Kubernetes集群部署—单Master架构部署（一）

文章目录

一、系统环境初始化
二、部署etcd集群
三、部署Master Node
四、部署Worker Node
五、部署一个应用
六、部署Dashboard和CoreDNS

一、系统环境初始化

1.1 k8s组件图

外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传

1.1.1 Master组件

kubectl

控制kubernetes集群

API Server

主要负责接收、校验并响应所有的REST请求，结果状态被持久存储在etcd当中，所有资源增删改查的唯一入口

Controller Manager

负责管理集群各种资源，保证资源处于预期的状态

Schedule

资源调度，负责决定将Pod放到哪个Node上运行

1.1.2 Node组件

kubelet

接收Schedule发送的node信息，根据信息创建和运行容器，并向master报告运行状态

Kube-proxy

负责将访问的service的数据请求转发到后端的pod容器

1.2 生产环境可部署Kubernetes集群的两种方式

目前生产部署Kubernetes集群主要有两种方式：

kubeadm

Kubeadm是一个K8s部署工具，提供kubeadm init和kubeadm join，用于快速部署Kubernetes集群。

官方地址：https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm/

二进制包

从github下载发行版的二进制包，手动部署每个组件，组成Kubernetes集群。

Kubeadm降低部署门槛，但屏蔽了很多细节，遇到问题很难排查。如果想更容易可控，推荐使用二进制包部署Kubernetes集群，虽然手动部署麻烦点，期间可以学习很多工作原理，也利于后期维护。

1.3 安装要求

在开始之前，部署Kubernetes集群机器需要满足以下几个条件：

一台或多台机器，操作系统 CentOS7.x-86_x64
硬件配置：2GB或更多RAM，2个CPU或更多CPU，硬盘30GB或更多
集群中所有机器之间网络互通
可以访问外网，需要拉取镜像，如果服务器不能上网，需要提前下载镜像并导入节点
禁止swap分区

1.4 环境准备

软件	版本
操作系统	CentOS Linux release 7.7.1611 (Core)
Docker	19-ce
Kubernetes	1.18

服务器整体规划：

角色	IP	组件
k8s-master	10.20.17.20	kube-apiserver，kube-controller-manager，kube-scheduler，etcd
k8s-node1	10.20.17.21	kubelet，kube-proxy，docker etcd
k8s-node2	10.20.17.22	kubelet，kube-proxy，docker，etcd

1.5 操作系统初始化配置

1.5.1 设置主机名

根据规划设置主机名（所有节点）

hostnamectl set-hostname <hostname>

1.5.2 设置hosts解析主机名

设置/etc/hosts保证主机名能够解析（所有节点）

# cat /etc/hosts
10.20.17.20 k8s-master
10.20.17.21 k8s-node1
10.20.17.22 k8s-node2

1.5.3 关闭SELinux和防火墙

所有节点

# 关闭防火墙
systemctl disable firewalld  永久
systemctl stop firewalld   临时


# 关闭selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
setenforce 0  # 临时

1.5.4 关闭swap

所有节点

swapoff -a  # 临时
sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久

1.5.5 设置系统参数

将桥接的IPv4流量传递到iptables的链（所有节点）

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

sysctl --system  # 生效

1.5.6 设置节点间的SSH免密码登录

所有节点

ssh-keygen -t rsa
ssh-copy-id k8s-master
ssh-copy-id k8s-node1
ssh-copy-id k8s-node2

1.5.7 安装docker环境

所有节点
可为docker设置一个阿里云镜像加速器

# cat /etc/docker/daemon.json
{
  "registry-mirrors": ["https://zn14eon5.mirror.aliyuncs.com"]
}

启动并设置开机启动

systemctl daemon-reload
systemctl start docker
systemctl enable docker

注：注册阿里云账号，获取专属加速地址阿里云镜像仓库

二、部署etcd集群

Etcd 是一个分布式键值存储系统，Kubernetes使用Etcd进行数据存储，所以先准备一个Etcd数据库，为解决Etcd单点故障，应采用集群方式部署，这里使用3台组建集群，可容忍1台机器故障，当然，你也可以使用5台组建集群，可容忍2台机器故障。

节点名称	IP
etcd-1	10.20.17.20
etcd-2	10.20.17.21
etcd-3	10.20.17.22

注：为了节省机器，这里与K8s节点机器复用。也可以独立于k8s集群之外部署，只要apiserver能连接到就行

2.1 准备cfssl证书生成工具

cfssl是一个开源的证书管理工具，使用json文件生成证书，相比openssl更方便使用。

找任意一台服务器操作，这里用Master节点。

mkdir -p /opt/tools
mkdir -p /opt/tools/cfssl
cd /opt/tools/cfssl/
wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo

2.2 生成Etcd证书

2.2.1 自签证书颁发机构（CA）

创建工作目录：

mkdir -p /root/TLS/{etcd,k8s}
mkdir -p /root/TLS/{etcd,k8s}
cd /root/TLS/etcd

自签CA：

cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "www": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF

cat > ca-csr.json << EOF
{
    "CN": "etcd CA",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing"
        }
    ]
}
EOF

生成证书：

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

ls *pem
ca-key.pem  ca.pem

2.2.2 使用自签CA签发Etcd HTTPS证书

创建证书申请文件：

cat > server-csr.json << EOF
{
    "CN": "etcd",
    "hosts": [
    "10.20.17.20",
    "10.20.17.21",
    "10.20.17.22"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing"
        }
    ]
}
EOF

注：上述文件hosts字段中IP为所有etcd节点的集群内部通信IP，一个都不能少！为了方便后期扩容可以多写几个预留的IP。

生成证书：

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server

ls server*pem
server-key.pem  server.pem

2.3 从Github下载etcd二进制文件

下载地址：https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz

2.4 部署Etcd集群

以下在etcd 节点1上操作，为简化操作，待会将节点1生成的所有文件拷贝到节点2和节点3。

2.4.1 创建工作目录并解压二进制包

mkdir -p /opt/etcd/{bin,cfg,ssl} 
tar zxvf /opt/tools/etcd-v3.4.9-linux-amd64.tar.gz
mv /opt/tools/etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

2.4.2 创建etcd配置文件

cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://10.20.17.20:2380"
ETCD_LISTEN_CLIENT_URLS="https://10.20.17.20:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://10.20.17.20:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://10.20.17.20:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://10.20.17.20:2380,etcd-2=https://10.20.17.21:2380,etcd-3=https://10.20.17.22:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF

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

2.4.3 systemd管理etcd

cat > /usr/lib/systemd/system/etcd.service << EOF
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd.conf
ExecStart=/opt/etcd/bin/etcd \
--cert-file=/opt/etcd/ssl/server.pem \
--key-file=/opt/etcd/ssl/server-key.pem \
--peer-cert-file=/opt/etcd/ssl/server.pem \
--peer-key-file=/opt/etcd/ssl/server-key.pem \
--trusted-ca-file=/opt/etcd/ssl/ca.pem \
--peer-trusted-ca-file=/opt/etcd/ssl/ca.pem \
--logger=zap
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF

2.4.4 拷贝刚才生成的证书

# cp /root/TLS/etcd/ca*pem /root/TLS/etcd/server*pem /opt/etcd/ssl/

2.4.5 将上面节点1所有生成的文件拷贝到节点2和节点3

scp -r /opt/etcd/ k8s-node1:/opt/
scp /usr/lib/systemd/system/etcd.service k8s-node1:/usr/lib/systemd/system/

scp -r /opt/etcd/ k8s-node2:/opt/
scp /usr/lib/systemd/system/etcd.service k8s-node2:/usr/lib/systemd/system/

然后在节点2和节点3分别修改etcd.conf配置文件中的节点名称和当前服务器IP：

[root@k8s-node1 bin]# vim /opt/etcd/cfg/etcd.conf

#[Member]
ETCD_NAME="etcd-1"  # 修改此处，节点2改为etcd-2，节点3改为etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://10.20.17.20:2380"  # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://10.20.17.20:2379"  # 修改此处为当前服务器IP
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://10.20.17.20:2380"  # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://10.20.17.20:2379"  # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://10.20.17.20:2380,etcd-2=https://10.20.17.21:2380,etcd-3=https://10.20.17.22:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

2.4.6 启动etcd服务并设置开机启动

systemctl daemon-reload    # 配置生效
systemctl start etcd       # 启动etcd
systemctl status etcd      # 查看启动状态
systemctl enable etcd      # 设置开机启动

注意：以上三个节点需要先启动其他节点的 etcd 而不是 master 的etcd ！！！

启动master节点的etcd服务后，发现服务无法启动，可使用 journalctl -xe 命令或查看系统日志cat /var/log/messages
看到以下关于etcd的报错信息：

"msg":"prober detected unhealthy status","round-tripper-name":"ROUND_TRIPPER_RAFT_MESSAGE","remote-peer-id":"427a09770fe3b784","rtt":"0s","error":"dial tcp 10.20.17.21:2380: connect: connection refused"

报错原因：分析是因为etcd1的配置文件/etc/systemd/system/etcd.service 启动脚本中的ETCD_INITIAL_CLUSTER_STATE是new，而在配置中ETCD_INITIAL_CLUSTER写入了etcd2/3的IP:PORT，这时etcd1尝试去连接etcd2、etcd3，但是etcd2、3的etcd服务此时还未启动，因此需要先启动etcd2和3的etcd服务，再去启动etcd1。

2.4.7 查看集群状态

# ETCDCTL_API=3 /opt/etcd/bin/etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://10.20.17.2017.21:2379,https://10.20.17.22:2379" endpoint health

https://10.20.17.20:2379 is healthy: successfully committed proposal: took = 11.989312ms
https://10.20.17.21:2379 is healthy: successfully committed proposal: took = 12.942844ms
https://10.20.17.22:2379 is healthy: successfully committed proposal: took = 29.3212ms

如果输出上面信息，就说明集群部署成功。如果有问题第一步先看日志：/var/log/message 或 journalctl -u etcd

三、部署Master Node

3.1 生成kube-apiserver证书

注：master节点操作

3.1.1 自签证书颁发机构（CA）

# cd /root/TLS/k8s/

cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF

cat > ca-csr.json << EOF
{
    "CN": "kubernetes",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF

生成证书：

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

ls *pem
ca-key.pem  ca.pem

3.2.2 使用自签CA签发kube-apiserver HTTPS证书

创建证书申请文件：

# cd /root/TLS/k8s/

cat > server-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "10.20.17.20",
      "10.20.17.21",
      "10.20.17.22",
      "kubernetes",
      "kubernetes.default",
      "kubernetes.default.svc",
      "kubernetes.default.svc.cluster",
      "kubernetes.default.svc.cluster.local"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF

注：上述文件hosts字段中IP为所有Master/LB/VIP IP，一个都不能少！为了方便后期扩容可以多写几个预留的IP。

生成证书：

# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare server

# ls server*pem
server-key.pem  server.pem

3.2 从Github下载二进制文件

下载地址： https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#v1183

注：打开链接你会发现里面有很多包，下载一个server包就够了，包含了Master和Worker Node二进制文件。

3.3 解压二进制包

注：master节点操作

mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 
cd /opt/tools/
tar zxvf kubernetes-server-linux-amd64.tar.gz

cd kubernetes/server/bin/
cp kube-apiserver kube-scheduler kube-controller-manager /opt/kubernetes/bi
cp kubectl /usr/bin/

3.4 部署kube-apiserver （master节点操作）

3.4.1 创建配置文件

cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--etcd-servers=https://10.20.17.20:2379,https://10.20.17.21:2379,https://10.20.17.22:2379 \\
--bind-address=10.20.17.20 \\
--secure-port=6443 \\
--advertise-address=10.20.17.20 \\
--allow-privileged=true \\
--service-cluster-ip-range=10.0.0.0/24 \\
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \\
--authorization-mode=RBAC,Node \\
--enable-bootstrap-token-auth=true \\
--token-auth-file=/opt/kubernetes/cfg/token.csv \\
--service-node-port-range=1000-65535 \\
--kubelet-client-certificate=/opt/kubernetes/ssl/server.pem \\
--kubelet-client-key=/opt/kubernetes/ssl/server-key.pem \\
--tls-cert-file=/opt/kubernetes/ssl/server.pem  \\
--tls-private-key-file=/opt/kubernetes/ssl/server-key.pem \\
--client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--etcd-cafile=/opt/etcd/ssl/ca.pem \\
--etcd-certfile=/opt/etcd/ssl/server.pem \\
--etcd-keyfile=/opt/etcd/ssl/server-key.pem \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF

注：上面两个\ \ 第一个是转义符，第二个是换行符，使用转义符是为了使用EOF保留换行符。

–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

3.4.2 拷贝刚才生成的证书

把刚才生成的证书拷贝到配置文件中的路径：

cp /root/TLS/k8s/ca*pem /root/TLS/k8s/server*pem /opt/kubernetes/ssl/

3.4.3 创建上述配置文件中token文件：

生成token

head -c 16 /dev/urandom | od -An -t x | tr -d ' '

创建token文件：

cat > /opt/kubernetes/cfg/token.csv << EOF
063e91e42837f2a2b36860457f515053,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF

3.4.4 systemd管理apiserver

cat > /usr/lib/systemd/system/kube-apiserver.service << EOF
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-apiserver.conf
ExecStart=/opt/kubernetes/bin/kube-apiserver \$KUBE_APISERVER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF

3.4.5 启动并设置开机启动

systemctl daemon-reload
systemctl start kube-apiserver
systemctl enable kube-apiserver

3.4.6 授权kubelet-bootstrap用户允许请求证书

kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap

3.5 部署kube-controller-manager

注：master节点操作

3.5.1 创建配置文件

cat > /opt/kubernetes/cfg/kube-controller-manager.conf << EOF
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect=true \\
--master=127.0.0.1:8080 \\
--bind-address=127.0.0.1 \\
--allocate-node-cidrs=true \\
--cluster-cidr=10.244.0.0/16 \\
--service-cluster-ip-range=10.0.0.0/24 \\
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \\
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem  \\
--root-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--experimental-cluster-signing-duration=87600h0m0s"
EOF

–master：通过本地非安全本地端口8080连接apiserver。
–leader-elect：当该组件启动多个时，自动选举（HA）
–cluster-signing-cert-file/–cluster-signing-key-file：自动为kubelet颁发证书的CA，与apiserver保持一致

3.5.2 systemd管理controller-manager

cat > /usr/lib/systemd/system/kube-controller-manager.service << EOF
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-controller-manager.conf
ExecStart=/opt/kubernetes/bin/kube-controller-manager \$KUBE_CONTROLLER_MANAGER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF

3.5.3 启动并设置开机启动

systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager

3.6 部署kube-scheduler

注：master节点操作

3.6.1 创建配置文件

cat > /opt/kubernetes/cfg/kube-scheduler.conf << EOF
KUBE_SCHEDULER_OPTS="--logtostderr=false \
--v=2 \
--log-dir=/opt/kubernetes/logs \
--leader-elect \
--master=127.0.0.1:8080 \
--bind-address=127.0.0.1"
EOF

–master：通过本地非安全本地端口8080连接apiserver。
–leader-elect：当该组件启动多个时，自动选举（HA）

3.6.2 systemd管理scheduler

cat > /usr/lib/systemd/system/kube-scheduler.service << EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-scheduler.conf
ExecStart=/opt/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
EOF

3.6.3 启动并设置开机启动

systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler

3.6.4 查看集群状态

所有组件都已经启动成功，通过kubectl工具查看当前集群组件状态：

[root@k8s-master ~]# kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"}   
etcd-1               Healthy   {"health":"true"}

四、部署Worker Node

下面还是在Master Node上操作，即同时作为Worker Node

4.1 创建工作目录并拷贝二进制文件

在所有worker node创建工作目录：（node节点操作）

mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs}

从master节点拷贝：（master节点操作）

cd /opt/tools/kubernetes/server/bin/
cp kubelet  kube-proxy /opt/kubernetes/bin/

scp kubelet  kube-proxy k8s-node1:/opt/kubernetes/bin/
scp kubelet  kube-proxy k8s-node2:/opt/kubernetes/bin/

4.2 部署kubelet

注：master节点操作

4.2.1 创建配置文件

cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-master \\
--network-plugin=cni \\
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \\
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \\
--config=/opt/kubernetes/cfg/kubelet-config.yml \\
--cert-dir=/opt/kubernetes/ssl \\
--pod-infra-container-image=mirrorgooglecontainers/pause-amd64:3.0"
EOF

–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

4.2.2 配置参数文件

cat > /opt/kubernetes/cfg/kubelet-config.yml << EOF
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 0.0.0.0
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS:
- 10.0.0.2
clusterDomain: cluster.local 
failSwapOn: false
authentication:
  anonymous:
    enabled: false
  webhook:
    cacheTTL: 2m0s
    enabled: true
  x509:
    clientCAFile: /opt/kubernetes/ssl/ca.pem 
authorization:
  mode: Webhook
  webhook:
    cacheAuthorizedTTL: 5m0s
    cacheUnauthorizedTTL: 30s
evictionHard:
  imagefs.available: 15%
  memory.available: 100Mi
  nodefs.available: 10%
  nodefs.inodesFree: 5%
maxOpenFiles: 1000000
maxPods: 110
EOF

4.2.3 生成bootstrap.kubeconfig文件

KUBE_APISERVER="https://10.20.17.20:6443" # apiserver IP:PORT
TOKEN="063e91e42837f2a2b36860457f515053" # 与token.csv里保持一致

cd /root/TLS/k8s

# 生成 kubelet bootstrap kubeconfig 配置文件
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=bootstrap.kubeconfig
  
kubectl config set-credentials "kubelet-bootstrap" \
  --token=${TOKEN} \
  --kubeconfig=bootstrap.kubeconfig
  
kubectl config set-context default \
  --cluster=kubernetes \
  --user="kubelet-bootstrap" \
  --kubeconfig=bootstrap.kubeconfig
  
  
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

拷贝到配置文件路径：

cp /root/TLS/k8s/bootstrap.kubeconfig /opt/kubernetes/cfg

4.2.4 systemd管理kubelet

cat > /usr/lib/systemd/system/kubelet.service << EOF
[Unit]
Description=Kubernetes Kubelet
After=docker.service
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet.conf
ExecStart=/opt/kubernetes/bin/kubelet \$KUBELET_OPTS
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF

4.2.5 启动并设置开机启动

systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet

注：若无法启动，可通过查看系统日志排查问题原因：cat /var/log/messages

4.3 批准kubelet证书申请并加入集群

# 查看kubelet证书请求
[root@k8s-master ~]# kubectl get csr
NAME                                                   AGE     SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-LHEDjWtPT39E8gkKemznF7a5GgEfX4Y5Q34E-MgzJbw   9m53s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 批准申请
kubectl certificate approve node-csr-LHEDjWtPT39E8gkKemznF7a5GgEfX4Y5Q34E-MgzJbw

# 查看节点
[root@k8s-master ~]# kubectl get node
NAME         STATUS     ROLES    AGE   VERSION
k8s-master   NotReady   <none>   21s   v1.18.3

注：由于网络插件还没有部署，节点会没有准备就绪 NotReady

4.4 部署kube-proxy

注：master节点操作

4.4.1 创建配置文件

cat > /opt/kubernetes/cfg/kube-proxy.conf << EOF
KUBE_PROXY_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--config=/opt/kubernetes/cfg/kube-proxy-config.yml"
EOF

4.4.2 配置参数文件

cat > /opt/kubernetes/cfg/kube-proxy-config.yml << EOF
kind: KubeProxyConfiguration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
metricsBindAddress: 0.0.0.0:10249
clientConnection:
  kubeconfig: /opt/kubernetes/cfg/kube-proxy.kubeconfig
hostnameOverride: k8s-master
clusterCIDR: 10.0.0.0/24
EOF

4.4.3 生成kube-proxy.kubeconfig文件

生成kube-proxy证书：

# 切换工作目录
cd /root/TLS/k8s

# 创建证书请求文件
cat > kube-proxy-csr.json << EOF
{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}
EOF

# 生成证书
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy

ls kube-proxy*pem
kube-proxy-key.pem  kube-proxy.pem

生成kubeconfig文件：


KUBE_APISERVER="https://10.20.17.20:6443"

cd /root/TLS/k8s

kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/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

拷贝到配置文件指定路径：

cp /root/TLS/k8s/kube-proxy.kubeconfig /opt/kubernetes/cfg/

4.4.4 systemd管理kube-proxy

cat > /usr/lib/systemd/system/kube-proxy.service << EOF
[Unit]
Description=Kubernetes Proxy
After=network.target
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-proxy.conf
ExecStart=/opt/kubernetes/bin/kube-proxy \$KUBE_PROXY_OPTS
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF

4.4.5 启动并设置开机启动

systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy

4.5 部署CNI网络

注：master节点操作

4.5.1 准备CNI二进制文件

下载地址：https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz

4.5.2 解压二进制包并移动到默认工作目录

mkdir -p /opt/cni/bin
cd /opt/tools/
tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin

4.5.3 部署CNI网络

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

# 若默认镜像地址无法访问，修改为docker hub镜像仓库。此处我们不进行修改
sed -i -r "s#quay.io/coreos/flannel:.*-amd64#lizhenliang/flannel:v0.12.0-amd64#g" kube-flannel.yml

生成flannel网络容器：

# kubectl apply -f kube-flannel.yml

# kubectl get pods -n kube-system
NAME                          READY   STATUS    RESTARTS   AGE
kube-flannel-ds-amd64-c4t2v   1/1     Running   0          25s

# kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    <none>   36m   v1.18.3

部署好网络插件，Node准备就绪。

4.6 授权apiserver访问kubelet

注：master节点操作

cat > apiserver-to-kubelet-rbac.yaml << EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:kube-apiserver-to-kubelet
rules:
  - apiGroups:
      - ""
    resources:
      - nodes/proxy
      - nodes/stats
      - nodes/log
      - nodes/spec
      - nodes/metrics
      - pods/log
    verbs:
      - "*"
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: system:kube-apiserver
  namespace: ""
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:kube-apiserver-to-kubelet
subjects:
  - apiGroup: rbac.authorization.k8s.io
    kind: User
    name: kubernetes
EOF

kubectl apply -f apiserver-to-kubelet-rbac.yaml

4.7 新增加Worker Node

4.7.1 拷贝已部署好的Node相关文件到新节点

master节点操作

在master节点将Worker Node涉及文件拷贝到新节点：node1 、node2

scp -r /opt/kubernetes k8s-node1:/opt/
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service k8s-node1:/usr/lib/systemd/system
scp -r /opt/cni/ k8s-node1:/opt/
scp /opt/kubernetes/ssl/ca.pem k8s-node1:/opt/kubernetes/ssl

4.7.2 删除kubelet证书和kubeconfig文件

node节点操作

rm /opt/kubernetes/cfg/kubelet.kubeconfig 
rm -f /opt/kubernetes/ssl/kubelet*

注：这几个文件是证书申请审批后自动生成的，每个Node不同，必须删除重新生成。

4.7.3 修改主机名

node节点操作

vim /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node1

vim /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-node1

4.7.4 启动并设置开机启动

node 节点操作

systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet
systemctl start kube-proxy
systemctl enable kube-proxy

4.7.5 在Master上批准新Node kubelet证书申请

master节点操作

# kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-LHEDjWtPT39E8gkKemznF7a5GgEfX4Y5Q34E-MgzJbw   68m   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Approved,Issued
node-csr-eFXMlBTEP1jYeRrMur_ZdpMeWyKmtyQ-A_LGOQZ74a0   57s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

kubectl certificate approve node-csr-eFXMlBTEP1jYeRrMur_ZdpMeWyKmtyQ-A_LGOQZ74a0

4.7.6 查看Node状态

master节点操作

[root@k8s-master ~]# kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    <none>   60m   v1.18.3
k8s-node1    Ready    <none>   62s   v1.18.3

注：若新加的节点状态为NotReady时，可使用journalctl -f -u kubelet 检查问题，若为以下报错：

 Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:docker: network plugin is not ready: cni config uninitialized

此问题为网络插件没有准备好，我们可以执行命令docker images|grep flannel来查看flannel镜像是否已经成功拉取下来.经过排查,flannel镜像拉取的有点慢,稍等一会以后就可以了，或者手动执行命令下载镜像：docker pull quay.io/coreos/flannel:v0.12.0-amd64

若需要继续添加node节点2，同上操作即可，记得修改主机名！

五、部署一个应用

5.1 创建一个yaml文件存放目录

mkdir /opt/k8s-yaml

5.2 编写deployment的yaml文件

# cat test-sea-pc-qianduan-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: test-sea-pc-qianduan
  name: test-sea-pc-qianduan-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      app: test-sea-pc-qianduan
  template:
    metadata:
      labels:
        app: test-sea-pc-qianduan
    spec:
      containers:
      - image: test-sea-pc-qianduan:test01
        imagePullPolicy: Never
        #command: [ "/bin/bash", "-ce", "tail -f /dev/null" ]
        livenessProbe:
          initialDelaySeconds: 30
          periodSeconds: 30
          tcpSocket:
            port: 15190
        name: test-sea-pc-qianduan
        ports:
        - containerPort: 15190
        readinessProbe:
          initialDelaySeconds: 30
          periodSeconds: 30
          tcpSocket:
            port: 15190
        volumeMounts:
        - mountPath: /etc/localtime
          name: host-time
        - mountPath: /opt/data/
          name: file
      imagePullSecrets:
      - name: harbor-secret
      restartPolicy: Always
      volumes:
      - hostPath:
          path: /etc/localtime
        name: host-time
      - hostPath:
          path: /opt/logs/gfs/test-sea/pc-qianduan
        name: file

5.3 编写service的yaml文件

# cat test-sea-pc-qianduan-service.yaml 
apiVersion: v1
kind: Service
metadata:
  name: test-sea-pc-qianduan-service-nodeport
  namespace: default
spec:
  clusterIP: 10.0.0.6
  ports:
  - name: http
    nodePort: 25210
    port: 15190
    protocol: TCP
    targetPort: 15190
  selector:
    app: test-sea-pc-qianduan
  type: NodePort

5.4 生成应用pod容器

# kubectl create -f test-sea-pc-qianduan-deployment.yaml
deployment.apps/test-sea-pc-qianduan-deployment created

# kubectl get pod
NAME                                               READY   STATUS    RESTARTS   AGE
test-sea-pc-qianduan-deployment-566b7697f9-4xxh2   1/1     Running   0          61s

5.5 生成应用service

# kubectl create -f test-sea-pc-qianduan-service.yaml
service/test-sea-pc-qianduan-service-nodeport created

# kubectl get svc
NAME                                    TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)           AGE
kubernetes                              ClusterIP   10.0.0.1     <none>        443/TCP           3h42m
test-sea-pc-qianduan-service-nodeport   NodePort    10.0.0.6     <none>        15190:25210/TCP   17s

注：启动漫service时若报错：

The Service "test-sea-pc-qianduan-service-nodeport" is invalid: spec.ports[0].nodePort: Invalid value: 25210: provided port is not in the valid range. The range of valid ports is 30000-32767
解决方法 ： 编辑 kube-apiserver.yaml文件
vim /opt/kubernetes/cfg/kube-apiserver.conf

找到 --service-cluster-ip-range 这一行，在这一行的下一行修改 如下内容

--service-node-port-range=1-65535
重启kube-apiserver

systemctl restart kube-apiserver

5.6 访问验证

服务器测试：
curl http://127.0.0.1:25210

或在浏览器中测试：
http://10.20.17.20:25210/

六、部署Dashboard和CoreDNS

6.1 部署 Dashboard

6.1.1 下载Dashboard的yaml文件

wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta8/aio/deploy/recommended.yaml

默认Dashboard只能集群内部访问，修改Service为NodePort类型，暴露到外部：

vim recommended.yaml
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
   - port: 443
     targetPort: 8443
     nodePort: 30001
  type: NodePort
  selector:
    k8s-app: kubernetes-dashboard

6.1.2 部署Dashboard服务

# kubectl apply -f recommended.yaml

# kubectl get pods,svc -n kubernetes-dashboard
NAME                                             READY   STATUS    RESTARTS   AGE
pod/dashboard-metrics-scraper-694557449d-pzjvv   1/1     Running   0          20s
pod/kubernetes-dashboard-9774cc786-8mprh         1/1     Running   0          20s

NAME                                TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
service/dashboard-metrics-scraper   ClusterIP   10.0.0.230   <none>        8000/TCP        20s
service/kubernetes-dashboard        NodePort    10.0.0.24    <none>        443:30001/TCP   20s

访问地址：https://NodeIP:30001

6.1.3 创建service account并绑定默认cluster-admin管理员集群角色

# kubectl create serviceaccount dashboard-admin -n kube-system


# kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin


# kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')

使用输出的token登录Dashboard。

6.2 部署CoreDNS

注：CoreDNS用于集群内部Service名称解析。

6.2.1 生成CoreDNS的yaml文件

mkdir /opt/tools/coredns &&  cd /opt/tools/coredns/
 
wget https://raw.githubusercontent.com/coredns/deployment/master/kubernetes/coredns.yaml.sed
wget https://raw.githubusercontent.com/coredns/deployment/master/kubernetes/deploy.sh
chmod +x deploy.sh

./deploy.sh -i 10.0.0.2 > coredns.yml

注：10.0.0.2应该是k8s集群中pod地址段中的IP

注：生成CoreDNS的yaml文件需要jq命令

CentOS7安装 jq

#安装EPEL源：
yum install epel-release

#安装jq：
yum install jq

6.2.2 部署coredns服务

kubectl apply -f coredns.yml

6.2.3 查看coredns服务是否成功创建

# kubectl get pods -n kube-system 
NAME                          READY   STATUS    RESTARTS   AGE
coredns-6fdfb45d56-qv8hl      1/1     Running   0          2m7s
kube-flannel-ds-amd64-bnbrf   1/1     Running   3          43h
kube-flannel-ds-amd64-mtn2f   1/1     Running   2          44h

6.2.4 DNS解析测试

# 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


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

Name:      www.baidu.com
Address 1: 240e:83:205:59:0:ff:b09b:159e
Address 2: 240e:83:205:58:0:ff:b09f:36bf
Address 3: 220.181.38.150
Address 4: 220.181.38.149

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

Name:      www.zhihu.com
Address 1: 42.81.85.241
Address 2: 42.81.92.66
Address 3: 42.81.92.60

解析没问题。