部署Kubernetes集群(二进制 v1.18.5版)

一、Kubernetes的基本知识

  1. Pod
    Pod是若干个相关容器的组合,是一个逻辑概念,Pod包含的容器运行在同一个宿主机上,这些容器使用相同的网络命名空间、IP地址和端口,相互之间能通过localhost来发现和通信,共享一块存储卷空间。在Kubernetes中创建、调度和管理的最小单位是Pod。一个Pod一般只放一个业务容器和一个用于统一网络管理的网络容器。

  2. Replication Controller
    Replication Controller是用来控制管理Pod副本(Replica,或者称实例),Replication Controller确保任何时候Kubernetes集群中有指定数量的Pod副本在运行,如果少于指定数量的Pod副本,Replication Controller会启动新的Pod副本,反之会杀死多余的以保证数量不变。另外Replication Controller是弹性伸缩、滚动升级的实现核心。

  3. Service
    Service是真实应用服务的抽象,定义了Pod的逻辑集合和访问这个Pod集合的策略,Service将代理Pod对外表现为一个单一访问接口,外部不需要了解后端Pod如何运行,这给扩展或维护带来很大的好处,提供了一套简化的服务代理和发现机制。

  4. Label
    Label是用于区分Pod、Service、Replication Controller的Key/Value键值对,实际上Kubernetes中的任意API对象都可以通过Label进行标识。每个API对象可以有多个Label,但是每个Label的Key只能对应一个Value。Label是Service和Replication Controller运行的基础,它们都通过Label来关联Pod,相比于强绑定模型,这是一种非常好的松耦合关系。

  5. Node
    Kubernets属于主从的分布式集群架构,Kubernets Node(简称为Node,早期版本叫做Minion)运行并管理容器。Node作为Kubernetes的操作单元,将用来分配给Pod(或者说容器)进行绑定,Pod最终运行在Node上,Node可以认为是Pod的宿主机。

需求

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。

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. 安装要求

部署Kubernetes集群服务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
  • 禁止swap分区

软件环境:

软件 版本
操作系统 CentOS7.6.1810
Docker docker-ce 19.03.11
Kubernetes 1.18

服务器整体规划:

角色 IP 组件
k8s-master1 192.168.0.10 kube-apiserver,kube-controller-manager,kube-scheduler,etcd
k8s-master2 192.168.0.11 kube-apiserver,kube-controller-manager,kube-scheduler,etcd
k8s-node1 192.168.0.20 kubelet,kube-proxy,docker,etcd
k8s-node2 192.168.0.30 kubelet,kube-proxy,docker,etcd
Load Balancer (master) 192.168.0.40 nginx L4 ,master节点的高可用 192.168.0.41(VIP)
Load Balancer (Backup) 192.168.0.41 nginx L4

须知:考虑电脑配置环境较低,这么多虚拟机跑不动,所以这一套高可用集群分两部分实施,先部署一套单Master架构(192.168.0.10/20/30),再扩容为多Master架构(上述规划)。

单Master节点服务器规划:

角色 IP 组件
k8s-master 192.168.0.10 kube-apiserver,kube-controller-manager,kube-scheduler,etcd
k8s-node1 192.168.0.20 kubelet,kube-proxy,docker etcd
k8s-node2 192.168.0.30 kubelet,kube-proxy,docker,etcd
kubernetes架构图

2. 系统初始化配置

# 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld

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

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

# 根据规划设置主机名
hostnamectl set-hostname < name >

# 在master添加hosts
cat >> /etc/hosts << EOF
192.168.0.10 k8s-master
192.168.0.20 k8s-node1
192.168.0.30 k8s-node2
EOF

# 将桥接的IPv4流量传递到iptables的链
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  # 生效
sysctl -p /etc/sysctl.d/k8s.conf

# 时间同步
yum install ntpdate -y
ntpdate time.windows.com
组件 使用的证书
etcd ca.pem,server.pem,server-key.pem
flannel ca.pem,server.pem,server-key.pem
kube-apiserver ca.pem,server.pem,server-key.pem
kubelet(自动颁发) ca.pem,ca-key.pem
kube-proxy ca.pem,kube-proxy.pem,kube-proxy-key.pem
kubectl ca.pem,admin.pem,admin-key.pem

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 (k8s-master) 192.168.0.10
etcd-2 (k8s-node1) 192.168.0.20
etcd-3 (k8s-node2) 192.168.0.30

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api-server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。这里用Master节点。

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 ~/TLS/{etcd,k8s}
cd TLS/etcd
# 自签CA
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": "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

[root@k8s-master etcd]# ll *pem
-rw-------. 1 root root 1675 Jul 10 15:32 ca-key.pem
-rw-r--r--. 1 root root 1265 Jul 10 15:32 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 <

注: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!为了方便后期扩容也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

[root@k8s-master etcd]# ll server*pem
-rw-------. 1 root root 1679 Jul 10 15:38 server-key.pem
-rw-r--r--. 1 root root 1338 Jul 10 15:38 server.pem

2.3 从Github下载Etcd二进制文件

# 下载地址
#官网写了,因为新版3.4以上版本不支持旧版API,建议换成3.3的etcd
wget 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

在master节点上操作,为简化操作,可以将master节点生成的所有文件拷贝到俩台node节点

2.4.1 创建目录并解压二进制包

mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxvf etcd-v3.3.22-linux-amd64.tar.gz
chown -R root:root etcd-v3.3.22-linux-amd64
mv etcd-v3.3.22-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://192.168.0.10:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.0.10:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.0.10:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.0.10:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.0.10:2380,etcd-2=https://192.168.0.20:2380,etcd-3=https://192.168.0.30:2380"
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 配置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

2.4.3 拷贝生成的证书

把刚才生成的证书拷贝到配置文件中的路径

cp ~/TLS/etcd/ca*pem ~/TLS/etcd/server*pem /opt/etcd/ssl/

2.4.5 启动并设置自启动

systemctl daemon-reload
systemctl restart etcd
systemctl enable etcd

# 如果报错无法启动,则需要将其他etcd节点设置完成后才可以启动

2.4.6 将master节点生成所有的文件拷贝到两台node节点

scp -rp /opt/etcd/ k8s-node1:/opt/
scp -rp /opt/etcd/ k8s-node2:/opt/

scp -rp /usr/lib/systemd/system/etcd.service k8s-node1:/usr/lib/systemd/system/
scp -rp /usr/lib/systemd/system/etcd.service k8s-node2:/usr/lib/systemd/system/

2.4.7 在node节点分别修改etcd.conf配置文件中的节点名称和当前服务器IP

#node1和node2节点都进行修改
vim /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-2"  # 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"  # 修改此处为当前服务器IP
ETCD_LISTEN_PEER_URLS="https://192.168.0.20:2380"   # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://192.168.0.20:2379" # 修改此处为当前服务器IP

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.0.20:2380"    # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.0.20:2379"  # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.0.10:2380,etcd-2=https://192.168.0.20:2380,etcd-3=https://192.168.0.30:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"


# 最后启动etcd并设置开机启动
systemctl daemon-reload
systemctl restart etcd
systemctl enable etcd

[root@k8s-master etcd]# netstat -lntup|grep etcd
tcp        0      0 192.168.0.10:2379       0.0.0.0:*               LISTEN      10529/etcd          
tcp        0      0 192.168.0.10:2380       0.0.0.0:*               LISTEN      10529/etcd 

#为三台节点都创建系统执行指令命令
cp /opt/etcd/bin/etcdctl /usr/bin/

2.4.8 查看etcd集群状态

[root@k8s-master etcd]# etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://192.168.0.10:2379,https://192.168.0.20:2379,https://192.168.0.30:2379" endpoint health
https://192.168.0.30:2379 is healthy: successfully committed proposal: took = 18.649662ms
https://192.168.0.20:2379 is healthy: successfully committed proposal: took = 20.469511ms
https://192.168.0.10:2379 is healthy: successfully committed proposal: took = 22.428573ms

如果输出上面信息,就说明Etcd集群部署成功。如果有问题先看日志:/var/log/messagejournalctl -u etcd

三、所有节点部署Docker

image

我这里采用yum安装,用二进制安装也一样

二进制包下载链接

# 1. 卸载旧版本
yum remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-engine
                  
# 2. 使用存储库安装
yum install -y yum-utils

# 3. 设置镜像仓库(修改为国内源地址)
yum-config-manager \
    --add-repo \
    http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

# 5. 更新索引
yum makecache fast

# 4. 安装docker相关的依赖 默认最新版(docker-ce:社区版 ee:企业版)
yum install docker-ce docker-ce-cli containerd.io -y

#5. 安装特定docker版本(先列出列出可用版本)
yum list docker-ce --showduplicates | sort -r
yum install docker-ce-19.03.9 docker-ce-cli-19.03.9 containerd.io

# 所有节点设置防火墙规则,并让生效
vim /lib/systemd/system/docker.service
[Service]
ExecStartPost=/sbin/iptables -I FORWARD -s 0.0.0.0/0 -j ACCEPT

# 7. 启动docker
systemctl enable docker
systemctl restart docker

# 8. 查看版本
[root@k8s-master ~]# docker --version
Docker version 19.03.11, build 42e35e61f3

# 9. 配置docker镜像加速器
## 镜像加速器:阿里云加速器,daocloud加速器,中科大加速器
## Docker 中国官方镜像加速:https://registry.docker-cn.com
mkdir -p /etc/docker
tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://registry.docker-cn.com"]
}
EOF
systemctl daemon-reload
systemctl restart docker

四、部署Master节点

  • kube-apiserver,

  • kube-controller-manager,

  • kube-scheduler

4.1 生成kube-apiserver证书

4.1.1 自签CA证书颁发机构

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 -

[root@k8s-master k8s]# ll *pem
-rw-------. 1 root root 1675 Jul 13 14:49 ca-key.pem
-rw-r--r--. 1 root root 1359 Jul 13 14:49 ca.pem

4.1.2 使用自签CA签发kube-apiserver HTTPS证书

# 创建证书申请文件:
cat > server-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "10.240.0.1",
      "172.16.0.1",
      "127.0.0.1",
      "192.168.0.10",
      "192.168.0.11",
      "192.168.0.12",
      "192.168.0.20",
      "192.168.0.21",
      "192.168.0.22",
      "192.168.0.30",
      "192.168.0.31",
      "192.168.0.32",
      "192.168.0.40",
      "192.168.0.41",
      "192.168.0.42",
      "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

#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

[root@k8s-master k8s]# ll server*pem
-rw-------. 1 root root 1679 Jul 13 14:55 server-key.pem
-rw-r--r--. 1 root root 1700 Jul 13 14:55 server.pem

4.2下载二进制文件包并解压

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

打开链接会发现里面有很多包,下载一个最新版server包就够了,包含了Master和Node二进制文件。

# 解压二进制包
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 
tar zxvf kubernetes-server-linux-amd64.tar.gz
cd ./kubernetes/server/bin/
cp kube-apiserver kube-scheduler kube-controller-manager /opt/kubernetes/bin
cp kubectl /usr/bin/

4.3 部署kube-apiserver

4.3.1. 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://192.168.0.10:2379,https://192.168.0.20:2379,https://192.168.0.30:2379 \\
--bind-address=192.168.0.10 \\
--secure-port=6443 \\
--advertise-address=192.168.0.10 \\
--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=30000-32767 \\
--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
--log-dir:日志目录
--v:日志等级,越小越多
--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,决定是否启用k8s高级功能
--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-https:apiserver主动访问kubectl时默认使用https
--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

启用 TLS Bootstrapping 机制

TLS Bootstraping:Master apiserver启用TLS认证后,Node节点kubelet和kube-proxy要与kube-apiserver进行通信,必须使用CA签发的有效证书才可以,当Node节点很多时,这种客户端证书颁发需要大量工作,同样也会增加集群扩展复杂度。为了简化流程,Kubernetes引入了TLS bootstraping机制来自动颁发客户端证书,kubelet会以一个低权限用户自动向apiserver申请证书,kubelet的证书由apiserver动态签署。所以强烈建议在Node上使用这种方式,目前主要用于kubelet,kube-proxy还是由我们统一颁发一个证书。

此图仅用来学习,不为本人原创

image

4.3.2 拷贝刚才生成的证书

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

4.3.3 创建配置文件中的token文件

# 获取16位token随机值的命令
head -c 16 /dev/urandom | od -An -t x | tr -d ' '
863b2ebebecffbb3a6493ff15dfc57c6

# 添加token文件(格式:token,用户名,UID,用户组)
BOOTSTRAP_TOKEN=863b2ebebecffbb3a6493ff15dfc57c6
cat > /opt/kubernetes/cfg/token.csv <

4.3.4 配置systemd启动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

4.3.5 启动并设置开机启动

systemctl daemon-reload
systemctl restart kube-apiserver
systemctl enable kube-apiserver

4.3.6 授权kubelet-bootstrapper用户允许请求证书

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

4.4 部署controller-manager

5.4.1 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

4.4.2 配置systemd启动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

4.4.3 启动并设置开机启动

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

4.5 部署kube-scheduler

4.5.1 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)

4.5.2 配置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

4.5.3 启动并设置开机启动

systemctl daemon-reload
systemctl restart kube-scheduler
systemctl enable kube-scheduler

4.6 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 TLS]# kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   
etcd-1               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"}  

输出如上内容说明Master节点组件运行正常

五、部署Node节点

5.1 创建工作目录并拷贝二进制文件

如果想把Master也当做Node节点的话,也可以在Master节点上安装kubelet和kube-proxy

# 1.在所有node节点创建工作目录
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 

# 2. 从master节点上解压的kubernetes压缩包中拷贝文件到所有node节点
for ip in 20 30 ;do scp -rp ./kubernetes/server/bin/{kubelet,kube-proxy} 192.168.0.$ip:/opt/kubernetes/bin/ ;done

5.2 部署kubelet

5.2.1 创建配置文件

pod的基础容器镜像改为国内的下载的镜像地址或自己的Docker Hub

registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0

245684979/pause-amd64:3.0

# node1节点
cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-node1 \\
--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=245684979/pause-amd64:3.0"
EOF

# node2节点
cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-node2 \\
--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=245684979/pause-amd64:3.0"
EOF
  • –hostname-override:显示主机名称,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,用于实现Kubernetes集群里pod之间的网络通讯

5.2.2 配置参数文件

# node1节点和node2节点配置相同
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

5.2.3 生成bootstrap.kubeconfig文件

在master节点将node节点需要的CA证书文件拷贝过去

[root@k8s-master ~]# scp /opt/kubernetes/ssl/ca.pem k8s-node1:/opt/kubernetes/ssl
[root@k8s-master ~]# scp /opt/kubernetes/ssl/ca.pem k8s-node2:/opt/kubernetes/ssl

在master上查看Token文件的随机值

[root@k8s-master ~]# cat /opt/kubernetes/cfg/token.csv 
863b2ebebecffbb3a6493ff15dfc57c6,kubelet-bootstrap,10001,"system:kubelet-bootstrapper"

在master上生成bootstrap.kubeconfig文件

KUBE_APISERVER="https://192.168.0.10:6443" # apiserverIP:PORT
TOKEN="863b2ebebecffbb3a6493ff15dfc57c6" # 与token.csv里保持一致

# 设置集群参数
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=bootstrap.kubeconfig
  
# 设置客户端认证参数
kubectl config set-credentials "kubelet-bootstrap" \
  --token=${TOKEN} \
  --kubeconfig=bootstrap.kubeconfig
  
# 设置上下文参数
kubectl config set-context default \
  --cluster=kubernetes \
  --user="kubelet-bootstrap" \
  --kubeconfig=bootstrap.kubeconfig
  
# 设置默认上下文
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

# 保存到配置文件路径下
cp bootstrap.kubeconfig /opt/kubernetes/cfg/

# 拷贝到node节点的/opt/kubernetes/cfg/下
scp -rp /opt/kubernetes/cfg/bootstrap.kubeconfig k8s-node1:/opt/kubernetes/cfg
scp -rp /opt/kubernetes/cfg/bootstrap.kubeconfig k8s-node2:/opt/kubernetes/cfg

5.2.4 配置systemd管理kubelet

# node1节点和node2节点配置相同
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

5.2.5 启动并设置开机启动

systemctl daemon-reload
systemctl restart kubelet
systemctl enable kubelet

5.2.6 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-1-0ue-UfiHoWna5v68PDMgrxk1cPPNFLG3EtoUUCdwk   85s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending
node-csr-zjBOatKIi69UhbL7ypngHFw5C7xfjCOZnFyTG4Ux1H0   76s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 批准请求
kubectl certificate approve node-csr-1-0ue-UfiHoWna5v68PDMgrxk1cPPNFLG3EtoUUCdwk
kubectl certificate approve node-csr-zjBOatKIi69UhbL7ypngHFw5C7xfjCOZnFyTG4Ux1H0

# 查看node节点状态
[root@k8s-master ~]# kubectl get nodes
NAME           STATUS     ROLES    AGE   VERSION
k8s-node1   NotReady      1s    v1.18.5
k8s-node2   NotReady      1s    v1.18.5
#@注:由于网络插件还没有部署,节点会没有准备就绪 NotReady

5.4 部署kube-proxy

5.4.1 创建配置文件

# node1节点和node2节点配置相同
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

5.4.2 配置参数文件

# node1
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-node1
clusterCIDR: 10.0.0.0/24
EOF

# node2
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-node2
clusterCIDR: 10.0.0.0/24
EOF

5.4.3 生成kube-proxy.kubeconfig文件

在master节点生成kube-proxy证书

# 切换到存放证书目录
cd ~/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

[root@k8s-master k8s]# ll kube-proxy*pem
-rw-------. 1 root root 1679 Jul 14 15:41 kube-proxy-key.pem
-rw-r--r--. 1 root root 1403 Jul 14 15:41 kube-proxy.pem

5.4.3 生成kube-proxy.kubeconfig文件

在master节点生成kube-proxy.kubeconfig文件

KUBE_APISERVER="https://192.168.0.10:6443"

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

# 保存到配置文件路径下
cp kube-proxy.kubeconfig /opt/kubernetes/cfg/

# 拷贝到node节点的/opt/kubernetes/cfg/下
scp -rp /opt/kubernetes/cfg/kube-proxy.kubeconfig k8s-node1:/opt/kubernetes/cfg
scp -rp /opt/kubernetes/cfg/kube-proxy.kubeconfig k8s-node2:/opt/kubernetes/cfg

5.4.4 配置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

5.4.5 启动并设置开机启动

systemctl daemon-reload
systemctl restart kube-proxy
systemctl enable kube-proxy

六、部署CNI网络

6.1 Kubernetes网络模型 (CNI)介绍

  • kubernetes集群的网络官方文档

  • github上的CNI文档

容器网络接口

kubernetes网络模型设计的基本要求:

  • 一个pod一个ip
  • 每个pod独立的ip,pod内所有容器共享网络(同一个ip)
  • 所有容器都可以与所有其他容器通信
  • 所有节点都可以与所有容器通信

目前支持的技术

.
image

最常用的是flannel和calic

  • Flannel:适合百台以下服务器,小规模集群,使用操作简单
  • calico:适合数百台以上,大规模集群

6.2 下载安装包

下载最新版地址:https://github.com/containernetworking/plugins/releases/tag/v0.8.6

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

# 解压二进制包并移动到默认工作目录
mkdir -p /opt/cni/bin
tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin

# 在node节点创建cni目录
mkdir -p /opt/cni/bin

# 在master节点上拷贝到node节点的cni目录
scp -rp /opt/cni/bin/* k8s-node1:/opt/cni/bin/
scp -rp /opt/cni/bin/* k8s-node2:/opt/cni/bin/

6.3 部署CNI flannel 网络

所有的节点都需要安装flannel

# 部署CNI网络(网络问题可以多尝试几次)
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

# 默认镜像地址无法访问外网,可以修改为docker hub镜像仓库
# 245684979/flannel:v0.12.0-amd64
sed -ri "s#quay.io/coreos/flannel:.*-amd64#245684979/flannel:v0.11.0-amd64#g" kube-flannel.yml

#添加"--iface=eth0"一句指定网卡
...
containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.12.0-amd64
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        - --iface=eth0
[root@k8s-master ~]# kubectl apply -f kube-flannel.yml

#查看kube-system下的pod
[root@k8s-master cni]# kubectl get pods -n kube-system
NAME                          READY   STATUS    RESTARTS   AGE
kube-flannel-ds-amd64-lklmb   1/1     Running   0          74s
kube-flannel-ds-amd64-t5tcc   1/1     Running   0          74s

#查看node状态
[root@k8s-master ~]# kubectl get nodes
NAME        STATUS   ROLES    AGE    VERSION
k8s-node1   Ready       2m3s   v1.18.5
k8s-node2   Ready       104s   v1.18.5

6.4 授权apiserver访问kubelet

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

八、部署Dashboard和CoreDNS

8.1 部署Dashboard

https://github.com/kubernetes/dashboard

wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.3/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

# 修改yaml文件
[root@k8s-master yaml]# vim recommended.yaml    (32gg)
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001       #添加类型
  type: NodePort
  selector:
    k8s-app: kubernetes-dashboard


# 生成dashboard
kubectl apply -f recommended.yaml

# 查看dashboard状态
[root@k8s-master yaml]# kubectl get pods,svc -n kubernetes-dashboard
NAME                                             READY   STATUS              RESTARTS   AGE
pod/dashboard-metrics-scraper-6b4884c9d5-gqs7b   0/1     ContainerCreating   0          34s
pod/kubernetes-dashboard-7f99b75bf4-mgg46        0/1     ContainerCreating   0          35s

NAME                                TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
service/dashboard-metrics-scraper   ClusterIP   10.0.0.105           8000/TCP        35s
service/kubernetes-dashboard        NodePort    10.0.0.80            443:30001/TCP   35s

查看pod日志

 kubectl -n kube-system  logs -f  kube-flannel-ds-amd64-24jxf

你可能感兴趣的:(部署Kubernetes集群(二进制 v1.18.5版))