则
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh root@${node_ip} "/usr/sbin/ipvsadm -ln"
done
验证集群功能
现在使用daemonset验证master和worker节点是否正常
[root@abcdocker-k8s01 work]# kubectl get node
NAME STATUS ROLES AGE VERSION
k8s-01 Ready 20m v1.14.2
k8s-02 Ready 20m v1.14.2
k8s-03 Ready 20m v1.14.2
k8s-04 Ready 20m v1.14.2
创建测试yaml文件
cd /opt/k8s/work
cat > nginx-ds.yml <<EOF
apiVersion: v1
kind: Service
metadata:
name: nginx-ds
labels:
app: nginx-ds
spec:
type: NodePort
selector:
app: nginx-ds
ports:
- name: http
port: 80
targetPort: 80
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
name: nginx-ds
labels:
addonmanager.kubernetes.io/mode: Reconcile
spec:
template:
metadata:
labels:
app: nginx-ds
spec:
containers:
- name: my-nginx
image: daocloud.io/library/nginx:1.13.0-alpine
ports:
- containerPort: 80
EOF
执行测试
kubectl create -f nginx-ds.yml
这里pod已经启动成功
kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-ds-7hdb6 1/1 Running 0 39s 172.30.112.2 k8s-04 <none> <none>
nginx-ds-7vssv 1/1 Running 0 39s 172.30.56.2 k8s-03 <none> <none>
nginx-ds-dn6ms 1/1 Running 0 39s 172.30.48.2 k8s-01 <none> <none>
nginx-ds-jmwqq 1/1 Running 0 39s 172.30.232.2 k8s-02 <none> <none>
检查各节点的Pod IP 连通性
这里看到pod的IP，我们将ip复制一下
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh ${node_ip} "ping -c 1 172.30.112.2"
ssh ${node_ip} "ping -c 1 172.30.56.2"
ssh ${node_ip} "ping -c 1 172.30.48.2"
done
检查服务IP和端口可达性
kubectl get svc |grep nginx-ds
nginx-ds NodePort 10.254.43.214 <none> 80:12717/TCP 6m36s
我们在任意节点访问server IP
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo ">>> ${node_ip}"
ssh ${node_ip} "curl -s 10.254.43.214"
done
#这里请根据上面查看的svc IP进行修改
访问方式
此时我们已经可以使用任意节点IP+15402端口访问nginx (这个端口是通过kubectl get svc获取到的，每个人的端口可能不一样。请按照实际情况进行修改！)
http://192.168.191.10:12717/ ## 比如这个 用的本机的ip+查出来的端口
CoreDNS安装
上面我们验证的集群内部网络，已经没有问题。接下来进行安装DNS
这里的所有操作在k8s01上执行即可
source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
do
echo "$node_ip"
ssh $node_ip "wget -P /opt/ http://down.i4t.com/coredns_v1.4.tar"
ssh $node_ip "docker load -i /opt/coredns_v1.4.tar"
done
#下载镜像并分发镜像
下载coredns yaml文件
wget -P /opt/ http://down.i4t.com/k8s1.14/coredns.yaml
创建coredns
kubectl create -f /opt/coredns.yaml
#这里已经镜像让你们手动下载了，没有下载请看docker步骤,最后一步
执行完毕后，pod启动成功 (Running状态为正常)
kubectl get pod -n kube-system -l k8s-app=kube-dns
NAME READY STATUS RESTARTS AGE
coredns-6776c9d69-mxpvr 1/1 Running 0 21s
coredns-6776c9d69-rpf7t 1/1 Running 0 21s
coredns启动之后，我们需要测一下dns功能是否正常
温馨提示：busybox高版本有nslookup Bug，不建议使用高版本，请按照我的版本进行操作即可！
创建一个yaml文件测试是否正常
cat<<EOF | kubectl apply -f -
apiVersion: v1
kind: Pod
metadata:
name: busybox
namespace: default
spec:
containers:
- name: busybox
image: busybox:1.28.3
command:
- sleep
- "3600"
imagePullPolicy: IfNotPresent
restartPolicy: Always
EOF
创建后Pod我们进行检查
kubectl get pod
NAME READY STATUS RESTARTS AGE
busybox 1/1 Running 0 4s
使用nslookup查看是否能返回地址
kubectl exec -ti busybox -- nslookup kubernetes
Server: 10.254.0.2
Address 1: 10.254.0.2 kube-dns.kube-system.svc.cluster.local
Name: kubernetes
Address 1: 10.254.0.1 kubernetes.default.svc.cluster.local