K8S-Demo集群实践11：部署ipvs模式的kube-kubelet组件

• kubelet运行在每个worker节点上，接收kube-apiserver发送的请求，管理Pod容器，执行交互式命令，如exec、run、logs等
• kubelet启动时自动向kube-apiserver注册节点信息，内置的cadvisor统计和监控节点的资源使用情况

一、创建和分发kubelet bootstrap kubeconfig文件

[root@master1 ~]# cd /opt/install/kubeconfig
[root@master1 kubeconfig]# for node_name in ${ALL_NAMES[@]}
  do
    echo ">>> ${node_name}"

    # 创建 token
    export BOOTSTRAP_TOKEN=$(kubeadm token create \
      --description kubelet-bootstrap-token \
      --groups system:bootstrappers:${node_name} \
      --kubeconfig ~/.kube/config)

    # 设置集群参数
    kubectl config set-cluster k8s-demo \
      --certificate-authority=/opt/install/cert/ca.pem \
      --embed-certs=true \
      --server=${KUBE_APISERVER} \
      --kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig

    # 设置客户端认证参数
    kubectl config set-credentials kubelet-bootstrap \
      --token=${BOOTSTRAP_TOKEN} \
      --kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig

    # 设置上下文参数
    kubectl config set-context default \
      --cluster=k8s-demo \
      --user=kubelet-bootstrap \
      --kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig

    # 设置默认上下文
    kubectl config use-context default --kubeconfig=kubelet-bootstrap-${node_name}.kubeconfig
  done

• 分发到所有节点 3Master+3Node，方便监控每个节点的资源利用率

[root@master1 ~]# cd /opt/install/kubeconfig
[root@master1 kubeconfig]# for node_name in ${ALL_NAMES[@]}
  do
    echo ">>> ${node_name}"
    scp kubelet-bootstrap-${node_name}.kubeconfig root@${node_name}:/opt/k8s/etc//kubelet-bootstrap.kubeconfig
  done

二、创建和分发kubelet的参数配置文件

• 准备模板 kubelet-config.yaml.template

[root@master1 ~]# cd /opt/install/kubeconfig
[root@master1 kubeconfig]# cat > kubelet-config.yaml.template <<EOF
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: "##NODE_IP##"
staticPodPath: ""
syncFrequency: 1m
fileCheckFrequency: 20s
httpCheckFrequency: 20s
staticPodURL: ""
port: 10250
readOnlyPort: 0
rotateCertificates: true
serverTLSBootstrap: true
authentication:
  anonymous:
    enabled: false
  webhook:
    enabled: true
  x509:
    clientCAFile: "/opt/k8s/etc/cert/ca.pem"
authorization:
  mode: Webhook
registryPullQPS: 0
registryBurst: 20
eventRecordQPS: 0
eventBurst: 20
enableDebuggingHandlers: true
enableContentionProfiling: true
healthzPort: 10248
healthzBindAddress: "##NODE_IP##"
clusterDomain: "${CLUSTER_DNS_DOMAIN}"
clusterDNS:
  - "${CLUSTER_DNS_SVC_IP}"
nodeStatusUpdateFrequency: 10s
nodeStatusReportFrequency: 1m
imageMinimumGCAge: 2m
imageGCHighThresholdPercent: 85
imageGCLowThresholdPercent: 80
volumeStatsAggPeriod: 1m
kubeletCgroups: ""
systemCgroups: ""
cgroupRoot: ""
cgroupsPerQOS: true
cgroupDriver: cgroupfs
runtimeRequestTimeout: 10m
hairpinMode: promiscuous-bridge
maxPods: 220
podCIDR: "${CLUSTER_CIDR}"
podPidsLimit: -1
resolvConf: /etc/resolv.conf
maxOpenFiles: 1000000
kubeAPIQPS: 1000
kubeAPIBurst: 2000
serializeImagePulls: false
evictionHard:
  memory.available:  "100Mi"
  nodefs.available:  "10%"
  nodefs.inodesFree: "5%"
  imagefs.available: "15%"
evictionSoft: {}
enableControllerAttachDetach: true
failSwapOn: true
containerLogMaxSize: 20Mi
containerLogMaxFiles: 10
systemReserved: {}
kubeReserved: {}
systemReservedCgroup: ""
kubeReservedCgroup: ""
enforceNodeAllocatable: ["pods"]
EOF

• ddress：kubelet安全端口（https，10250）监听的地址，不能为127.0.0.1，否则kube-apiserver、heapster等不能调用kubelet的API
• readOnlyPort=0：关闭只读端口(默认 10255)，等效为未指定
• authentication.anonymous.enabled：设置为false，不允许匿名访问10250端口
• authentication.x509.clientCAFile：指定签名客户端证书的CA证书，开启HTTP证书认证
• authentication.webhook.enabled=true：开启HTTPS bearer token认证
• 分发到所有节点

[root@master1 ~]# cd /opt/install/kubeconfig
[root@master1 kubeconfig]# for nod