侧边栏壁纸
博主头像
汪洋

即使慢,驰而不息,纵会落后,纵会失败,但一定可以达到他所向的目标。 - 鲁迅

  • 累计撰写 190 篇文章
  • 累计创建 74 个标签
  • 累计收到 108 条评论

Kubernetes - 二进制文件构建 V1.22.0

汪洋
2022-05-20 / 11 评论 / 5 点赞 / 1,572 阅读 / 37,595 字

一、前置知识点

1.1 生产环境部署 K8s 集群的两种方式

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

优缺点分析
  • kubeadm
    • 降低部署门槛
    • 所有组件均以容器化运行
    • 自愈
  • 二进制包部署
    • 更可控
    • 排查问题较为清晰
    • 更便于理解组件结构

1.2 准备环境

服务器要求

• 建议最小硬件配置:2核CPU、2G内存、30G硬盘

• 服务器最好可以访问外网,会有从网上拉取镜像需求,如果服务器不能上网,需要提前下载对应镜像并导入节点

所需软件包

链接:https://pan.baidu.com/s/1FM7XG_HQT0G62RP7HaNBpw
提取码:nmkl

软件环境
软件版本
操作系统CentOS7.x_x64 (mini)
容器引擎Docker CE 19
KubernetesKubernetes v1.22
服务器整体规划
角色IP组件
k8s-master1192.168.31.71kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker,etcd,nginx,keepalived
k8s-master2192.168.31.74kube-apiserver,kube-controller-manager,kube-scheduler,kubelet,kube-proxy,docker,nginx,keepalived
k8s-node1192.168.31.72kubelet,kube-proxy,docker,etcd
k8s-node2192.168.31.73kubelet,kube-proxy,docker,etcd
负载均衡器IP192.168.31.88 (VIP)
组件架构图

img

单 Master 服务器规划

先搭建单节点的 Master 组件,然后在最后进行扩展,进行高可用配置

角色IP组件
k8s-master192.168.31.71kube-apiserver,kube-controller-manager,kube-scheduler,etcd
k8s-node1192.168.31.72kubelet,kube-proxy,docker,etcd
k8s-node2192.168.31.73kubelet,kube-proxy,docker,etcd

1.3 操作系统初始化配置

# 关闭防火墙 
$ systemctl stop firewalld 
$ systemctl disable firewalld 
 
# 关闭selinux 
$ sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
$ setenforce 0  # 临时 
 
# 关闭swap 
$ swapoff -a  # 临时 
$ sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久
 
# 根据规划设置主机名 
$ hostnamectl set-hostname <hostname> 
 
# 在master添加hosts 
$ cat >> /etc/hosts << EOF 
192.168.31.71 k8s-master1 
192.168.31.72 k8s-node1 
192.168.31.73 k8s-node2 
EOF 
 
# 将桥接的IPv4流量传递到iptables的链 
$ 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 
 
# 时间同步,这里简单通过 ntpdate 同步时间了,也可以选择通过 chrony 同步时间
$ yum install ntpdate -y 
$ ntpdate time.windows.com

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-1192.168.31.71
etcd-2192.168.31.72
etcd-3192.168.31.73

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(生产环境中一定使用单独服务器进行构建,并且最好使用 SSD 硬盘进行数据存储)

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 Master1 节点

# 软件已经存放在文章开头处提供的软件包中
$ 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

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": {
      "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 -
# 会生成 ca.pem 和 ca-key.pem 文件

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": [
    "192.168.31.71",
    "192.168.31.72",
    "192.168.31.73"
    ],
    "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
# 会生成 server.pem 和 server-key.pem 文件

2.3 从 Github 下载二进制文件

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

在 master1 节点操作

# 创建工作目录并解压二进制包
$ mkdir /opt/etcd/{bin,cfg,ssl} -p
$ tar zxvf etcd-v3.4.9-linux-amd64.tar.gz
$ mv etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

# 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://192.168.31.71:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
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_PEERURLS: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_INITIALCLUSTER_TOKEN:集群Token
# •ETCD_INITIALCLUSTER_STATE:加入集群的当前状态,new是新集群,existing表示加入已有集群

# 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

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

# 启动并设置开机启动 (注意,需要与其它两个节点的 etcd 同时启动,才可以,不会回阻塞等待其它节点启动)
$ systemctl daemon-reload
$ systemctl start etcd
$ systemctl enable etcd

# 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/ [email protected]:/opt/
$ scp /usr/lib/systemd/system/etcd.service [email protected]:/usr/lib/systemd/system/
$ scp -r /opt/etcd/ [email protected]:/opt/
$ scp /usr/lib/systemd/system/etcd.service [email protected]:/usr/lib/systemd/system/

在 node1 node2 节点操作

# 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
$ vi /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://192.168.31.71:2380"   # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.71:2379" # 修改此处为当前服务器IP

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.71:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.71:2379" # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.31.71:2380,etcd-2=https://192.168.31.72:2380,etcd-3=https://192.168.31.73:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

# 最后启动 etcd 并设置开机启动,同上

任意一节点

$ 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://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379" endpoint health --write-out=table

+----------------------------+--------+-------------+-------+
|          ENDPOINT    | HEALTH |    TOOK     | ERROR |
+----------------------------+--------+-------------+-------+
| https://192.168.31.71:2379 |   true | 10.301506ms |    |
| https://192.168.31.73:2379 |   true | 12.87467ms |     |
| https://192.168.31.72:2379 |   true | 13.225954ms |    |
+----------------------------+--------+-------------+-------+

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、安装 Docker

这里使用 Docker 作为容器引擎,也可以换成别的,例如 containerd

下载地址:https://download.docker.com/linux/static/stable/x86_64/docker-19.03.9.tgz

以下在所有节点操作。这里采用二进制安装,用 yum 安装也一样。

所有节点操作

# 解压二进制包
$ tar zxvf docker-19.03.9.tgz
$ mv docker/* /usr/bin

# systemd 管理 docker
$ cat > /usr/lib/systemd/system/docker.service << EOF
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target

[Service]
Type=notify
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TimeoutStartSec=0
Delegate=yes
KillMode=process
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s

[Install]
WantedBy=multi-user.target
EOF

# 创建配置文件
$ mkdir /etc/docker
$ cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF

# 启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start docker
$ systemctl enable docker

四、部署Master Node

4.1 生成 kube-apiserver 证书

在 Master1 节点执行

# 自签证书颁发机构(CA)

$ cd ~/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 -
# 会生成 ca.pem 和 ca-key.pem 文件

# 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",
      "127.0.0.1",
      "192.168.31.71",
      "192.168.31.72",
      "192.168.31.73",
"192.168.31.74",
      "192.168.31.88",
      "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
# 会生成 server.pem 和 server-key.pem 文件

4.2 从 Github 下载二进制文件

下载地址: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.20.md

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

4.3 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/

4.4 部署 kube-apiserver

# 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://192.168.31.71:2379,https://192.168.31.72:2379,https://192.168.31.73:2379 \\
--bind-address=192.168.31.71 \\
--secure-port=6443 \\
--advertise-address=192.168.31.71 \\
--allow-privileged=true \\
--service-cluster-ip-range=10.0.0.0/24 \\
--enable-admission-plugins=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 \\
--service-account-issuer=api \\
--service-account-signing-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 \\
--requestheader-client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--proxy-client-cert-file=/opt/kubernetes/ssl/server.pem \\
--proxy-client-key-file=/opt/kubernetes/ssl/server-key.pem \\
--requestheader-allowed-names=kubernetes \\
--requestheader-extra-headers-prefix=X-Remote-Extra- \\
--requestheader-group-headers=X-Remote-Group \\
--requestheader-username-headers=X-Remote-User \\
--enable-aggregator-routing=true \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF
# •--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
# •1.20版本必须加的参数:--service-account-issuer,--service-account-signing-key-file
# •--etcd-xxxfile:连接Etcd集群证书
# •--audit-log-xxx:审计日志
# •启动聚合层相关配置:--requestheader-client-ca-file,--proxy-client-cert-file,--proxy-client-key-file,--requestheader-allowed-names,--requestheader-extra-headers-prefix,--requestheader-group-headers,--requestheader-username-headers,--enable-aggregator-routing

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

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

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。

TLS bootstraping 工作流程

img

# 创建上述配置文件中 token 文件
$ cat > /opt/kubernetes/cfg/token.csv << EOF
c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF

格式:token,用户名,UID,用户组,token 也可自行生成替换

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

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

启动并设置开机启动

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

4.5 部署 kube-controller-manager

# 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 \\
--kubeconfig=/opt/kubernetes/cfg/kube-controller-manager.kubeconfig \\
--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 \\
--cluster-signing-duration=87600h0m0s"
EOF

# •--kubeconfig:连接apiserver配置文件
# •--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


# 生成 kubeconfig 文件, 生成 kube-controller-manager 证书
# 切换工作目录
$ cd ~/TLS/k8s

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

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

# 生成 kubeconfig 文件(以下是shell命令,直接在终端执行)
$ KUBE_CONFIG="/opt/kubernetes/cfg/kube-controller-manager.kubeconfig"
$ KUBE_APISERVER="https://192.168.31.71:6443"

$ kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config set-credentials kube-controller-manager \
  --client-certificate=./kube-controller-manager.pem \
  --client-key=./kube-controller-manager-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-controller-manager \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

# 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

# 启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start kube-controller-manager
$ systemctl enable kube-controller-manager

4.6 部署 kube-scheduler

# 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 \\
--kubeconfig=/opt/kubernetes/cfg/kube-scheduler.kubeconfig \\
--bind-address=127.0.0.1"
EOF

# •--kubeconfig:连接apiserver配置文件
# •--leader-elect:当该组件启动多个时,自动选举(HA)


# 生成 kubeconfig 文件, 生成 kube-scheduler 证书
# 切换工作目录
$ cd ~/TLS/k8s

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

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

# 生成 kubeconfig 文件
$ KUBE_CONFIG="/opt/kubernetes/cfg/kube-scheduler.kubeconfig"
$ KUBE_APISERVER="https://192.168.31.71:6443"

$ kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config set-credentials kube-scheduler \
  --client-certificate=./kube-scheduler.pem \
  --client-key=./kube-scheduler-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-scheduler \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

# 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

# 启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start kube-scheduler
$ systemctl enable kube-scheduler

查看集群状态

# 生成 kubectl 连接集群的证书
$ cat > admin-csr.json <<EOF
{
  "CN": "admin",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing",
      "O": "system:masters",
      "OU": "System"
    }
  ]
}
EOF

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

# 生成 kubeconfig 文件
$ mkdir /root/.kube

$ KUBE_CONFIG="/root/.kube/config"
$ KUBE_APISERVER="https://192.168.31.71:6443"

$ kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config set-credentials cluster-admin \
  --client-certificate=./admin.pem \
  --client-key=./admin-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config set-context default \
  --cluster=kubernetes \
  --user=cluster-admin \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

# 通过 kubectl 工具查看当前集群组件状态
$ kubectl get cs
NAME                STATUS    MESSAGE             ERROR
scheduler             Healthy   ok                  
controller-manager       Healthy   ok                  
etcd-2               Healthy   {"health":"true"}   
etcd-1               Healthy   {"health":"true"}   
etcd-0               Healthy   {"health":"true"}  
# 如上输出说明 Master 节点组件运行正常

# 授权 kubelet-bootstrap 用户允许请求证书
$ kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap

五、部署 Worker Node

下面还是在 Master Node 上操作,即同时作为 Worker Node

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

# 从 master 节点拷贝
$ cd kubernetes/server/bin
$ cp kubelet kube-proxy /opt/kubernetes/bin   # 本地拷贝

部署 kubelet

# 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-master1 \\
--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=wangyanglinux/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

# 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

# 生成 kubelet 初次加入集群引导 kubeconfig 文件
$ KUBE_CONFIG="/opt/kubernetes/cfg/bootstrap.kubeconfig"
$ KUBE_APISERVER="https://192.168.31.71:6443" # apiserver IP:PORT
$ TOKEN="c47ffb939f5ca36231d9e3121a252940" # 与token.csv里保持一致

# 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=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config set-credentials "kubelet-bootstrap" \
  --token=${TOKEN} \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config set-context default \
  --cluster=kubernetes \
  --user="kubelet-bootstrap" \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

# 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

# 启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start kubelet
$ systemctl enable kubelet

# 批准 kubelet 证书申请并加入集群
## 查看 kubelet 证书请求
$ kubectl get csr
    NAME  REQUESTOR           CONDITION
    node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A   6m3s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 批准申请
$ kubectl certificate approve node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A

# 查看节点
$ kubectl get node
    NAME         STATUS     ROLES    AGE   VERSION
    k8s-master1   NotReady   <none>   7s    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

部署kube-proxy

# 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

# 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-master1
clusterCIDR: 10.244.0.0/16
EOF

# 生成 kube-proxy.kubeconfig 文件
## 切换工作目录
$ 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

# 生成 kubeconfig 文件:
$ KUBE_CONFIG="/opt/kubernetes/cfg/kube-proxy.kubeconfig"
$ KUBE_APISERVER="https://192.168.31.71:6443"

$ kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config set-credentials kube-proxy \
  --client-certificate=./kube-proxy.pem \
  --client-key=./kube-proxy-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-proxy \
  --kubeconfig=${KUBE_CONFIG}
$ kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

# 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

# 启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start kube-proxy
$ systemctl enable kube-proxy

部署网络组件

Calico 是一个纯三层的数据中心网络方案,是目前 Kubernetes 主流的网络方案

# 部署 Calico
$ kubectl apply -f calico.yaml
$ kubectl get pods -n kube-system

# 等 Calico Pod 都 Running,节点也会准备就绪
$ kubectl get node
    NAME         STATUS   ROLES    AGE   VERSION
    k8s-master   Ready    <none>   37m   v1.22.4

授权 apiserver 访问 kubelet

应用场景:例如 kubectl logs

$ 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

新增加 Worker Node

# 拷贝已部署好的 Node 相关文件到新节点, 在 Master 节点将 Worker Node 涉及文件拷贝到新节点 192.168.31.72/73
$ scp -r /opt/kubernetes [email protected]:/opt/

$ scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service [email protected]:/usr/lib/systemd/system

$ scp /opt/kubernetes/ssl/ca.pem [email protected]:/opt/kubernetes/ssl

# 删除 kubelet 证书和 kubeconfig 文件
$ rm -f /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

# 修改主机名
$ vi /opt/kubernetes/cfg/kubelet.conf
    --hostname-override=k8s-node1

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

# 启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start kubelet kube-proxy
$ systemctl enable kubelet kube-proxy

# 在 Master 上批准新 Node kubelet 证书申请
# 查看证书请求
$ kubectl get csr
    NAME           AGE   SIGNERNAME                    REQUESTOR           CONDITION
    node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro   89s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending
# 授权请求
$ kubectl certificate approve node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro

# 查看 Node 状态
$ kubectl get node
    NAME       STATUS   ROLES    AGE     VERSION
    k8s-master1   Ready    <none>   47m     v1.22.4
    k8s-node1    Ready    <none>   6m49s   v1.22.4
# Node2(192.168.31.73 )节点同上。记得修改主机名!

六、部署 Dashboard 和 CoreDNS

部署 Dashboard

# yaml 文件在文章头部提供的软件包中
$ kubectl apply -f kubernetes-dashboard.yaml
# 查看部署
$ kubectl get pods,svc -n kubernetes-dashboard

# 访问地址:https://NodeIP:30001
# 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

部署CoreDNS

# CoreDNS 用于集群内部 Service 名称解析
$ kubectl apply -f coredns.yaml 
 
$ kubectl get pods -n kube-system  
    NAME                          READY   STATUS    RESTARTS   AGE 
    coredns-5ffbfd976d-j6shb      1/1     Running   0          32s
    
# 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

七、扩容多Master(高可用架构)

Kubernetes 作为容器集群系统,通过健康检查+重启策略实现了 Pod 故障自我修复能力,通过调度算法实现将 Pod 分布式部署,并保持预期副本数,根据 Node 失效状态自动在其他 Node 拉起 Pod,实现了应用层的高可用性。

针对 Kubernetes 集群,高可用性还应包含以下两个层面的考虑:Etcd 数据库的高可用性和 Kubernetes Master 组件的高可用性。 而 Etcd 我们已经采用 3 个节点组建集群实现高可用,本节将对 Master 节点高可用进行说明和实施。

Master 节点扮演着总控中心的角色,通过不断与工作节点上的 Kubelet 和 kube-proxy 进行通信来维护整个集群的健康工作状态。如果 Master 节点故障,将无法使用 kubectl 工具或者 API 做任何集群管理。

Master 节点主要有三个服务 kube-apiserver、kube-controller-manager 和 kube-scheduler,其中 kube-controller-manager 和 kube-scheduler 组件自身通过选择机制已经实现了高可用,所以 Master 高可用主要针对 kube-apiserver 组件,而该组件是以 HTTP API 提供服务,因此对他高可用与 Web 服务器类似,增加负载均衡器对其负载均衡即可,并且可水平扩容。

多 Master 架构图:

img

部署 Master2 Node

现在需要再增加一台新服务器,作为Master2 Node,IP是192.168.31.74。

为了节省资源你也可以将之前部署好的Worker Node1复用为Master2 Node角色(即部署Master组件)

Master2 与已部署的Master1所有操作一致。所以我们只需将Master1所有K8s文件拷贝过来,再修改下服务器IP和主机名启动即可。

# 安装 Docker
$ scp /usr/bin/docker* [email protected]:/usr/bin
$ scp /usr/bin/runc [email protected]:/usr/bin
$ scp /usr/bin/containerd* [email protected]:/usr/bin
$ scp /usr/lib/systemd/system/docker.service [email protected]:/usr/lib/systemd/system
$ scp -r /etc/docker [email protected]:/etc

# 在Master2启动Docker
$ systemctl daemon-reload
$ systemctl start docker
$ systemctl enable docker

# 创建 etcd 证书目录
## 在 Master2 创建 etcd 证书目录
$ mkdir -p /opt/etcd/ssl

# 拷贝文件(Master1操作)
## 拷贝 Master1 上所有 K8s 文件和 etcd 证书到 Master2
$ scp -r /opt/kubernetes [email protected]:/opt
$ scp -r /opt/etcd/ssl [email protected]:/opt/etcd
$ scp /usr/lib/systemd/system/kube* [email protected]:/usr/lib/systemd/system
$ scp /usr/bin/kubectl  [email protected]:/usr/bin
$ scp -r ~/.kube [email protected]:~

# 删除证书文件
## 删除 kubelet 证书和 kubeconfig 文件
$ rm -f /opt/kubernetes/cfg/kubelet.kubeconfig 
$ rm -f /opt/kubernetes/ssl/kubelet*

# 修改配置文件 IP 和主机名
## 修改 apiserver、kubelet 和 kube-proxy 配置文件为本地 IP
$ vi /opt/kubernetes/cfg/kube-apiserver.conf 
    ...
    --bind-address=192.168.31.74 \
    --advertise-address=192.168.31.74 \
    ...

$ vi /opt/kubernetes/cfg/kube-controller-manager.kubeconfig
    server: https://192.168.31.74:6443

$ vi /opt/kubernetes/cfg/kube-scheduler.kubeconfig
    server: https://192.168.31.74:6443

$ vi /opt/kubernetes/cfg/kubelet.conf
    --hostname-override=k8s-master2

$ vi /opt/kubernetes/cfg/kube-proxy-config.yml
    hostnameOverride: k8s-master2

$ vi ~/.kube/config
    ...
    server: https://192.168.31.74:6443
    
# 启动设置开机启动
$ systemctl daemon-reload
$ systemctl start kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy
$ systemctl enable kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy

# 查看集群状态
$ kubectl get cs
    NAME                STATUS    MESSAGE             ERROR
    scheduler             Healthy   ok                  
    controller-manager       Healthy   ok                  
    etcd-1               Healthy   {"health":"true"}   
    etcd-2               Healthy   {"health":"true"}   
    etcd-0               Healthy   {"health":"true"}
    
# 批准 kubelet 证书申请
# 查看证书请求
$ kubectl get csr
    NAME                      AGE          SIGNERNAME          REQUESTOR           CONDITION
    node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU   85m   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending
# 授权请求
$ kubectl certificate approve node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU

# 查看Node
$ kubectl get node
    NAME        STATUS   ROLES    AGE   VERSION
    k8s-master1    Ready    <none>   34h   v1.22.4
    k8s-master2    Ready    <none>   2m   v1.22.4
    k8s-node1     Ready    <none>   33h   v1.22.4
    k8s-node2     Ready    <none>   33h   v1.22.4

部署 Nginx+Keepalived 高可用负载均衡器

kube-apiserver 高可用架构图

img

• Nginx 是一个主流 Web 服务和反向代理服务器,这里用四层实现对 apiserver 实现负载均衡。

• Keepalived 是一个主流高可用软件,基于 VIP 绑定实现服务器双机热备,在上述拓扑中,Keepalived 主要根据 Nginx 运行状态判断是否需要故障转移( 漂移VIP ),例如当 Nginx 主节点挂掉,VIP 会自动绑定在 Nginx 备节点,从而保证VIP一直可用,实现 Nginx 高可用。

注1:为了节省机器,这里与K8s Master节点机器复用。也可以独立于k8s集群之外部署,只要nginx与apiserver能通信就行。

注2:如果你是在公有云上,一般都不支持keepalived,那么你可以直接用它们的负载均衡器产品,直接负载均衡多台Master kube-apiserver,架构与上面一样。

在两台Master节点操作。

# 安装软件包(主/备)
$ yum install epel-release -y
$ yum install nginx keepalived nginx-mod-stream -y

# Nginx 配置文件(主/备一样)
$ cat > /etc/nginx/nginx.conf << "EOF"
# 加载stream模块
load_module /usr/lib64/nginx/modules/ngx_stream_module.so;
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

include /usr/share/nginx/modules/*.conf;

events {
    worker_connections 1024;
}

# 四层负载均衡,为两台Master apiserver组件提供负载均衡
stream {

    log_format  main  '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent';

    access_log  /var/log/nginx/k8s-access.log  main;

    upstream k8s-apiserver {
       server 192.168.31.71:6443;   # Master1 APISERVER IP:PORT
       server 192.168.31.74:6443;   # Master2 APISERVER IP:PORT
    }
    
    server {
       listen 16443; # 由于nginx与master节点复用,这个监听端口不能是6443,否则会冲突
       proxy_pass k8s-apiserver;
    }
}

http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;

    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;

    server {
        listen       80 default_server;
        server_name  _;
        location / {
        }
    }
}
EOF
# keepalived 配置文件(Nginx Master)
$ cat > /etc/keepalived/keepalived.conf << EOF
global_defs { 
   notification_email { 
     [email protected] 
     [email protected] 
     [email protected] 
   } 
   notification_email_from [email protected]  
   smtp_server 127.0.0.1 
   smtp_connect_timeout 30 
   router_id NGINX_MASTER
} 

vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}

vrrp_instance VI_1 { 
    state MASTER 
    interface ens33  # 修改为实际网卡名
    virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 
    priority 100    # 优先级,备服务器设置 90 
    advert_int 1    # 指定VRRP 心跳包通告间隔时间,默认1秒 
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    # 虚拟IP
    virtual_ipaddress { 
        192.168.31.88/24
    } 
    track_script {
        check_nginx
    } 
}
EOF

# •vrrp_script:指定检查nginx工作状态脚本(根据nginx状态判断是否故障转移)
# •virtual_ipaddress:虚拟IP(VIP)

准备上述配置文件中检查 nginx 运行状态的脚本

$ cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")

if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF

$ chmod +x /etc/keepalived/check_nginx.sh

keepalived 配置文件(Nginx Backup)

cat > /etc/keepalived/keepalived.conf << EOF
global_defs { 
   notification_email { 
     [email protected] 
     [email protected] 
     [email protected] 
   } 
   notification_email_from [email protected]  
   smtp_server 127.0.0.1 
   smtp_connect_timeout 30 
   router_id NGINX_BACKUP
} 

vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}
vrrp_instance VI_1 { 
    state BACKUP 
    interface ens33
    virtual_router_id 51 # VRRP 路由 ID实例,每个实例是唯一的 
    priority 90
    advert_int 1
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    virtual_ipaddress { 
        192.168.31.88/24
    } 
    track_script {
        check_nginx
    } 
}
EOF

准备上述配置文件中检查 nginx 运行状态的脚本

$ cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ss -antp |grep 16443 |egrep -cv "grep|$$")

if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF

$ chmod +x /etc/keepalived/check_nginx.sh

注:keepalived 根据脚本返回状态码(0为工作正常,非0不正常)判断是否故障转移

# 启动并设置开机启动
$ systemctl daemon-reload
$ systemctl start nginx keepalived
$ systemctl enable nginx keepalived

# 查看 keepalived 工作状态
$ ip addr
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
           valid_lft forever preferred_lft forever
        inet6 ::1/128 scope host 
           valid_lft forever preferred_lft forever
    2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
        link/ether 00:0c:29:04:f7:2c brd ff:ff:ff:ff:ff:ff
        inet 192.168.31.80/24 brd 192.168.31.255 scope global noprefixroute ens33
           valid_lft forever preferred_lft forever
        inet 192.168.31.88/24 scope global secondary ens33
           valid_lft forever preferred_lft forever
        inet6 fe80::20c:29ff:fe04:f72c/64 scope link 
           valid_lft forever preferred_lft forever
       
# 访问负载均衡器测试
## 找 K8s 集群中任意一个节点,使用 curl 查看 K8s 版本测试,使用 VIP 访问 
$ curl -k https://192.168.31.88:16443/version
    {
      "major": "1",
      "minor": "20",
      "gitVersion": "v1.22.4",
      "gitCommit": "e87da0bd6e03ec3fea7933c4b5263d151aafd07c",
      "gitTreeState": "clean",
      "buildDate": "2021-02-18T16:03:00Z",
      "goVersion": "go1.15.8",
      "compiler": "gc",
      "platform": "linux/amd64"
    }
    
# 通过查看 Nginx 日志也可以看到转发 apiserver IP
$ tail /var/log/nginx/k8s-access.log -f
    192.168.31.71 192.168.31.71:6443 - [02/Apr/2021:19:17:57 +0800] 200 423
    192.168.31.71 192.168.31.72:6443 - [02/Apr/2021:19:18:50 +0800] 200 423

修改所有 Worker Node 连接 LB VIP

试想下,虽然我们增加了Master2 Node和负载均衡器,但是我们是从单Master架构扩容的,也就是说目前所有的Worker Node组件连接都还是Master1 Node,如果不改为连接VIP走负载均衡器,那么Master还是单点故障。

因此接下来就是要改所有Worker Node(kubectl get node命令查看到的节点)组件配置文件,由原来192.168.31.71修改为192.168.31.88(VIP)。

在所有Worker Node执行:

$ sed -i 's#192.168.31.71:6443#192.168.31.88:16443#' /opt/kubernetes/cfg/*

$ systemctl restart kubelet kube-proxy

检查节点状态

$ kubectl get node 
    NAME         STATUS   ROLES    AGE   VERSION 
    k8s-master1   Ready    <none>   32d   v1.22.4 
    k8s-master2   Ready    <none>   10m   v1.22.4 
    k8s-node1    Ready    <none>   31d   v1.22.4 
    k8s-node2    Ready    <none>   31d   v1.22.4
0

评论区