kubernetes 1.20版本 二进制部署

kubernetes 1.20版本 二进制部署

目录

• kubernetes 1.20版本 二进制部署
• 1. 前言
• 2. 环境准备
  • 2.1 机器规划
  • 2.2 软件版本
• 3. 搭建集群
  • 3.1 机器基本配置
    • 3.1.1 修改主机名
    • 3.1.2 配置hosts文件
    • 3.1.3 关闭防火墙和selinux
    • 3.1.4 关闭交换分区
    • 3.1.5 时间同步
    • 3.1.6 修改内核参数
    • 3.1.7 加载ipvs模块
  • 3.2 配置工作目录
  • 3.3 搭建etcd集群
    • 3.3.1 配置etcd工作目录
    • 3.3.2 创建etcd证书
    • 3.3.3 部署etcd集群
  • 3.4 kubernetes组件部署
    • 3.4.1 下载安装包
    • 3.4.2 创建工作目录
    • 3.4.3 部署api-server
    • 3.4.4 部署kubectl
    • 3.4.5 部署kube-controller-manager
    • 3.4.6 部署kube-scheduler
    • 3.4.7 部署docker
    • 3.4.8 部署kubelet
    • 3.4.9 部署kube-proxy
    • 3.4.10 配置网络组件
    • 3.4.11 部署coredns
  • 3.5 验证
    • 3.5.1 部署nginx
    • 3.5.2 验证
    • 3.5.3 验证dns

1. 前言

之前文章安装 kubernetes 集群，都是使用 kubeadm 安装，然鹅很多公司也采用二进制方式搭建集群。这篇文章主要讲解，如何采用二进制包来搭建完整的高可用集群。相比使用 kubeadm 搭建，二进制搭建要繁琐很多，需要自己配置签名证书，每个组件都需要一步步配置安装。

2. 环境准备

2.1 机器规划

IP地址	机器名称	机器配置	操作系统	机器角色	安装软件
172.10.1.11	master01	2C4G	CentOS7.6	master	kube-apiserver、kube-controller-manager、kube-scheduler、etcd
172.10.1.12	master02	2C4G	CentOS7.6	master	kube-apiserver、kube-controller-manager、kube-scheduler、etcd
172.10.1.13	master03	2C4G	CentOS7.6	master	kube-apiserver、kube-controller-manager、kube-scheduler、etcd
172.10.1.14	node01	2C4G	CentOS7.6	worker	kubelet、kube-proxy
172.10.1.15	node02	2C4G	CentOS7.6	worker	kubelet、kube-proxy
172.10.1.16	node03	2C4G	CentOS7.6	worker	kubelet、kube-proxy
172.10.0.20	/	/	/	负载均衡VIP	/

注：此处VIP是采用的云厂商的SLB，你也可以使用haproxy + keepalived的方式实现。

2.2 软件版本

软件	版本
kube-apiserver、kube-controller-manager、kube-scheduler、kubelet、kube-proxy	v1.20.2
kube-apiserver、kube-controller-manager、kube-scheduler、kubelet、kube-proxy	v1.20.2
etcd	v3.4.13
calico	v3.14
coredns	1.7.0

3. 搭建集群

3.1 机器基本配置

以下配置在6台机器上面操作

3.1.1 修改主机名

修改主机名称：master01、master02、master03、node01、node02、node03

3.1.2 配置hosts文件

修改机器的/etc/hosts文件

cat >> /etc/hosts << EOF
172.10.1.11 master01
172.10.1.12 master02
172.10.1.13 master03
172.10.1.14 node01
172.10.1.15 node02
172.10.1.16 node03
EOF

hostnamectl set-hostname node02
bash

3.1.3 关闭防火墙和selinux

systemctl stop firewalld
setenforce 0
sed -i 's/^SELINUX=.\*/SELINUX=disabled/' /etc/selinux/config

3.1.4 关闭交换分区

swapoff -a
永久关闭，修改/etc/fstab,注释掉swap一行

3.1.5 时间同步

yum install -y chrony
systemctl start chronyd
systemctl enable chronyd
chronyc sources

3.1.6 修改内核参数

cat > /etc/sysctl.d/k8s.conf << EOF
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system

3.1.7 加载ipvs模块

modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
lsmod | grep ip_vs
lsmod | grep nf_conntrack_ipv4
yum install -y ipvsadm

3.2 配置工作目录

每台机器都需要配置证书文件、组件的配置文件、组件的服务启动文件，现专门选择 master01 来统一生成这些文件，然后再分发到其他机器。以下操作在 master01 上进行

[root@master01 ~]# mkdir -p /data/work
注：该目录为配置文件和证书文件生成目录，后面的所有文件生成相关操作均在此目录下进行
[root@master01 ~]# ssh-keygen -t rsa -b 2048
将秘钥分发到另外五台机器，让 master01 可以免密码登录其他机器

3.3 搭建etcd集群

3.3.1 配置etcd工作目录

[root@master01 ~]# mkdir -p /etc/etcd                     # 配置文件存放目录
[root@master01 ~]# mkdir -p /etc/etcd/ssl               # 证书文件存放目录

3.3.2 创建etcd证书

工具下载

[root@master01 work]# cd /data/work/
[root@master01 work]# wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
[root@master01 work]# wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
[root@master01 work]# wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64

工具配置

[root@master01 work]# chmod +x cfssl*
[root@master01 work]# mv cfssl_linux-amd64 /usr/local/bin/cfssl
[root@master01 work]# mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
[root@master01 work]# mv cfssl-certinfo_linux-amd64 /usr/local/bin/cfssl-certinfo

配置ca请求文件

[root@master01 work]# vim ca-csr.json
{
  "CN": "kubernetes",
  "key": {
      "algo": "rsa",
      "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "system"
    }
  ],
  "ca": {
          "expiry": "87600h"
  }
}

注：

CN：Common Name，kube-apiserver 从证书中提取该字段作为请求的用户名 (User Name)；浏览器使用该字段验证网站是否合法；

O：Organization，kube-apiserver 从证书中提取该字段作为请求用户所属的组 (Group)

创建ca证书

[root@master01 work]# cfssl gencert -initca ca-csr.json  | cfssljson -bare ca

配置ca证书策略

[root@master01 work]# vim ca-config.json
{
  "signing": {
      "default": {
          "expiry": "87600h"
        },
      "profiles": {
          "kubernetes": {
              "usages": [
                  "signing",
                  "key encipherment",
                  "server auth",
                  "client auth"
              ],
              "expiry": "87600h"
          }
      }
  }
}

配置etcd请求csr文件

[root@master01 work]# vim etcd-csr.json
{
  "CN": "etcd",
  "hosts": [
    "127.0.0.1",
    "172.10.1.11",
    "172.10.1.12",
    "172.10.1.13"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [{
    "C": "CN",
    "ST": "BeiJing",
    "L": "BeiJing",
    "O": "k8s",
    "OU": "system"
  }]
}

#注意：这里要写所有的etcd节点

生成证书

[root@master01 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes etcd-csr.json|cfssljson -bare etcd
[root@master01 work]# ls etcd*.pem
etcd-key.pem  etcd.pem

3.3.3 部署etcd集群

下载etcd软件包

[root@master01 work]# wget https://github.com/etcd-io/etcd/releases/download/v3.4.13/etcd-v3.4.13-linux-amd64.tar.gz
[root@master01 work]# tar -xf etcd-v3.4.13-linux-amd64.tar.gz
[root@master01 work]# cp -p etcd-v3.4.13-linux-amd64/etcd* /usr/local/bin/
[root@master01 work]# rsync -vaz etcd-v3.4.13-linux-amd64/etcd* master02:/usr/local/bin/
[root@master01 work]# rsync -vaz etcd-v3.4.13-linux-amd64/etcd* master03:/usr/local/bin/

创建配置文件

[root@master01 work]# vim etcd.conf
#[Member]
ETCD_NAME="etcd1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://172.10.1.11:2380"
ETCD_LISTEN_CLIENT_URLS="https://172.10.1.11:2379,http://127.0.0.1:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.10.1.11:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://172.10.1.11:2379"
ETCD_INITIAL_CLUSTER="etcd1=https://172.10.1.11:2380,etcd2=https://172.10.1.12:2380,etcd3=https://172.10.1.13:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

注：

ETCD_NAME：节点名称，集群中唯一

ETCD_DATA_DIR：数据目录

ETCD_LISTEN_PEER_URLS：集群通信监听地址

ETCD_LISTEN_CLIENT_URLS：客户端访问监听地址

ETCD_INITIAL_ADVERTISE_PEER_URLS：集群通告地址

ETCD_ADVERTISE_CLIENT_URLS：客户端通告地址

ETCD_INITIAL_CLUSTER：集群节点地址

ETCD_INITIAL_CLUSTER_TOKEN：集群Token

ETCD_INITIAL_CLUSTER_STATE：加入集群的当前状态，new是新集群，existing表示加入已有集群

创建启动服务文件

方式一：

有配置文件的启动

[root@master01 work]# vim etcd.service
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
EnvironmentFile=-/etc/etcd/etcd.conf
WorkingDirectory=/var/lib/etcd/
ExecStart=/usr/local/bin/etcd \
  --cert-file=/etc/etcd/ssl/etcd.pem \
  --key-file=/etc/etcd/ssl/etcd-key.pem \
  --trusted-ca-file=/etc/etcd/ssl/ca.pem \
  --peer-cert-file=/etc/etcd/ssl/etcd.pem \
  --peer-key-file=/etc/etcd/ssl/etcd-key.pem \
  --peer-trusted-ca-file=/etc/etcd/ssl/ca.pem \
  --peer-client-cert-auth \
  --client-cert-auth
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

方式二：

无配置文件的启动方式

[root@master01 work]# vim etcd.service
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
WorkingDirectory=/var/lib/etcd/
ExecStart=/usr/local/bin/etcd \
  --name=etcd1 \
  --data-dir=/var/lib/etcd/default.etcd \
  --cert-file=/etc/etcd/ssl/etcd.pem \
  --key-file=/etc/etcd/ssl/etcd-key.pem \
  --trusted-ca-file=/etc/etcd/ssl/ca.pem \
  --peer-cert-file=/etc/etcd/ssl/etcd.pem \
  --peer-key-file=/etc/etcd/ssl/etcd-key.pem \
  --peer-trusted-ca-file=/etc/etcd/ssl/ca.pem \
  --peer-client-cert-auth \
  --client-cert-auth \
  --listen-peer-urls=https://172.10.1.11:2380 \
  --listen-client-urls=https://172.10.1.11:2379,http://127.0.0.1:2379 \
  --advertise-client-urls=https://172.10.1.11:2379 \
  --initial-advertise-peer-urls=https://172.10.1.11:2380 \
  --initial-cluster=etcd1=https://172.10.1.11:2380,etcd2=https://172.10.1.12:2380,etcd3=https://172.10.1.13:2380 \
  --initial-cluster-token=etcd-cluster \
  --initial-cluster-state=new
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

注：本文采用第一种方式

同步相关文件到各个节点

[root@master01 work]# cp ca*.pem /etc/etcd/ssl/
[root@master01 work]# cp etcd*.pem /etc/etcd/ssl/
[root@master01 work]# cp etcd.conf /etc/etcd/
[root@master01 work]# cp etcd.service /usr/lib/systemd/system/
[root@master01 work]# for i in master02 master03;do rsync -vaz etcd.conf $i:/etc/etcd/;done
[root@master01 work]# for i in master02 master03;do rsync -vaz etcd*.pem ca*.pem $i:/etc/etcd/ssl/;done
[root@master01 work]# for i in master02 master03;do rsync -vaz etcd.service $i:/usr/lib/systemd/system/;done

注：master02和master03分别修改配置文件中etcd名字和ip，并创建目录 /var/lib/etcd/default.etcd

启动etcd集群

[root@master01 work]# mkdir -p /var/lib/etcd/default.etcd
[root@master01 work]# systemctl daemon-reload
[root@master01 work]# systemctl enable etcd.service
[root@master01 work]# systemctl start etcd.service
[root@master01 work]# systemctl status etcd

注：第一次启动可能会卡一段时间，因为节点会等待其他节点启动

查看集群状态

[root@master01 work]# ETCDCTL_API=3 /usr/local/bin/etcdctl --write-out=table --cacert=/etc/etcd/ssl/ca.pem --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem --endpoints=https://172.10.1.11:2379,https://172.10.1.12:2379,https://172.10.1.13:2379 endpoint health

3.4 kubernetes组件部署

3.4.1 下载安装包

[root@master01 work]# wget https://dl.k8s.io/v1.20.1/kubernetes-server-linux-amd64.tar.gz
[root@master01 work]# tar -xf kubernetes-server-linux-amd64.tar.gz
[root@master01 work]# cd kubernetes/server/bin/
[root@master01 bin]# cp kube-apiserver kube-controller-manager kube-scheduler kubectl /usr/local/bin/
[root@master01 bin]# rsync -vaz kube-apiserver kube-controller-manager kube-scheduler kubectl master02:/usr/local/bin/
[root@master01 bin]# rsync -vaz kube-apiserver kube-controller-manager kube-scheduler kubectl master03:/usr/local/bin/
[root@master01 bin]# for i in node01 node02 node03;do rsync -vaz kubelet kube-proxy $i:/usr/local/bin/;done
[root@master01 bin]# cd /data/work/

3.4.2 创建工作目录

[root@master01 work]# mkdir -p /etc/kubernetes/        # kubernetes组件配置文件存放目录
[root@master01 work]# mkdir -p /etc/kubernetes/ssl     # kubernetes组件证书文件存放目录
[root@master01 work]# mkdir /var/log/kubernetes        # kubernetes组件日志文件存放目录

3.4.3 部署api-server

创建csr请求文件

[root@master01 work]# vim kube-apiserver-csr.json
{
  "CN": "kubernetes",
  "hosts": [
    "127.0.0.1",
    "172.10.1.11",
    "172.10.1.12",
    "172.10.1.13",
    "172.10.1.14",
    "172.10.1.15",
    "172.10.1.16",
    "172.10.0.20",
    "10.255.0.1",
    "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"
    }
  ]
}

注：

如果 hosts 字段不为空则需要指定授权使用该证书的 IP 或域名列表。

由于该证书后续被 kubernetes master 集群使用，需要将master节点的IP都填上，同时还需要填写 service 网络的首个IP。(一般是 kube-apiserver 指定的 service-cluster-ip-range 网段的第一个IP，如 10.254.0.1)

生成证书和token文件

[root@master01 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-apiserver-csr.json | cfssljson -bare kube-apiserver
[root@master01 work]# cat > token.csv << EOF
$(head -c 16 /dev/urandom | od -An -t x | tr -d ' '),kubelet-bootstrap,10001,"system:kubelet-bootstrap"
EOF

创建配置文件

[root@master01 work]# vim kube-apiserver.conf
KUBE_APISERVER_OPTS="--enable-admission-plugins=NamespaceLifecycle,NodeRestriction,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota \
  --anonymous-auth=false \
  --bind-address=172.10.1.11 \
  --secure-port=6443 \
  --advertise-address=172.10.1.11 \
  --insecure-port=0 \
  --authorization-mode=Node,RBAC \
  --runtime-config=api/all=true \
  --enable-bootstrap-token-auth \
  --service-cluster-ip-range=10.255.0.0/16 \
  --token-auth-file=/etc/kubernetes/token.csv \
  --service-node-port-range=30000-50000 \
  --tls-cert-file=/etc/kubernetes/ssl/kube-apiserver.pem  \
  --tls-private-key-file=/etc/kubernetes/ssl/kube-apiserver-key.pem \
  --client-ca-file=/etc/kubernetes/ssl/ca.pem \
  --kubelet-client-certificate=/etc/kubernetes/ssl/kube-apiserver.pem \
  --kubelet-client-key=/etc/kubernetes/ssl/kube-apiserver-key.pem \
  --service-account-key-file=/etc/kubernetes/ssl/ca-key.pem \
	--service-account-signing-key-file=/etc/kubernetes/ssl/ca-key.pem  \      # 1.20以上版本必须有此参数
  --service-account-issuer=https://kubernetes.default.svc.cluster.local \   # 1.20以上版本必须有此参数
  --etcd-cafile=/etc/etcd/ssl/ca.pem \
  --etcd-certfile=/etc/etcd/ssl/etcd.pem \
  --etcd-keyfile=/etc/etcd/ssl/etcd-key.pem \
  --etcd-servers=https://172.10.1.11:2379,https://172.10.1.12:2379,https://172.10.1.13:2379 \
  --enable-swagger-ui=true \
  --allow-privileged=true \
  --apiserver-count=3 \
  --audit-log-maxage=30 \
  --audit-log-maxbackup=3 \
  --audit-log-maxsize=100 \
  --audit-log-path=/var/log/kube-apiserver-audit.log \
  --event-ttl=1h \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=4"

注：

--logtostderr：启用日志

--v：日志等级

--log-dir：日志目录

--etcd-servers：etcd集群地址

--bind-address：监听地址

--secure-port：https安全端口

--advertise-address：集群通告地址

--allow-privileged：启用授权

--service-cluster-ip-range：Service虚拟IP地址段

--enable-admission-plugins：准入控制模块

--authorization-mode：认证授权，启用RBAC授权和节点自管理

--enable-bootstrap-token-auth：启用TLS bootstrap机制

--token-auth-file：bootstrap token文件

--service-node-port-range：Service nodeport类型默认分配端口范围

--kubelet-client-xxx：apiserver访问kubelet客户端证书

--tls-xxx-file：apiserver https证书

--etcd-xxxfile：连接Etcd集群证书

--audit-log-xxx：审计日志

创建服务启动文件

[root@master01 work]# vim kube-apiserver.service
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes
After=etcd.service
Wants=etcd.service

[Service]
EnvironmentFile=-/etc/kubernetes/kube-apiserver.conf
ExecStart=/usr/local/bin/kube-apiserver $KUBE_APISERVER_OPTS
Restart=on-failure
RestartSec=5
Type=notify
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

同步相关文件到各个节点

[root@master01 work]# cp ca*.pem /etc/kubernetes/ssl/
[root@master01 work]# cp kube-apiserver*.pem /etc/kubernetes/ssl/
[root@master01 work]# cp token.csv /etc/kubernetes/
[root@master01 work]# cp kube-apiserver.conf /etc/kubernetes/
[root@master01 work]# cp kube-apiserver.service /usr/lib/systemd/system/
[root@master01 work]# rsync -vaz token.csv master02:/etc/kubernetes/
[root@master01 work]# rsync -vaz token.csv master03:/etc/kubernetes/
[root@master01 work]# rsync -vaz kube-apiserver*.pem master02:/etc/kubernetes/ssl/     # 主要rsync同步文件，只能创建最后一级目录，如果ssl目录不存在会自动创建，但是上一级目录kubernetes必须存在
[root@master01 work]# rsync -vaz kube-apiserver*.pem master03:/etc/kubernetes/ssl/
[root@master01 work]# rsync -vaz ca*.pem master02:/etc/kubernetes/ssl/
[root@master01 work]# rsync -vaz ca*.pem master03:/etc/kubernetes/ssl/
[root@master01 work]# rsync -vaz kube-apiserver.conf master02:/etc/kubernetes/
[root@master01 work]# rsync -vaz kube-apiserver.conf master03:/etc/kubernetes/
[root@master01 work]# rsync -vaz kube-apiserver.service master02:/usr/lib/systemd/system/
[root@master01 work]# rsync -vaz kube-apiserver.service master03:/usr/lib/systemd/system/

注：master02和master03配置文件的IP地址修改为实际的本机IP

启动服务

[root@master01 work]# systemctl daemon-reload
[root@master01 work]# systemctl enable kube-apiserver
[root@master01 work]# systemctl start kube-apiserver
[root@master01 work]# systemctl status kube-apiserver
测试
[root@master01 work]# curl --insecure https://172.10.1.11:6443/
有返回说明启动正常

3.4.4 部署kubectl

创建csr请求文件

[root@master01 work]# vim admin-csr.json
{
  "CN": "admin",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "system:masters",
      "OU": "system"
    }
  ]
}

说明：

后续 kube-apiserver 使用 RBAC 对客户端(如 kubelet、kube-proxy、Pod)请求进行授权；

kube-apiserver 预定义了一些 RBAC 使用的 RoleBindings，如 cluster-admin 将 Group system:masters 与 Role cluster-admin 绑定，该 Role 授予了调用kube-apiserver 的所有 API的权限；

O指定该证书的 Group 为 system:masters，kubelet 使用该证书访问 kube-apiserver 时 ，由于证书被 CA 签名，所以认证通过，同时由于证书用户组为经过预授权的 system:masters，所以被授予访问所有 API 的权限；

注：

这个admin 证书，是将来生成管理员用的kube config 配置文件用的，现在我们一般建议使用RBAC 来对kubernetes 进行角色权限控制， kubernetes 将证书中的CN 字段 作为User， O 字段作为 Group；

"O": "system:masters", 必须是system:masters，否则后面kubectl create clusterrolebinding报错。

生成证书

[root@master01 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin
[root@master01 work]# cp admin*.pem /etc/kubernetes/ssl/

创建kubeconfig配置文件

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

设置集群参数
[root@master01 work]# kubectl config set-cluster kubernetes --certificate-authority=ca.pem --embed-certs=true --server=https://172.10.0.20:6443 --kubeconfig=kube.config
设置客户端认证参数
[root@master01 work]# kubectl config set-credentials admin --client-certificate=admin.pem --client-key=admin-key.pem --embed-certs=true --kubeconfig=kube.config
设置上下文参数
[root@master01 work]# kubectl config set-context kubernetes --cluster=kubernetes --user=admin --kubeconfig=kube.config
设置默认上下文
[root@master01 work]# kubectl config use-context kubernetes --kubeconfig=kube.config
[root@master01 work]# mkdir ~/.kube
[root@master01 work]# cp kube.config ~/.kube/config
授权kubernetes证书访问kubelet api权限
[root@master01 work]# kubectl create clusterrolebinding kube-apiserver:kubelet-apis --clusterrole=system:kubelet-api-admin --user kubernetes

查看集群组件状态

上面步骤完成后，kubectl就可以与kube-apiserver通信了

[root@master01 work]# kubectl cluster-info
[root@master01 work]# kubectl get componentstatuses
[root@master01 work]# kubectl get all --all-namespaces

同步kubectl配置文件到其他节点

[root@master01 work]# rsync -vaz /root/.kube/config master02:/root/.kube/
[root@master01 work]# rsync -vaz /root/.kube/config master03:/root/.kube/

配置kubectl子命令补全

[root@master01 work]# yum install -y bash-completion
[root@master01 work]# source /usr/share/bash-completion/bash_completion
[root@master01 work]# source <(kubectl completion bash)
[root@master01 work]# kubectl completion bash > ~/.kube/completion.bash.inc
[root@master01 work]# source '/root/.kube/completion.bash.inc'
[root@master01 work]# source $HOME/.bash_profile

3.4.5 部署kube-controller-manager

创建csr请求文件

[root@master01 work]# vim kube-controller-manager-csr.json
{
    "CN": "system:kube-controller-manager",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "hosts": [
      "127.0.0.1",
      "172.10.1.11",
      "172.10.1.12",
      "172.10.1.13"
    ],
    "names": [
      {
        "C": "CN",
        "ST": "BeiJing",
        "L": "BeiJing",
        "O": "system:kube-controller-manager",
        "OU": "system"
      }
    ]
}

注：

hosts 列表包含所有 kube-controller-manager 节点 IP；

CN 为 system:kube-controller-manager、O 为 system:kube-controller-manager，kubernetes 内置的 ClusterRoleBindings system:kube-controller-manager 赋予 kube-controller-manager 工作所需的权限

生成证书

[root@master01 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager
[root@master01 work]# ls kube-controller-manager*.pem

创建kube-controller-manager的kubeconfig

设置集群参数
[root@master01 work]# kubectl config set-cluster kubernetes --certificate-authority=ca.pem --embed-certs=true --server=https://172.10.0.20:6443 --kubeconfig=kube-controller-manager.kubeconfig
设置客户端认证参数
[root@master01 work]# 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
设置上下文参数
[root@master01 work]# kubectl config set-context system:kube-controller-manager --cluster=kubernetes --user=system:kube-controller-manager --kubeconfig=kube-controller-manager.kubeconfig
设置默认上下文
[root@master01 work]# kubectl config use-context system:kube-controller-manager --kubeconfig=kube-controller-manager.kubeconfig

创建配置文件

[root@master01 work]# vim kube-controller-manager.conf
KUBE_CONTROLLER_MANAGER_OPTS="--port=0 \
  --secure-port=10252 \
  --bind-address=127.0.0.1 \
  --kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \
  --service-cluster-ip-range=10.255.0.0/16 \
  --cluster-name=kubernetes \
  --cluster-signing-cert-file=/etc/kubernetes/ssl/ca.pem \
  --cluster-signing-key-file=/etc/kubernetes/ssl/ca-key.pem \
  --allocate-node-cidrs=true \
  --cluster-cidr=10.0.0.0/16 \
  --experimental-cluster-signing-duration=87600h \
  --root-ca-file=/etc/kubernetes/ssl/ca.pem \
  --service-account-private-key-file=/etc/kubernetes/ssl/ca-key.pem \
  --leader-elect=true \
  --feature-gates=RotateKubeletServerCertificate=true \
  --controllers=*,bootstrapsigner,tokencleaner \
  --horizontal-pod-autoscaler-use-rest-clients=true \
  --horizontal-pod-autoscaler-sync-period=10s \
  --tls-cert-file=/etc/kubernetes/ssl/kube-controller-manager.pem \
  --tls-private-key-file=/etc/kubernetes/ssl/kube-controller-manager-key.pem \
  --use-service-account-credentials=true \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2"

创建启动文件

[root@master01 work]# vim kube-controller-manager.service
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/etc/kubernetes/kube-controller-manager.conf
ExecStart=/usr/local/bin/kube-controller-manager $KUBE_CONTROLLER_MANAGER_OPTS
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

同步相关文件到各个节点

[root@master01 work]# cp kube-controller-manager*.pem /etc/kubernetes/ssl/
[root@master01 work]# cp kube-controller-manager.kubeconfig /etc/kubernetes/
[root@master01 work]# cp kube-controller-manager.conf /etc/kubernetes/
[root@master01 work]# cp kube-controller-manager.service /usr/lib/systemd/system/
[root@master01 work]# rsync -vaz kube-controller-manager*.pem master02:/etc/kubernetes/ssl/
[root@master01 work]# rsync -vaz kube-controller-manager*.pem master03:/etc/kubernetes/ssl/
[root@master01 work]# rsync -vaz kube-controller-manager.kubeconfig kube-controller-manager.conf master02:/etc/kubernetes/
[root@master01 work]# rsync -vaz kube-controller-manager.kubeconfig kube-controller-manager.conf master03:/etc/kubernetes/
[root@master01 work]# rsync -vaz kube-controller-manager.service master02:/usr/lib/systemd/system/
[root@master01 work]# rsync -vaz kube-controller-manager.service master03:/usr/lib/systemd/system/

启动服务

[root@master01 work]# systemctl daemon-reload
[root@master01 work]# systemctl enable kube-controller-manager
[root@master01 work]# systemctl start kube-controller-manager
[root@master01 work]# systemctl status kube-controller-manager

3.4.6 部署kube-scheduler

创建csr请求文件

[root@master01 work]# vim kube-scheduler-csr.json
{
    "CN": "system:kube-scheduler",
    "hosts": [
      "127.0.0.1",
      "172.10.1.11",
      "172.10.1.12",
      "172.10.1.13"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
      {
        "C": "CN",
        "ST": "BeiJing",
        "L": "BeiJing",
        "O": "system:kube-scheduler",
        "OU": "system"
      }
    ]
}

注：

hosts 列表包含所有 kube-scheduler 节点 IP；

CN 为 system:kube-scheduler、O 为 system:kube-scheduler，kubernetes 内置的 ClusterRoleBindings system:kube-scheduler 将赋予 kube-scheduler 工作所需的权限。

生成证书

[root@master01 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-scheduler-csr.json | cfssljson -bare kube-scheduler
[root@master01 work]# ls kube-scheduler*.pem

创建kube-scheduler的kubeconfig

设置集群参数
[root@master01 work]# kubectl config set-cluster kubernetes --certificate-authority=ca.pem --embed-certs=true --server=https://172.10.0.20:6443 --kubeconfig=kube-scheduler.kubeconfig
设置客户端认证参数
[root@master01 work]# 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
设置上下文参数
[root@master01 work]# kubectl config set-context system:kube-scheduler --cluster=kubernetes --user=system:kube-scheduler --kubeconfig=kube-scheduler.kubeconfig
设置默认上下文
[root@master01 work]# kubectl config use-context system:kube-scheduler --kubeconfig=kube-scheduler.kubeconfig

创建配置文件

[root@master01 work]# vim kube-scheduler.conf
KUBE_SCHEDULER_OPTS="--address=127.0.0.1 \
--kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \
--leader-elect=true \
--alsologtostderr=true \
--logtostderr=false \
--log-dir=/var/log/kubernetes \
--v=2"

创建服务启动文件

[root@master01 work]# vim kube-scheduler.service
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes

[Service]
EnvironmentFile=-/etc/kubernetes/kube-scheduler.conf
ExecStart=/usr/local/bin/kube-scheduler $KUBE_SCHEDULER_OPTS
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

同步相关文件到各个节点

[root@master01 work]# cp kube-scheduler*.pem /etc/kubernetes/ssl/
[root@master01 work]# cp kube-scheduler.kubeconfig /etc/kubernetes/
[root@master01 work]# cp kube-scheduler.conf /etc/kubernetes/
[root@master01 work]# cp kube-scheduler.service /usr/lib/systemd/system/
[root@master01 work]# rsync -vaz kube-scheduler*.pem master02:/etc/kubernetes/ssl/
[root@master01 work]# rsync -vaz kube-scheduler*.pem master03:/etc/kubernetes/ssl/
[root@master01 work]# rsync -vaz kube-scheduler.kubeconfig kube-scheduler.conf master02:/etc/kubernetes/
[root@master01 work]# rsync -vaz kube-scheduler.kubeconfig kube-scheduler.conf master03:/etc/kubernetes/
[root@master01 work]# rsync -vaz kube-scheduler.service master02:/usr/lib/systemd/system/
[root@master01 work]# rsync -vaz kube-scheduler.service master03:/usr/lib/systemd/system/

启动服务

[root@master01 work]# systemctl daemon-reload
[root@master01 work]# systemctl enable kube-scheduler
[root@master01 work]# systemctl start kube-scheduler
[root@master01 work]# systemctl status kube-scheduler

3.4.7 部署docker

在三个work节点上安装

安装docker

[root@node01 ~]# wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
[root@node01 ~]# yum install -y docker-ce
[root@node01 ~]# systemctl enable docker
[root@node01 ~]# systemctl start docker
[root@node01 ~]# docker --version

修改docker源和驱动

[root@node01 ~]# cat > /etc/docker/daemon.json << EOF
{
    "exec-opts": ["native.cgroupdriver=systemd"],
    "registry-mirrors": [
        "https://1nj0zren.mirror.aliyuncs.com",
        "https://kfwkfulq.mirror.aliyuncs.com",
        "https://2lqq34jg.mirror.aliyuncs.com",
        "https://pee6w651.mirror.aliyuncs.com",
        "http://hub-mirror.c.163.com",
        "https://docker.mirrors.ustc.edu.cn",
        "http://f1361db2.m.daocloud.io",
        "https://registry.docker-cn.com"
    ]
}
EOF
[root@node01 ~]# systemctl restart docker
[root@node01 ~]# docker info | grep "Cgroup Driver"

下载依赖镜像

[root@node01 ~]# docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.2
[root@node01 ~]# docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.2 k8s.gcr.io/pause:3.2
[root@node01 ~]# docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.2

[root@node01 ~]# docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.7.0
[root@node01 ~]# docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.7.0 k8s.gcr.io/coredns:1.7.0
[root@node01 ~]# docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.7.0

3.4.8 部署kubelet

以下操作在master01上操作

创建kubelet-bootstrap.kubeconfig

[root@master01 work]# BOOTSTRAP_TOKEN=$(awk -F "," '{print $1}' /etc/kubernetes/token.csv)
设置集群参数
[root@master01 work]# kubectl config set-cluster kubernetes --certificate-authority=ca.pem --embed-certs=true --server=https://172.10.0.20:6443 --kubeconfig=kubelet-bootstrap.kubeconfig
设置客户端认证参数
[root@master01 work]# kubectl config set-credentials kubelet-bootstrap --token=${BOOTSTRAP_TOKEN} --kubeconfig=kubelet-bootstrap.kubeconfig
设置上下文参数
[root@master01 work]# kubectl config set-context default --cluster=kubernetes --user=kubelet-bootstrap --kubeconfig=kubelet-bootstrap.kubeconfig
设置默认上下文
[root@master01 work]# kubectl config use-context default --kubeconfig=kubelet-bootstrap.kubeconfig
创建角色绑定
[root@master01 work]# kubectl create clusterrolebinding kubelet-bootstrap --clusterrole=system:node-bootstrapper --user=kubelet-bootstrap

创建配置文件

[root@master01 work]#  vim kubelet.json
{
  "kind": "KubeletConfiguration",
  "apiVersion": "kubelet.config.k8s.io/v1beta1",
  "authentication": {
    "x509": {
      "clientCAFile": "/etc/kubernetes/ssl/ca.pem"
    },
    "webhook": {
      "enabled": true,
      "cacheTTL": "2m0s"
    },
    "anonymous": {
      "enabled": false
    }
  },
  "authorization": {
    "mode": "Webhook",
    "webhook": {
      "cacheAuthorizedTTL": "5m0s",
      "cacheUnauthorizedTTL": "30s"
    }
  },
  "address": "172.10.1.14",
  "port": 10250,
  "readOnlyPort": 10255,
  "cgroupDriver": "cgroupfs",                     # 如果docker的驱动为systemd，处修改为systemd。此处设置很重要，否则后面node节点无法加入到集群
  "hairpinMode": "promiscuous-bridge",
  "serializeImagePulls": false,
  "featureGates": {
    "RotateKubeletClientCertificate": true,
    "RotateKubeletServerCertificate": true
  },
  "clusterDomain": "cluster.local.",
  "clusterDNS": ["10.255.0.2"]
}

创建启动文件

[root@master01 work]# vim kubelet.service
[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/kubernetes/kubernetes
After=docker.service
Requires=docker.service

[Service]
WorkingDirectory=/var/lib/kubelet
ExecStart=/usr/local/bin/kubelet \
  --bootstrap-kubeconfig=/etc/kubernetes/kubelet-bootstrap.kubeconfig \
  --cert-dir=/etc/kubernetes/ssl \
  --kubeconfig=/etc/kubernetes/kubelet.kubeconfig \
  --config=/etc/kubernetes/kubelet.json \
  --network-plugin=cni \
  --pod-infra-container-image=k8s.gcr.io/pause:3.2 \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

注：

–hostname-override：显示名称，集群中唯一

–network-plugin：启用CNI

–kubeconfig：空路径，会自动生成，后面用于连接apiserver

–bootstrap-kubeconfig：首次启动向apiserver申请证书

–config：配置参数文件

–cert-dir：kubelet证书生成目录

–pod-infra-container-image：管理Pod网络容器的镜像

同步相关文件到各个节点

[root@master01 work]# cp kubelet-bootstrap.kubeconfig /etc/kubernetes/
[root@master01 work]# cp kubelet.json /etc/kubernetes/
[root@master01 work]# cp kubelet.service /usr/lib/systemd/system/
以上步骤，如果master节点不安装kubelet，则不用执行
[root@master01 work]# for i in node01 node02 node03;do rsync -vaz kubelet-bootstrap.kubeconfig kubelet.json $i:/etc/kubernetes/;done
[root@master01 work]# for i in node01 node02 node03;do rsync -vaz ca.pem $i:/etc/kubernetes/ssl/;done
[root@master01 work]# for i in node01 node02 node03;do rsync -vaz kubelet.service $i:/usr/lib/systemd/system/;done

注：kubelete.json配置文件address改为各个节点的ip地址

启动服务

各个work节点上操作

[root@node01 ~]# mkdir /var/lib/kubelet
[root@node01 ~]# mkdir /var/log/kubernetes
[root@node01 ~]# systemctl daemon-reload
[root@node01 ~]# systemctl enable kubelet
[root@node01 ~]# systemctl start kubelet
[root@node01 ~]# systemctl status kubelet

确认kubelet服务启动成功后，接着到master上Approve一下bootstrap请求。执行如下命令可以看到三个worker节点分别发送了三个 CSR 请求：

[root@master01 work]# kubectl get csr

[root@master01 work]# kubectl certificate approve node-csr-HlX3cExsZohWsu8Dd6Rp_ztFejmMdpzvti_qgxo4SAQ
[root@master01 work]# kubectl certificate approve node-csr-oykYfnH_coRF2PLJH4fOHlGznOZUBPDg5BPZXDo2wgk
[root@master01 work]# kubectl certificate approve node-csr-ytRB2fikhL6dykcekGg4BdD87o-zw9WPU44SZ1nFT50
[root@master01 work]# kubectl get csr
[root@master01 work]# kubectl get nodes

3.4.9 部署kube-proxy

创建csr请求文件

[root@master01 work]# vim kube-proxy-csr.json
{
  "CN": "system:kube-proxy",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "system"
    }
  ]
}

生成证书

[root@master01 work]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
[root@master01 work]# ls kube-proxy*.pem

创建kubeconfig文件

[root@master01 work]# kubectl config set-cluster kubernetes --certificate-authority=ca.pem --embed-certs=true --server=https://172.10.0.20:6443 --kubeconfig=kube-proxy.kubeconfig
[root@master01 work]# kubectl config set-credentials kube-proxy --client-certificate=kube-proxy.pem --client-key=kube-proxy-key.pem --embed-certs=true --kubeconfig=kube-proxy.kubeconfig
[root@master01 work]# kubectl config set-context default --cluster=kubernetes --user=kube-proxy --kubeconfig=kube-proxy.kubeconfig
[root@master01 work]# kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig

创建kube-proxy配置文件

[root@master01 work]# vim kube-proxy.yaml
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 172.10.1.14
clientConnection:
  kubeconfig: /etc/kubernetes/kube-proxy.kubeconfig
clusterCIDR: 192.168.0.0/16                           # 此处网段必须与网络组件网段保持一致，否则部署网络组件时会报错
healthzBindAddress: 172.10.1.14:10256
kind: KubeProxyConfiguration
metricsBindAddress: 172.10.1.14:10249
mode: "ipvs"

创建服务启动文件

[root@master01 work]# vim kube-proxy.service
[Unit]
Description=Kubernetes Kube-Proxy Server
Documentation=https://github.com/kubernetes/kubernetes
After=network.target

[Service]
WorkingDirectory=/var/lib/kube-proxy
ExecStart=/usr/local/bin/kube-proxy \
  --config=/etc/kubernetes/kube-proxy.yaml \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

同步文件到各个节点

[root@master01 work]# cp kube-proxy*.pem /etc/kubernetes/ssl/
[root@master01 work]# cp kube-proxy.kubeconfig kube-proxy.yaml /etc/kubernetes/
[root@master01 work]# cp kube-proxy.service /usr/lib/systemd/system/
master节点不安装kube-proxy，则以上步骤不用执行
[root@master01 work]# for i in node01 node02 node03;do rsync -vaz kube-proxy.kubeconfig kube-proxy.yaml $i:/etc/kubernetes/;done
[root@master01 work]# for i in node01 node02 node03;do rsync -vaz kube-proxy.service $i:/usr/lib/systemd/system/;done

注：配置文件kube-proxy.yaml中address修改为各节点的实际IP

启动服务

[root@node01 ~]# mkdir -p /var/lib/kube-proxy
[root@node01 ~]# systemctl daemon-reload
[root@node01 ~]# systemctl enable kube-proxy
[root@node01 ~]# systemctl restart kube-proxy
[root@node01 ~]# systemctl status kube-proxy

3.4.10 配置网络组件

[root@master01 work]# wget https://docs.projectcalico.org/v3.14/manifests/calico.yaml
[root@master01 work]# kubectl apply -f calico.yaml

此时再来查看各个节点，均为Ready状态

[root@master01 work]# kubectl get pods -A
[root@master01 work]# kubectl get nodes

3.4.11 部署coredns

下载coredns yaml文件：https://raw.githubusercontent.com/coredns/deployment/master/kubernetes/coredns.yaml.sed

修改yaml文件:

kubernetes cluster.local in-addr.arpa ip6.arpa

forward . /etc/resolv.conf

clusterIP为：10.255.0.2（kubelet配置文件中的clusterDNS）

[root@master01 work]# cat coredns.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: coredns
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:coredns
rules:
- apiGroups:
  - ""
  resources:
  - endpoints
  - services
  - pods
  - namespaces
  verbs:
  - list
  - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:coredns
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:coredns
subjects:
- kind: ServiceAccount
  name: coredns
  namespace: kube-system
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
data:
  Corefile: |
    .:53 {
        errors
        health {
          lameduck 5s
        }
        ready
        kubernetes cluster.local  in-addr.arpa ip6.arpa {
          fallthrough in-addr.arpa ip6.arpa
        }
        prometheus :9153
        forward . /etc/resolv.conf {
          max_concurrent 1000
        }
        cache 30
        loop
        reload
        loadbalance
    }
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: coredns
  namespace: kube-system
  labels:
    k8s-app: kube-dns
    kubernetes.io/name: "CoreDNS"
spec:
  # replicas: not specified here:
  # 1. Default is 1.
  # 2. Will be tuned in real time if DNS horizontal auto-scaling is turned on.
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 1
  selector:
    matchLabels:
      k8s-app: kube-dns
  template:
    metadata:
      labels:
        k8s-app: kube-dns
    spec:
      priorityClassName: system-cluster-critical
      serviceAccountName: coredns
      tolerations:
        - key: "CriticalAddonsOnly"
          operator: "Exists"
      nodeSelector:
        kubernetes.io/os: linux
      affinity:
         podAntiAffinity:
           preferredDuringSchedulingIgnoredDuringExecution:
           - weight: 100
             podAffinityTerm:
               labelSelector:
                 matchExpressions:
                   - key: k8s-app
                     operator: In
                     values: ["kube-dns"]
               topologyKey: kubernetes.io/hostname
      containers:
      - name: coredns
        image: coredns/coredns:1.8.0
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            memory: 170Mi
          requests:
            cpu: 100m
            memory: 70Mi
        args: [ "-conf", "/etc/coredns/Corefile" ]
        volumeMounts:
        - name: config-volume
          mountPath: /etc/coredns
          readOnly: true
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        - containerPort: 9153
          name: metrics
          protocol: TCP
        securityContext:
          allowPrivilegeEscalation: false
          capabilities:
            add:
            - NET_BIND_SERVICE
            drop:
            - all
          readOnlyRootFilesystem: true
        livenessProbe:
          httpGet:
            path: /health
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 60
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 5
        readinessProbe:
          httpGet:
            path: /ready
            port: 8181
            scheme: HTTP
      dnsPolicy: Default
      volumes:
        - name: config-volume
          configMap:
            name: coredns
            items:
            - key: Corefile
              path: Corefile
---
apiVersion: v1
kind: Service
metadata:
  name: kube-dns
  namespace: kube-system
  annotations:
    prometheus.io/port: "9153"
    prometheus.io/scrape: "true"
  labels:
    k8s-app: kube-dns
    kubernetes.io/cluster-service: "true"
    kubernetes.io/name: "CoreDNS"
spec:
  selector:
    k8s-app: kube-dns
  clusterIP: 10.255.0.2
  ports:
  - name: dns
    port: 53
    protocol: UDP
  - name: dns-tcp
    port: 53
    protocol: TCP
  - name: metrics
    port: 9153
    protocol: TCP
[root@master01 work]# kubectl apply -f coredns.yaml

3.5 验证

3.5.1 部署nginx

[root@master01 ~]# vim nginx.yaml
---
apiVersion: v1
kind: ReplicationController
metadata:
  name: nginx-controller
spec:
  replicas: 2
  selector:
    name: nginx
  template:
    metadata:
      labels:
        name: nginx
    spec:
      containers:
        - name: nginx
          image: nginx:1.19.6
          ports:
            - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-service-nodeport
spec:
  ports:
    - port: 80
      targetPort: 80
      nodePort: 30001
      protocol: TCP
  type: NodePort
  selector:
    name: nginx
[root@master01 ~]# kubectl apply -f nginx.yaml
[root@master01 ~]# kubectl get svc
[root@master01 ~]# kubectl get pods

3.5.2 验证

ping验证nginx service

访问nginx

3.5.3 验证dns

kubectl run -it --rm dns-test --image=busybox:1.28.4 sh

If you don't see a command prompt, try pressing enter. 

/ # nslookup kubernetes
Server:    10.0.0.2
Address 1: 10.0.0.2 kube-dns.kube-system.svc.cluster.local 

Name:      kubernetes
Address 1: 10.0.0.1 kubernetes.default.svc.cluster.local

[root@master1 work]# vim kube-apiserver-csr.json
{
  "CN": "kubernetes",
  "hosts": [
    "127.0.0.1",
    "192.168.5.100",
    "192.168.5.101",
    "192.168.5.102",
    "192.168.5.103",
    "10.255.0.1",
    "192.168.0.1",
    "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"
    }
  ]