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部署Kubernetes集群(二进制 v1.18.5版)

部署Kubernetes集群(二进制 v1.18.5版)

作者: Linux丶晨星 | 来源:发表于2020-07-16 18:07 被阅读0次

    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 <<EOF
    {
        "CN": "etcd",
        "hosts": [
        "192.168.0.10",
        "192.168.0.20",
        "192.168.0.30"
        ],
        "key": {
            "algo": "rsa",
            "size": 2048
        },
        "names": [
            {
                "C": "CN",
                "L": "BeiJing",
                "ST": "BeiJing"
            }
        ]
    }
    EOF
    

    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 <<EOF
    ${BOOTSTRAP_TOKEN},kubelet-bootstrap,10001,"system:node-bootstrapper"
    EOF
    

    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   <none>   1s    v1.18.5
    k8s-node2   NotReady   <none>   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

    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    <none>   2m3s   v1.18.5
    k8s-node2   Ready    <none>   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   <none>        8000/TCP        35s
    service/kubernetes-dashboard        NodePort    10.0.0.80    <none>        443:30001/TCP   35s
    

    查看pod日志

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

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