Kubernetes the hard way

kubernetes
Author

曳影

Published

November 19, 2022

服务器说明

  1. Kubernets Version
  • v1.22.15
  1. 节点要求
  • 节点数 >= 3台
  • CPUs >= 2
  • Memory >= 2G
  1. 修改时区 有的系统时区不匹配,需要修改
timedatectl set-timezone Asia/Shanghai
  1. 环境说明
系统类型 IP地址 节点角色 CPU Memory Hostname
CentOS-7.9 192.168.200.11 master >=2 >=2G cluster1
CentOS-7.9 192.168.200.22 master,worker >=2 >=2G custer2
CentOS-7.9 192.168.200.33 worker >=2 >=2G cluster3
  1. 使用Vagrant搭建虚拟机节点
  • Vagrant: latest
  • VirtualBox: 7.0
  • vagrant-vbguest: 0.21 (挂载hostguest同步目录)
vagrant plugin install vagrant-vbguest --plugin-version 0.21

Vagrantfile配置文件如下:

# -*- mode: ruby -*-
# vi: set ft=ruby :

nodes = [
  {
     => "cluster1",
     => "192.168.200.11",
     => "4096",
     => "2"
  },
  {
     => "cluster2",
     => "192.168.200.22",
     => "4096",
     => "2"
  },
  {
     => "cluster3",
     => "192.168.200.33",
     => "4096",
     => "2"
  },
]


Vagrant.configure("2") do |config|
  # Every Vagrant development environment requires a box.
  config.vm.box = "centos/7"

  nodes.each do |opts|
    config.vm.define opts[] do |config|
      config.vm.hostname = opts[]

      config.vm.provider "virtualbox" do |v|
        v.customize ["modifyvm", , "--memory", opts[]]
        v.customize ["modifyvm", , "--cpus", opts[]]
      end

      #config.ssh.username = "root"
      #config.ssh.private_key_path = "/Users/jinpeng.d/.ssh/id_rsa"
      config.vm.synced_folder "../share", "/vagrant_data"

      config.vm.network , opts[]
      config.vm.synced_folder "../share", "/vagrant_data"

    end
  end
end

系统设置(所有节点)

  1. 所有操作需要root权限
  2. hostname (/etc/hosts)
  3. 安装依赖包
yum update -y
yum install -y socat conntrack ipvsadm ipset jq sysstat curl iptables libseccomp yum-utils
  1. 关闭防火墙,selinux, swap,重置 iptables
# 1. 关闭selinux
setenforce 0
sed -i '/SELINUX/s/enforcing/disabled/' /etc/selinux/config
# 2. 关闭防火墙
systemctl stop firewalld && systemctl disable firewalld

# 3. 设置ipttables规则
iptables -F && iptables -X && iptables -F -t nat && iptables -X -t nat && iptables -P FORWARD ACCEPT

# 4. 关闭swap
vi /etc/fstab
# 永久禁用注释掉swap
#/swapfile none swap defaults 0 0
# 临时禁用
swapoff -a
# 这里两者都用,临时修改可以即时生效,不用重启,永久禁用防止重启后不生效

# 5. 关闭dnsmasq(否则无法解析域名)
service dnsmasq stop && systemctl disable dnsmasq
  1. kubernetes参数设置
cat > /etc/sysctl.d/kubernetes.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_nonlocal_bind = 1
net.ipv4.ip_forward = 1
vm.swappiness = 0
vm.overcommit_memory = 1
EOF

# 生效文件
sysctl -p /etc/sysctl.d/kubernetes.conf
  1. 配置免密登录 选择其中一个节点,或者一个单独的机器生成ssh公秘钥对,把公钥放在k8s所有节点服务器上
# 生成公秘钥对, 如果没有可用的
ssh-keygen -t rsa

# 查看公钥内容
cat ~/.ssh/id_rsa.pub

# 每一台节点机器上配置
echo "<pubkey content>" >> ~/.ssh/authorized_keys
  1. 配置IP映射(每个节点)
cat > /etc/hosts <<EOF
192.168.200.11 cluster1
192.168.200.22 cluster2
192.168.200.33 cluster3
EOF
  1. 下载k8s组件包
export VERSION=v1.22.15

# 下载master节点组件
wget https://storage.googleapis.com/kubernetes-release/release/${VERSION}/bin/linux/amd64/kube-apiserver
wget https://storage.googleapis.com/kubernetes-release/release/${VERSION}/bin/linux/amd64/kube-controller-manager
wget https://storage.googleapis.com/kubernetes-release/release/${VERSION}/bin/linux/amd64/kube-scheduler
wget https://storage.googleapis.com/kubernetes-release/release/${VERSION}/bin/linux/amd64/kubectl

# 下载worker节点组件
wget https://storage.googleapis.com/kubernetes-release/release/${VERSION}/bin/linux/amd64/kube-proxy
wget https://storage.googleapis.com/kubernetes-release/release/${VERSION}/bin/linux/amd64/kubelet

# 下载etcd组件
wget https://github.com/etcd-io/etcd/releases/download/v3.4.10/etcd-v3.4.10-linux-amd64.tar.gz
tar -xvf etcd-v3.4.10-linux-amd64.tar.gz
mv etcd-v3.4.10-linux-amd64/etcd* .
rm -fr etcd-v3.4.10-linux-amd64*
  1. 分发软件包
# 把master相关组件分发到master节点
MASTERS=(cluster1 cluster2)
for instance in ${MASTERS[@]}; do
  scp kube-apiserver kube-controller-manager kube-scheduler kubectl root@${instance}:/usr/local/bin/
done

# 把worker先关组件分发到worker节点
WORKERS=(cluster2 cluster3)
for instance in ${WORKERS[@]}; do
  scp kubelet kube-proxy root@${instance}:/usr/local/bin/
done

# 把etcd组件分发到etcd节点
ETCDS=(cluster1 cluster2 cluster3)
for instance in ${ETCDS[@]}; do
  scp etcd etcdctl root@${instance}:/usr/local/bin/
done

生成证书

  1. 准备工作
  • 安装cfssl

    wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64 -O /usr/local/bin/cfssl
    wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64 -O /usr/local/bin/cfssljson
    chmod +x /usr/local/bin/cfssl*
  • kubernetes集群组件

    • 服务端组件:
      • kube-apiserver
      • kube-controller-manager
      • kube-scheduler
      • kubectl
      • container runtime(containerd)
    • 客户端组件:
      • kubelet
      • kube-proxy
      • container runtime(containerd)
  1. 生成根证书 根证书是集群所有节点共享的,只要创建一个CA证书,后续创建的所有证书都由它签名。 在可以登录到所有节点的控制台机器上创建pki目录存放证书
  • 根证书配置文件创建

    cat > ca-config.json <<EOF
    {
      "signing": {
        "default": {
          "expiry": "876000h"
        },
        "profiles": {
          "kubernetes": {
            "usages": ["signing", "key encipherment", "server auth", "client auth"],
            "expiry": "876000h"
          }
        }
      }
    }
    EOF
    
    cat > ca-csr.json <<EOF
    {
      "CN": "Kubernetes",
      "key": {
        "algo": "rsa",
        "size": 2048
      },
      "names": [
        {
          "C": "US",
          "L": "Portland",
          "O": "Kubernetes",
          "OU": "CA",
          "ST": "Oregon"
        }
      ]
    }
    EOF
  • 生成证书和密钥

生成证书和私钥, ca.pem是证书, ca-key.pem是证书私钥 bash cfssl gencert -initca ca-csr.json | cfssljson -bare ca 输出文件:

  • ca.pem
  • ca.csr
  • ca-key.pem
  1. admin客户端证书
  • admin客户端证书配置文件

    cat > admin-csr.json <<EOF
    {
      "CN": "admin",
      "key": {
        "algo": "rsa",
        "size": 2048
      },
      "names": [
        {
          "C": "CN",
          "ST": "BeiJing",
          "L": "BeiJing",
          "O": "system:masters",
          "OU": "seven"
        }
      ]
    }
    EOF
  • 生成admin客户端证书和私钥(基于根证书和私钥以及证书配置文件)

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

    输出文件:

    • admin.csr
    • admin.pem
    • admin-key.pem
  1. kubelet客户端证书 kubernetes使用一种称为Node Authorizer的专用授权模式来授权kubernetes发出的API请求。 kubelet使用将其标识为system:nodes组中的凭据,其用户名为system: node:nodeName, 接下来给每个Worker节点生成证书。
  • 生成kubelet客户端证书配置文件

    • 设置Worker节点列表
    WORKERS=(cluster2 cluster3)
    WORKER_IPS=(192.168.200.22 192.168.200.33)
    for ((i=0;i<${#WORKERS[@]};i++)); do
      cat > ${WORKERS[$i]}-csr.json <<EOF
      {
        "CN": "system:node:${WORKERS[$i]}",
        "key": {
          "algo": "rsa",
          "size": 2048
        },
        "names": [
          {
            "C": "CN",
            "L": "Beijing",
            "O": "system:nodes",
            "OU": "seven",
            "ST": "Beijing"
          }
        ]
      }
    EOF
    done
  • 生成kubelet客户端证书和密钥

    for ((i=0;i<${#WORKERS[@]};i++)); do
      cfssl gencert \
        -ca=ca.pem \
        -ca-key=ca-key.pem \
        -config=ca-config.json \
        -hostname=${WORKERS[$i]},${WORKER_IPS[$i]} \
        -profile=kubernetes \
        ${WORKERS[$i]}-csr.json | cfssljson -bare ${WORKERS[$i]}
    done

    输出文件:

    • {worker-node-name}.csr
    • {worker-node-name}.pem
    • {worker-node-name}-key.pem
  1. kube-controller-manager客户端证书
  • kube-controller-manager客户端证书配置文件
cat > kube-controller-manager-csr.json <<EOF
{
    "CN": "system:kube-controller-manager",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
      {
        "C": "CN",
        "ST": "BeiJing",
        "L": "BeiJing",
        "O": "system:kube-controller-manager",
        "OU": "seven"
      }
    ]
}
EOF
  • 生成kube-controller-manager客户端证书
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

输出文件: + kube-controller-manager.csr + kube-controller-manager.pem + kube-controller-manager-key.pem

  1. kube-proxy客户端证书
  • kube-proxy客户端证书配置文件

    cat > kube-proxy-csr.json <<EOF
    {
      "CN": "system:kube-proxy",
      "key": {
        "algo": "rsa",
        "size": 2048
      },
      "names": [
        {
          "C": "CN",
          "ST": "BeiJing",
          "L": "BeiJing",
          "O": "k8s",
          "OU": "seven"
        }
      ]
    }
    EOF
  • 生成kube-proxy客户端证书

    cfssl gencert \
    -ca=ca.pem \
    -ca-key=ca-key.pem \
    -config=ca-config.json \
    -profile=kubernetes \
    kube-proxy-csr.json | cfssljson -bare kube-proxy

    输出文件:

    • kube-proxy.csr
    • kube-proxy.pem
    • kube-proxy-key.pem
  1. kube-scheduler客户端证书
  • kube-scheduler客户端证书配置

    cat > kube-scheduler-csr.json <<EOF
    {
        "CN": "system:kube-scheduler",
        "key": {
            "algo": "rsa",
            "size": 2048
        },
        "names": [
          {
            "C": "CN",
            "ST": "BeiJing",
            "L": "BeiJing",
            "O": "system:kube-scheduler",
            "OU": "seven"
          }
        ]
    }
    EOF
  • 生成kube-scheduler客户端证书

    cfssl gencert \
    -ca=ca.pem \
    -ca-key=ca-key.pem \
    -config=ca-config.json \
    -profile=kubernetes \
    kube-scheduler-csr.json | cfssljson -bare kube-scheduler

    输出文件:

    • kube-scheduler.csr
    • kube-scheduler.pem
    • kube-scheduler-key.pem
  1. kube-apiserver服务端证书
  • kube-apiserver服务端证书配置

    cat > kubernetes-csr.json <<EOF
    {
      "CN": "kubernetes",
      "key": {
        "algo": "rsa",
        "size": 2048
      },
      "names": [
        {
          "C": "CN",
          "ST": "BeiJing",
          "L": "BeiJing",
          "O": "k8s",
          "OU": "seven"
        }
      ]
    }
    EOF
  • 生成kube-apiserver服务端证书 服务端证书与客户端证书不同:

    • 客户端证书需要通过一个名字或者IP去访问服务端,所以证书需要包含客户端所访问的名字或IP,用以客户端验证
    • 指定可能作为master的节点服务地址
    • apiserver的 service ip地址(一般是svc网段的第一个ip)
    • 所有master内网IP和公网IP,逗号分割,(可以把所有节点写上,防止变换master节点)
    KUBERNETES_SVC_IP="10.233.0.1"
    MASTER_IPS="192.168.200.11,192.168.200.22,192.168.200.33"
    cfssl gencert \
    -ca=ca.pem \
    -ca-key=ca-key.pem \
    -config=ca-config.json \
    -hostname=${KUBERNETES_SVC_IP},${MASTER_IPS},127.0.0.1,kubernetes,kubernetes.default,kubernetes.default.svc,kubernetes.default.svc.cluster,kubernetes.svc.cluster.local \
    -profile=kubernetes \
    kubernetes-csr.json | cfssljson -bare kubernetes

    输出文件:

    • kubernetes.csr
    • kubernetes.pem
    • kubernetes-key.pem
  1. Service Account证书
  • 配置文件

    cat > service-account-csr.json <<EOF
    {
      "CN": "service-accounts",
      "key": {
        "algo": "rsa",
        "size": 2048
      },
      "names": [
        {
          "C": "CN",
          "ST": "BeiJing",
          "L": "BeiJing",
          "O": "k8s",
          "OU": "seven"
        }
      ]
    }
    EOF
  • 生成证书

    cfssl gencert \
    -ca=ca.pem \
    -ca-key=ca-key.pem \
    -config=ca-config.json \
    -profile=kubernetes \
    service-account-csr.json | cfssljson -bare service-account

    输出文件:

    • service-account.csr
    • service-account.pem
    • service-account-key.pem
  1. proxy-client证书
  • 配置文件

    cat > proxy-client-csr.json <<EOF
    {
      "CN": "aggregator",
      "key": {
        "algo": "rsa",
        "size": 2048
      },
      "names": [
        {
          "C": "CN",
          "ST": "BeiJing",
          "L": "BeiJing",
          "O": "k8s",
          "OU": "seven"
        }
      ]
    }
    EOF
  • 生成证书

    cfssl gencert \
    -ca=ca.pem \
    -ca-key=ca-key.pem \
    -config=ca-config.json \
    -profile=kubernetes \
    proxy-client-csr.json | cfssljson -bare proxy-client

    输出文件:

    • proxy-client.csr
    • proxy-client.pem
    • proxy-client-key.pem
  1. 分发客户端,服务端证书
  • 分发Worker节点需要的证书和私钥
    • 每个Worker节点证书和密钥
    WORKERS=("cluster2" "cluster3")
    for instance in ${WORKERS[@]}; do
      scp ca.pem ${instance}-key.pem ${instance}.pem root@${instance}:~/
    done
  • 分发Master节点需要的证书和私钥
    • 根证书和密钥(ca*.pem)
    • kube-apiserver证书和密钥(kubenetes*.pem)
    • service-account证书和密钥(service-account*.pem)
    • proxy-client证书和密钥(proxy-client*.pem)
    MASTER_IPS=(cluster1 cluster2)
    for instance in ${MASTER_IPS[@]}; do
      scp ca.pem ca-key.pem kubernetes-key.pem kubernetes.pem \
        service-account-key.pem service-account.pem proxy-client.pem proxy-client-key.pem root@${instance}:~/
    done

kubernetes各组件的认证配置

kubernetes的认证配置文件,称为kubeconfigs,用于让kubernetes的客户端定位 kube-apiserver并通过apiserver的安全认证。

  • controller-manager
  • kubelet
  • kube-proxy
  • scheduler
  • admin user
  1. kubelet生成kubeconfigs(每个Worker节点)
WORKERS=("cluster2" "cluster3")
for instance in ${WORKERS[@]}; do
  kubectl config set-cluster kubernetes \
    --certificate-authority=ca.pem \
    --embed-certs=true \
    --server=https://127.0.0.1:6443 \
    --kubeconfig=${instance}.kubeconfig

  kubectl config set-credentials system:node:${instance} \
    --client-certificate=${instance}.pem \
    --client-key=${instance}-key.pem \
    --embed-certs=true \
    --kubeconfig=${instance}.kubeconfig

  kubectl config set-context default \
    --cluster=kubernetes \
    --user=system:node:${instance} \
    --kubeconfig=${instance}.kubeconfig

  kubectl config use-context default --kubeconfig=${instance}.kubeconfig
done
  1. kube-proxy生成kubeconfigs
kubectl config set-cluster kubernetes \
    --certificate-authority=ca.pem \
    --embed-certs=true \
    --server=https://127.0.0.1:6443 \
    --kubeconfig=kube-proxy.kubeconfig

kubectl config set-credentials system: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=system:kube-proxy \
  --kubeconfig=kube-proxy.kubeconfig

kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
  1. kube-controller-manager生成kubeconfigs
kubectl config set-cluster kubernetes \
  --certificate-authority=ca.pem \
  --embed-certs=true \
  --server=https://127.0.0.1:6443 \
  --kubeconfig=kube-controller-manager.kubeconfig

kubectl config set-credentials system:kube-controller-manager \
  --client-certificate=kube-controller-manager.pem \
  --client-key=kube-controller-manager-key.pem \
  --embed-certs=true \
  --kubeconfig=kube-controller-manager.kubeconfig

kubectl config set-context default \
  --cluster=kubernetes \
  --user=system:kube-controller-manager \
  --kubeconfig=kube-controller-manager.kubeconfig

kubectl config use-context default --kubeconfig=kube-controller-manager.kubeconfig
  1. kube-scheduler生成kubeconfigs
kubectl config set-cluster kubernetes \
  --certificate-authority=ca.pem \
  --embed-certs=true \
  --server=https://127.0.0.1:6443 \
  --kubeconfig=kube-scheduler.kubeconfig

kubectl config set-credentials system:kube-scheduler \
  --client-certificate=kube-scheduler.pem \
  --client-key=kube-scheduler-key.pem \
  --embed-certs=true \
  --kubeconfig=kube-scheduler.kubeconfig

kubectl config set-context default \
  --cluster=kubernetes \
  --user=system:kube-scheduler \
  --kubeconfig=kube-scheduler.kubeconfig

kubectl config use-context default --kubeconfig=kube-scheduler.kubeconfig
  1. admin用户生成kubeconfigs
kubectl config set-cluster kubernetes \
  --certificate-authority=ca.pem \
  --embed-certs=true \
  --server=https://127.0.0.1:6443 \
  --kubeconfig=admin.kubeconfig

kubectl config set-credentials admin \
  --client-certificate=admin.pem \
  --client-key=admin-key.pem \
  --embed-certs=true \
  --kubeconfig=admin.kubeconfig

kubectl config set-context default \
  --cluster=kubernetes \
  --user=admin \
  --kubeconfig=admin.kubeconfig

kubectl config use-context default --kubeconfig=admin.kubeconfig
  1. 分发kubeconfigs配置文件
  • kubeletkube-proxykubeconfigs分发到Worker节点
WORKERS=("cluster2" "cluster3")
for instance in ${WORKERS[@]}; do
  scp ${instance}.kubeconfig kube-proxy.kubeconfig ${instance}:~/
done
  • kube-controller-managerkube-schedulerkubeconfigs分发到Master节点
MASTERS=("cluster1" "cluster2")
for instance in ${MASTERS[@]}; do
  scp admin.kubeconfig kube-controller-manager.kubeconfig kube-scheduler.kubeconfig ${instance}:~/
done

部署ETCD集群

  1. 配置etcd证书文件
mkdir -p /etc/etcd /var/lib/etcd
chmod 700 /var/lib/etcd
cp ca.pem kubernetes-key.pem kubernetes.pem /etc/etcd/
  1. 配置etcd.service文件
  • ECCD_IP: 为当前ectd存储服务器的IP
ETCD_NAME=$(hostname -s)
ETCD_IP=192.168.200.11
ETCD_NAMES=(cluster1 cluster2 cluster3)
ETCD_IPS=(192.168.200.11 192.168.200.22 192.168.200.33)
cat <<EOF > /etc/systemd/system/etcd.service
[Unit]
Description=etcd
Documentation=https://github.com/coreos

[Service]
Type=notify
ExecStart=/usr/local/bin/etcd \\
  --name ${ETCD_NAME} \\
  --cert-file=/etc/etcd/kubernetes.pem \\
  --key-file=/etc/etcd/kubernetes-key.pem \\
  --peer-cert-file=/etc/etcd/kubernetes.pem \\
  --peer-key-file=/etc/etcd/kubernetes-key.pem \\
  --trusted-ca-file=/etc/etcd/ca.pem \\
  --peer-trusted-ca-file=/etc/etcd/ca.pem \\
  --peer-client-cert-auth \\
  --client-cert-auth \\
  --initial-advertise-peer-urls https://${ETCD_IP}:2380 \\
  --listen-peer-urls https://${ETCD_IP}:2380 \\
  --listen-client-urls https://${ETCD_IP}:2379,https://127.0.0.1:2379 \\
  --advertise-client-urls https://${ETCD_IP}:2379 \\
  --initial-cluster-token etcd-cluster-0 \\
  --initial-cluster ${ETCD_NAMES[0]}=https://${ETCD_IPS[0]}:2380,${ETCD_NAMES[1]}=https://${ETCD_IPS[1]}:2380,${ETCD_NAMES[2]}=https://${ETCD_IPS[2]}:2380 \\
  --initial-cluster-state new \\
  --data-dir=/var/lib/etcd
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF
  1. 启动etcd集群
systemctl daemon-reload && systemctl enable etcd && systemctl start etcd
  1. 验证etcd集群
ETCDCTL_API=3 etcdctl member list \
--endpoints=https://127.0.0.1:2379 \
--cacert=/etc/etcd/ca.pem \
--cert=/etc/etcd/kubernetes.pem \
--key=/etc/etcd/kubernetes-key.pem

成功输出结果如下(不同机器不同):

87db4208f2c1d75, started, cluster2, https://192.168.200.22:2380, https://192.168.200.22:2379, false
95c5677668e390bf, started, cluster1, https://192.168.200.11:2380, https://192.168.200.11:2379, false
d728cb204dcd87a3, started, cluster3, https://192.168.200.33:2380, https://192.168.200.33:2379, false

部署kubernetes控制面板

每个组件有多个点保证高可用。 我们在cluster1cluster2上部署kube-apiserver,kube-contronller-manager,kube-scheduler

  1. 配置API Server(每个master节点都需要配置)
mkdir -p /etc/kubernetes/ssl

mv ca.pem ca-key.pem kubernetes-key.pem kubernetes.pem \
  service-account-key.pem service-account.pem \
  proxy-client.pem proxy-client-key.pem \
  /etc/kubernetes/ssl

IP=192.168.200.11
APISERVER_COUNT=2
ETCD_ENDPOINTS=(192.168.200.11 192.168.200.22 192.168.200.33)

cat <<EOF > /etc/systemd/system/kube-apiserver.service
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes

[Service]
ExecStart=/usr/local/bin/kube-apiserver \\
  --advertise-address=${IP} \\
  --allow-privileged=true \\
  --apiserver-count=${APISERVER_COUNT} \\
  --audit-log-maxage=30 \\
  --audit-log-maxbackup=3 \\
  --audit-log-maxsize=100 \\
  --audit-log-path=/var/log/audit.log \\
  --authorization-mode=Node,RBAC \\
  --bind-address=0.0.0.0 \\
  --client-ca-file=/etc/kubernetes/ssl/ca.pem \\
  --enable-admission-plugins=NamespaceLifecycle,NodeRestriction,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota \\
  --etcd-cafile=/etc/kubernetes/ssl/ca.pem \\
  --etcd-certfile=/etc/kubernetes/ssl/kubernetes.pem \\
  --etcd-keyfile=/etc/kubernetes/ssl/kubernetes-key.pem \\
  --etcd-servers=https://${ETCD_ENDPOINTS[0]}:2379,https://${ETCD_ENDPOINTS[1]}:2379,https://${ETCD_ENDPOINTS[2]}:2379 \\
  --event-ttl=1h \\
  --kubelet-certificate-authority=/etc/kubernetes/ssl/ca.pem \\
  --kubelet-client-certificate=/etc/kubernetes/ssl/kubernetes.pem \\
  --kubelet-client-key=/etc/kubernetes/ssl/kubernetes-key.pem \\
  --service-account-issuer=api \\
  --service-account-key-file=/etc/kubernetes/ssl/service-account.pem \\
  --service-account-signing-key-file=/etc/kubernetes/ssl/service-account-key.pem \\
  --api-audiences=api,vault,factors \\
  --service-cluster-ip-range=10.233.0.0/16 \\
  --service-node-port-range=30000-32767 \\
  --proxy-client-cert-file=/etc/kubernetes/ssl/proxy-client.pem \\
  --proxy-client-key-file=/etc/kubernetes/ssl/proxy-client-key.pem \\
  --runtime-config=api/all=true \\
  --requestheader-client-ca-file=/etc/kubernetes/ssl/ca.pem \\
  --requestheader-allowed-names=aggregator \\
  --requestheader-extra-headers-prefix=X-Remote-Extra- \\
  --requestheader-group-headers=X-Remote-Group \\
  --requestheader-username-headers=X-Remote-User \\
  --tls-cert-file=/etc/kubernetes/ssl/kubernetes.pem \\
  --tls-private-key-file=/etc/kubernetes/ssl/kubernetes-key.pem \\
  --v=1
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF
  1. 配置kube-controller-manager
mv kube-controller-manager.kubeconfig /etc/kubernetes/

cat <<EOF > /etc/systemd/system/kube-controller-manager.service
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes

[Service]
ExecStart=/usr/local/bin/kube-controller-manager \\
  --bind-address=0.0.0.0 \\
  --cluster-cidr=10.200.0.0/16 \\
  --cluster-name=kubernetes \\
  --cluster-signing-cert-file=/etc/kubernetes/ssl/ca.pem \\
  --cluster-signing-key-file=/etc/kubernetes/ssl/ca-key.pem \\
  --cluster-signing-duration=876000h0m0s \\
  --kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \\
  --leader-elect=true \\
  --root-ca-file=/etc/kubernetes/ssl/ca.pem \\
  --service-account-private-key-file=/etc/kubernetes/ssl/service-account-key.pem \\
  --service-cluster-ip-range=10.233.0.0/16 \\
  --use-service-account-credentials=true \\
  --v=1
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF
  1. 配置kube-scheduler
mv kube-scheduler.kubeconfig /etc/kubernetes

cat <<EOF > /etc/systemd/system/kube-scheduler.service
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes

[Service]
ExecStart=/usr/local/bin/kube-scheduler \\
  --authentication-kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \\
  --authorization-kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \\
  --kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \\
  --leader-elect=true \\
  --bind-address=0.0.0.0 \\
  --port=0 \\
  --v=1
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF
  1. 启动服务
systemctl daemon-reload
systemctl enable kube-apiserver
systemctl enable kube-controller-manager
systemctl enable kube-scheduler
systemctl start kube-apiserver
systemctl start kube-controller-manager
systemctl start kube-scheduler
  1. 服务验证
netstat -ntlp

正常输出如下:

tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      18829/sshd
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      853/master
tcp        0      0 192.168.200.11:2379     0.0.0.0:*               LISTEN      30516/etcd
tcp        0      0 127.0.0.1:2379          0.0.0.0:*               LISTEN      30516/etcd
tcp        0      0 192.168.200.11:2380     0.0.0.0:*               LISTEN      30516/etcd
tcp6       0      0 ::1:25                  :::*                    LISTEN      853/master
tcp6       0      0 :::6443                 :::*                    LISTEN      30651/kube-apiserve
tcp6       0      0 :::10257                :::*                    LISTEN      30666/kube-controll
tcp6       0      0 :::10259                :::*                    LISTEN      30679/kube-schedule
  1. 配置kubectl kubectl用来管理kubernetes集群的客户端工具。
mkdir ~/.kube/
mv ~/admin.kubeconfig ~/.kube/config
kubectl get nodes

授权apiserver调用kubelet API,在执行kubectl exec/run/logsapiserver会转发到kubelet

kubectl create clusterrolebinding kube-apiserver:kubelet-apis --clusterrole=system:kubelet-api-admin --user kubernetes

Deploy kubernetes Worker Node

每个节点上都会部署:

  • kubelet
  • kube-proxy
  • container runtime
  • cni
  • nginx-proxy
  1. Container Runtine(containerd)
VERSION=1.4.3
wget https://github.com/containerd/containerd/releases/download/v${VERSION}/cri-containerd-cni-${VERSION}-linux-amd64.tar.gz
tar -xvf cri-containerd-cni-${VERSION}-linux-amd64.tar.gz
cp etc/crictl.yaml /etc/
cp etc/systemd/system/containerd.service /etc/systemd/system/
cp -r usr /
  1. containerd配置文件
mkdir -p /etc/containerd
containerd config default > /etc/containerd/config.toml
# Options
vi /etc/containerd/config.toml
  1. 启动containerd
systemctl enable containerd
systemctl start containerd
systemctl status containerd
  1. 配置kubelet
  • 准备配置文件
mkdir -p /etc/kubernetes/ssl/
mv ${HOSTNAME}-key.pem ${HOSTNAME}.pem ca.pem ca-key.pem /etc/kubernetes/ssl/
mv ${HOSTNAME}.kubeconfig /etc/kubernetes/kubeconfig
IP=192.168.200.22

cat <<EOF > /etc/kubernetes/kubelet-config.yaml
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
authentication:
  anonymous:
    enabled: false
  webhook:
    enabled: true
  x509:
    clientCAFile: "/etc/kubernetes/ssl/ca.pem"
authorization:
  mode: Webhook
clusterDomain: "cluster.local"
clusterDNS:
  - "169.254.25.10"
podCIDR: "10.200.0.0/16"
address: ${IP}
readOnlyPort: 0
staticPodPath: /etc/kubernetes/manifests
healthzPort: 10248
healthzBindAddress: 127.0.0.1
kubeletCgroups: /systemd/system.slice
resolvConf: "/etc/resolv.conf"
runtimeRequestTimeout: "15m"
kubeReserved:
  cpu: 200m
  memory: 512M
tlsCertFile: "/etc/kubernetes/ssl/${HOSTNAME}.pem"
tlsPrivateKeyFile: "/etc/kubernetes/ssl/${HOSTNAME}-key.pem"
EOF
  • 配置服务
cat <<EOF > /etc/systemd/system/kubelet.service
[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/kubernetes/kubernetes
After=containerd.service
Requires=containerd.service

[Service]
ExecStart=/usr/local/bin/kubelet \\
  --config=/etc/kubernetes/kubelet-config.yaml \\
  --container-runtime=remote \\
  --container-runtime-endpoint=unix:///var/run/containerd/containerd.sock \\
  --image-pull-progress-deadline=2m \\
  --kubeconfig=/etc/kubernetes/kubeconfig \\
  --network-plugin=cni \\
  --node-ip=${IP} \\
  --register-node=true \\
  --v=2
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF
  1. 配置nginx-proxy nginx-proxy是有一个用于Worker节点访问apiserver的一个代理, 是apiserver一个优雅的高可用方案。 它使用kubeletstaticpod方式启动,让每个节点都可以均衡的访问每个apiserver服务 优雅的替代了通过虚拟ip访问apiserver的方式。

只需要在没有``apiserver的节点部署

注意stream中有几个节点写几个

mkdir -p /etc/nginx
MASTER_IPS=(10.155.19.223 10.155.19.64)

cat <<EOF > /etc/nginx/nginx.conf
error_log stderr notice;

worker_processes 2;
worker_rlimit_nofile 130048;
worker_shutdown_timeout 10s;

events {
  multi_accept on;
  use epoll;
  worker_connections 16384;
}

stream {
  upstream kube_apiserver {
    least_conn;
    server ${MASTER_IPS[0]}:6443;
    server ${MASTER_IPS[1]}:6443;
    ...
    server ${MASTER_IPS[N]}:6443;
  }

  server {
    listen        127.0.0.1:6443;
    proxy_pass    kube_apiserver;
    proxy_timeout 10m;
    proxy_connect_timeout 1s;
  }
}

http {
  aio threads;
  aio_write on;
  tcp_nopush on;
  tcp_nodelay on;

  keepalive_timeout 5m;
  keepalive_requests 100;
  reset_timedout_connection on;
  server_tokens off;
  autoindex off;

  server {
    listen 8081;
    location /healthz {
      access_log off;
      return 200;
    }
    location /stub_status {
      stub_status on;
      access_log off;
    }
  }
}
EOF
  • Nginx manifest
cat <<EOF > /etc/kubernetes/manifests/nginx-proxy.yaml
apiVersion: v1
kind: Pod
metadata:
  name: nginx-proxy
  namespace: kube-system
  labels:
    addonmanager.kubernetes.io/mode: Reconcile
    k8s-app: kube-nginx
spec:
  hostNetwork: true
  dnsPolicy: ClusterFirstWithHostNet
  nodeSelector:
    kubernetes.io/os: linux
  priorityClassName: system-node-critical
  containers:
  - name: nginx-proxy
    image: docker.io/library/nginx:1.19
    imagePullPolicy: IfNotPresent
    resources:
      requests:
        cpu: 25m
        memory: 32M
    securityContext:
      privileged: true
    livenessProbe:
      httpGet:
        path: /healthz
        port: 8081
    readinessProbe:
      httpGet:
        path: /healthz
        port: 8081
    volumeMounts:
    - mountPath: /etc/nginx
      name: etc-nginx
      readOnly: true
  volumes:
  - name: etc-nginx
    hostPath:
      path: /etc/nginx
EOF
  1. 配置kube-proxy
  • 配置文件
mv kube-proxy.kubeconfig /etc/kubernetes/
cat <<EOF > /etc/kubernetes/kube-proxy-config.yaml
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
bindAddress: 0.0.0.0
clientConnection:
  kubeconfig: "/etc/kubernetes/kube-proxy.kubeconfig"
clusterCIDR: "10.200.0.0/16"
mode: ipvs
EOF
  • kube-proxy服务文件
cat <<EOF > /etc/systemd/system/kube-proxy.service
[Unit]
Description=Kubernetes Kube Proxy
Documentation=https://github.com/kubernetes/kubernetes

[Service]
ExecStart=/usr/local/bin/kube-proxy \\
  --config=/etc/kubernetes/kube-proxy-config.yaml
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF
  1. 服务启动
systemctl daemon-reload
systemctl enable kubelet kube-proxy
systemctl start kubelet kube-proxy
journalctl -f -u kubelet
journalctl -f -u kube-proxy
  1. 手动下载镜像pause(服务器无法访问外网) 在每个节点下载(master节点不下载可能不能成功)
crictl pull registry.cn-hangzhou.aliyuncs.com/kubernetes-kubespray/pause:3.2
ctr -n k8s.io i tag  registry.cn-hangzhou.aliyuncs.com/kubernetes-kubespray/pause:3.2 k8s.gcr.io/pause:3.2
  1. 主动拉取/etc/kubernetes/manifests/nginx-proxy.yaml文件中的nginx镜像 具体版本,查看文件中的版本信息
crictl pull docker.io/library/nginx:1.19

网络插件Calico

  1. YAML文件需要从官网下载
  • 链接: https://docs.projectcalico.org/getting-started/kubernetes/self-managed-onprem/onpremises
  • 有两种配置,50节点以内或者以上
  • 具体版本看官网信息,一下链接可能版本会不同
curl https://raw.githubusercontent.com/projectcalico/calico/v3.24.5/manifests/calico.yaml -O
  1. 修改IP自动发现方式
  • autodetect 可能会有问题
  • 当kubelet的启动参数中存在–node-ip的时候,以host-network模式启动的pod的status.hostIP字段就会自动填入kubelet中指定的ip地址

修改前:

- name: IP
  value: "autodetect"

修改后:

- name: IP
  valueFrom:
    fieldRef:
      fieldPath: status.hostIP
  1. 修改CIDR

修改前:

# - name: CALICO_IPV4POOL_CIDR
#   value: "192.168.0.0/16"

修改后:

- name: CALICO_IPV4POOL_CIDR
  value: "10.200.0.0/16"
  1. 启动calico
kubectl apply -f calico.yaml

DNS插件CoreDNS

  1. Deploy CoreDNS
  • 设置corednscluster-ip
  • 下载coredns.yaml
  • 替换cluster-ip
  • 创建coredns
COREDNS_CLUSTER_IP=10.233.0.10
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
  labels:
      addonmanager.kubernetes.io/mode: EnsureExists
data:
  Corefile: |
    .:53 {
        errors
        health {
            lameduck 5s
        }
        ready
        kubernetes cluster.local in-addr.arpa ip6.arpa {
          pods insecure
          fallthrough in-addr.arpa ip6.arpa
        }
        prometheus :9153
        forward . /etc/resolv.conf {
          prefer_udp
        }
        cache 30
        loop
        reload
        loadbalance
    }
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: coredns
  namespace: kube-system
  labels:
    addonmanager.kubernetes.io/mode: Reconcile
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
    addonmanager.kubernetes.io/mode: Reconcile
  name: system:coredns
rules:
  - apiGroups:
      - ""
    resources:
      - endpoints
      - services
      - pods
      - namespaces
    verbs:
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - nodes
    verbs:
      - get
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
    addonmanager.kubernetes.io/mode: EnsureExists
  name: system:coredns
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:coredns
subjects:
  - kind: ServiceAccount
    name: coredns
    namespace: kube-system
---
apiVersion: v1
kind: Service
metadata:
  name: coredns
  namespace: kube-system
  labels:
    k8s-app: kube-dns
    kubernetes.io/name: "coredns"
    addonmanager.kubernetes.io/mode: Reconcile
  annotations:
    prometheus.io/port: "9153"
    prometheus.io/scrape: "true"
spec:
  selector:
    k8s-app: kube-dns
  clusterIP: ${COREDNS_CLUSTER_IP}
  ports:
    - name: dns
      port: 53
      protocol: UDP
    - name: dns-tcp
      port: 53
      protocol: TCP
    - name: metrics
      port: 9153
      protocol: TCP
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: "coredns"
  namespace: kube-system
  labels:
    k8s-app: "kube-dns"
    addonmanager.kubernetes.io/mode: Reconcile
    kubernetes.io/name: "coredns"
spec:
  replicas: 2
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 0
      maxSurge: 10%
  selector:
    matchLabels:
      k8s-app: kube-dns
  template:
    metadata:
      labels:
        k8s-app: kube-dns
      annotations:
        seccomp.security.alpha.kubernetes.io/pod: 'runtime/default'
    spec:
      priorityClassName: system-cluster-critical
      nodeSelector:
        kubernetes.io/os: linux
      serviceAccountName: coredns
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
          - topologyKey: "kubernetes.io/hostname"
            labelSelector:
              matchLabels:
                k8s-app: kube-dns
        nodeAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
          - weight: 100
            preference:
              matchExpressions:
              - key: node-role.kubernetes.io/master
                operator: In
                values:
                - ""
      containers:
      - name: coredns
        image: "docker.io/coredns/coredns:1.6.7"
        imagePullPolicy: IfNotPresent
        resources:
          # TODO: Set memory limits when we've profiled the container for large
          # clusters, then set request = limit to keep this container in
          # guaranteed class. Currently, this container falls into the
          # "burstable" category so the kubelet doesn't backoff from restarting it.
          limits:
            memory: 170Mi
          requests:
            cpu: 100m
            memory: 70Mi
        args: [ "-conf", "/etc/coredns/Corefile" ]
        volumeMounts:
        - name: config-volume
          mountPath: /etc/coredns
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        - containerPort: 9153
          name: metrics
          protocol: TCP
        securityContext:
          allowPrivilegeEscalation: false
          capabilities:
            add:
            - NET_BIND_SERVICE
            drop:
            - all
          readOnlyRootFilesystem: true
        livenessProbe:
          httpGet:
            path: /health
            port: 8080
            scheme: HTTP
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 10
        readinessProbe:
          httpGet:
            path: /ready
            port: 8181
            scheme: HTTP
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 10
      dnsPolicy: Default
      volumes:
        - name: config-volume
          configMap:
            name: coredns
            items:
            - key: Corefile
              path: Corefile
  ```

```bash
sed -i "s/\${COREDNS_CLUSTER_IP}/${COREDNS_CLUSTER_IP}/g" coredns.yaml
kubectl apply -f coredns.yaml
  1. Deploy NodeLocal DNSCache
  • 设置corednscluster-ip
  • 下载nodelocaldns.yaml
  • 替换`cluster-ip
  • 创建nodelocaldns
COREDNS_CLUSTER_IP=10.233.0.10
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: nodelocaldns
  namespace: kube-system
  labels:
    addonmanager.kubernetes.io/mode: EnsureExists

data:
  Corefile: |
    cluster.local:53 {
        errors
        cache {
            success 9984 30
            denial 9984 5
        }
        reload
        loop
        bind 169.254.25.10
        forward . ${COREDNS_CLUSTER_IP} {
            force_tcp
        }
        prometheus :9253
        health 169.254.25.10:9254
    }
    in-addr.arpa:53 {
        errors
        cache 30
        reload
        loop
        bind 169.254.25.10
        forward . ${COREDNS_CLUSTER_IP} {
            force_tcp
        }
        prometheus :9253
    }
    ip6.arpa:53 {
        errors
        cache 30
        reload
        loop
        bind 169.254.25.10
        forward . ${COREDNS_CLUSTER_IP} {
            force_tcp
        }
        prometheus :9253
    }
    .:53 {
        errors
        cache 30
        reload
        loop
        bind 169.254.25.10
        forward . /etc/resolv.conf
        prometheus :9253
    }
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: nodelocaldns
  namespace: kube-system
  labels:
    k8s-app: kube-dns
    addonmanager.kubernetes.io/mode: Reconcile
spec:
  selector:
    matchLabels:
      k8s-app: nodelocaldns
  template:
    metadata:
      labels:
        k8s-app: nodelocaldns
      annotations:
        prometheus.io/scrape: 'true'
        prometheus.io/port: '9253'
    spec:
      priorityClassName: system-cluster-critical
      serviceAccountName: nodelocaldns
      hostNetwork: true
      dnsPolicy: Default  # Don't use cluster DNS.
      tolerations:
      - effect: NoSchedule
        operator: "Exists"
      - effect: NoExecute
        operator: "Exists"
      containers:
      - name: node-cache
        image: "registry.cn-hangzhou.aliyuncs.com/kubernetes-kubespray/dns_k8s-dns-node-cache:1.16.0"
        resources:
          limits:
            memory: 170Mi
          requests:
            cpu: 100m
            memory: 70Mi
        args: [ "-localip", "169.254.25.10", "-conf", "/etc/coredns/Corefile", "-upstreamsvc", "coredns" ]
        securityContext:
          privileged: true
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        - containerPort: 9253
          name: metrics
          protocol: TCP
        livenessProbe:
          httpGet:
            host: 169.254.25.10
            path: /health
            port: 9254
            scheme: HTTP
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 10
        readinessProbe:
          httpGet:
            host: 169.254.25.10
            path: /health
            port: 9254
            scheme: HTTP
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 10
        volumeMounts:
        - name: config-volume
          mountPath: /etc/coredns
        - name: xtables-lock
          mountPath: /run/xtables.lock
      volumes:
        - name: config-volume
          configMap:
            name: nodelocaldns
            items:
            - key: Corefile
              path: Corefile
        - name: xtables-lock
          hostPath:
            path: /run/xtables.lock
            type: FileOrCreate
      # Minimize downtime during a rolling upgrade or deletion; tell Kubernetes to do a "force
      # deletion": https://kubernetes.io/docs/concepts/workloads/pods/pod/#termination-of-pods.
      terminationGracePeriodSeconds: 0
  updateStrategy:
    rollingUpdate:
      maxUnavailable: 20%
    type: RollingUpdate
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nodelocaldns
  namespace: kube-system
  labels:
    addonmanager.kubernetes.io/mode: Reconcile
sed -i "s/\${COREDNS_CLUSTER_IP}/${COREDNS_CLUSTER_IP}/g" nodelocaldns.yaml
kubectl apply -f nodelocaldns.yaml

集群冒烟测试

  1. 创建nginx ds
cat > nginx-ds.yml <<EOF
apiVersion: v1
kind: Service
metadata:
  name: nginx-ds
  labels:
    app: nginx-ds
spec:
  type: NodePort
  selector:
    app: nginx-ds
  ports:
  - name: http
    port: 80
    targetPort: 80
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: nginx-ds
spec:
  selector:
    matchLabels:
      app: nginx-ds
  template:
    metadata:
      labels:
        app: nginx-ds
    spec:
      containers:
      - name: my-nginx
        image: nginx:1.19
        ports:
        - containerPort: 80
EOF

kubectl apply -f nginx-ds.yml
  1. 检查各种IP连通性
  • 查看各Node上的Pod IP连通性
kubectl get pods -o wide

如下图 Pod IP

  • 在每个Worker节点上ping pod ip
ping <pod-ip> #上图中查出来的
  • 查看service可达性
kubectl get svc

# 在每个`Worker`节点上访问服务
curl <service-ip>:<port> # 80

在每个节点上检查`node-port`可用性
curl <node-ip>:<port> # node-ip: 192.168.200.22, port: 上图中80后面的端口号

如下图: Server IP

  1. 检查dns可用性
cat > pod-nginx.yaml <<EOF
apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  containers:
  - name: nginx
    image: docker.io/library/nginx:1.19
    ports:
    - containerPort: 80
EOF

# 创建pod
$ kubectl apply -f pod-nginx.yaml

# 进入pod,查看dns(根据pod名)
$ kubectl exec nginx -it -- /bin/bash

# 查看dns配置(IP)
root@nginx:/# cat /etc/resolv.conf

# 查看名字是否可以正确解析
root@nginx:/# curl nginx-ds