• 011.Kubernetes二进制master节点部署kube-controller-manager


    一 部署kube-controller-manager

    1.1 高可用kube-controller-manager介绍

    本实验部署一个三实例 kube-controller-manager 的集群,启动后将通过竞争选举机制产生一个 leader 节点,其它节点为阻塞状态。当 leader 节点不可用时,阻塞的节点将再次进行选举产生新的 leader 节点,从而保证服务的可用性。

    为保证通信安全,本文档先生成 x509 证书和私钥,kube-controller-manager 在如下两种情况下使用该证书:

    • 与 kube-apiserver 的安全端口通信;
    • 在安全端口(https,10252) 输出 prometheus 格式的 metrics。

    1.2 创建kube-controller-manager证书和私钥

      1 [root@master01 ~]# cd /opt/k8s/work
      2 [root@master01 work]# source /root/environment.sh
      3 [root@master01 work]# cat > kube-controller-manager-csr.json <<EOF
      4 {
      5   "CN": "system:kube-controller-manager",
      6   "hosts": [
      7     "127.0.0.1",
      8     "172.24.8.71",
      9     "172.24.8.72",
     10     "172.24.8.73",
     11     "172.24.8.100"
     12   ],
     13   "key": {
     14     "algo": "rsa",
     15     "size": 2048
     16   },
     17   "names": [
     18     {
     19       "C": "CN",
     20       "ST": "Shanghai",
     21       "L": "Shanghai",
     22       "O": "system:kube-controller-manager",
     23       "OU": "System"
     24     }
     25   ]
     26 }
     27 EOF		#创建kube-controller-manager的CA证书请求文件

    解释:

    hosts 列表包含所有 kube-controller-manager 节点 IP;

    CN 和 O 均为 system:kube-controller-manager,kubernetes 内置的 ClusterRoleBindings system:kube-controller-manager 赋予 kube-controller-manager 工作所需的权限。

      1 [root@master01 ~]# cd /opt/k8s/work
      2 [root@master01 work]# cfssl gencert -ca=/opt/k8s/work/ca.pem 
      3 -ca-key=/opt/k8s/work/ca-key.pem -config=/opt/k8s/work/ca-config.json 
      4 -profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager	#生成密钥和证书

    提示:本步骤操作仅需要在master01节点操作。

    1.3 分发证书和私钥

      1 [root@master01 ~]# cd /opt/k8s/work
      2 [root@master01 work]# source /root/environment.sh
      3 [root@master01 work]# for master_ip in ${MASTER_IPS[@]}
      4   do
      5     echo ">>> ${master_ip}"
      6     scp kube-controller-manager*.pem root@${master_ip}:/etc/kubernetes/cert/
      7   done

    提示:本步骤操作仅需要在master01节点操作。

    1.4 创建和分发kubeconfig

    kube-controller-manager 使用 kubeconfig 文件访问 apiserver,该文件提供了 apiserver 地址、嵌入的 CA 证书和 kube-controller-manager 证书:

      1 [root@master01 ~]# cd /opt/k8s/work
      2 [root@master01 work]# source /root/environment.sh
      3 [root@master01 work]# kubectl config set-cluster kubernetes 
      4   --certificate-authority=/opt/k8s/work/ca.pem 
      5   --embed-certs=true 
      6   --server=${KUBE_APISERVER} 
      7   --kubeconfig=kube-controller-manager.kubeconfig
      8 
      9 [root@master01 work]# kubectl config set-credentials system:kube-controller-manager 
     10   --client-certificate=kube-controller-manager.pem 
     11   --client-key=kube-controller-manager-key.pem 
     12   --embed-certs=true 
     13   --kubeconfig=kube-controller-manager.kubeconfig
     14 
     15 [root@master01 work]# kubectl config set-context system:kube-controller-manager 
     16   --cluster=kubernetes 
     17   --user=system:kube-controller-manager 
     18   --kubeconfig=kube-controller-manager.kubeconfig
     19 
     20 [root@master01 work]# kubectl config use-context system:kube-controller-manager --kubeconfig=kube-controller-manager.kubeconfig
     21 
     22 [root@master01 ~]# cd /opt/k8s/work
     23 [root@master01 work]# source /root/environment.sh
     24 [root@master01 work]# for master_ip in ${MASTER_IPS[@]}
     25   do
     26     echo ">>> ${master_ip}"
     27     scp kube-controller-manager.kubeconfig root@${master_ip}:/etc/kubernetes/
     28   done

    提示:本步骤操作仅需要在master01节点操作。

    1.5 创建kube-controller-manager的systemd

      1 [root@master01 ~]# cd /opt/k8s/work
      2 [root@master01 work]# source /root/environment.sh
      3 [root@master01 work]# cat > kube-controller-manager.service.template <<EOF
      4 [Unit]
      5 Description=Kubernetes Controller Manager
      6 Documentation=https://github.com/GoogleCloudPlatform/kubernetes
      7 
      8 [Service]
      9 WorkingDirectory=${K8S_DIR}/kube-controller-manager
     10 ExecStart=/opt/k8s/bin/kube-controller-manager \
     11   --secure-port=10257 \
     12   --bind-address=127.0.0.1 \
     13   --profiling \
     14   --cluster-name=kubernetes \
     15   --controllers=*,bootstrapsigner,tokencleaner \
     16   --kube-api-qps=1000 \
     17   --kube-api-burst=2000 \
     18   --leader-elect \
     19   --use-service-account-credentials\
     20   --concurrent-service-syncs=2 \
     21   --tls-cert-file=/etc/kubernetes/cert/kube-controller-manager.pem \
     22   --tls-private-key-file=/etc/kubernetes/cert/kube-controller-manager-key.pem \
     23   --authentication-kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \
     24   --client-ca-file=/etc/kubernetes/cert/ca.pem \
     25   --requestheader-allowed-names="system:metrics-server" \
     26   --requestheader-client-ca-file=/etc/kubernetes/cert/ca.pem \
     27   --requestheader-extra-headers-prefix="X-Remote-Extra-" \
     28   --requestheader-group-headers=X-Remote-Group \
     29   --requestheader-username-headers=X-Remote-User \
     30   --cluster-signing-cert-file=/etc/kubernetes/cert/ca.pem \
     31   --cluster-signing-key-file=/etc/kubernetes/cert/ca-key.pem \
     32   --experimental-cluster-signing-duration=87600h \
     33   --horizontal-pod-autoscaler-sync-period=10s \
     34   --concurrent-deployment-syncs=10 \
     35   --concurrent-gc-syncs=30 \
     36   --node-cidr-mask-size=24 \
     37   --service-cluster-ip-range=${SERVICE_CIDR} \
     38   --cluster-cidr=${CLUSTER_CIDR} \
     39   --pod-eviction-timeout=6m \
     40   --terminated-pod-gc-threshold=10000 \
     41   --root-ca-file=/etc/kubernetes/cert/ca.pem \
     42   --service-account-private-key-file=/etc/kubernetes/cert/ca-key.pem \
     43   --kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \
     44   --logtostderr=true \
     45   --v=2
     46 Restart=on-failure
     47 RestartSec=5
     48 
     49 [Install]
     50 WantedBy=multi-user.target
     51 EOF

    提示:本步骤操作仅需要在master01节点操作。

    1.6 分发systemd

      1 [root@master01 ~]# cd /opt/k8s/work
      2 [root@master01 work]# source /root/environment.sh
      3 [root@master01 work]# for master_ip in ${MASTER_IPS[@]}
      4   do
      5     echo ">>> ${master_ip}"
      6     scp kube-controller-manager.service.template root@${master_ip}:/etc/systemd/system/kube-controller-manager.service
      7   done						#分发system

    提示:本步骤操作仅需要在master01节点操作。

    二 启动并验证

    2.1 启动kube-controller-manager 服务

      1 [root@master01 ~]# cd /opt/k8s/work
      2 [root@master01 work]# source /root/environment.sh
      3 [root@master01 work]# for master_ip in ${MASTER_IPS[@]}
      4   do
      5     echo ">>> ${master_ip}"
      6     ssh root@${master_ip} "mkdir -p ${K8S_DIR}/kube-controller-manager"
      7     ssh root@${master_ip} "systemctl daemon-reload && systemctl enable kube-controller-manager && systemctl restart kube-controller-manager"
      8   done

    提示:本步骤操作仅需要在master01节点操作。

    2.2 检查kube-controller-manager 服务

      1 [root@master01 ~]# cd /opt/k8s/work
      2 [root@master01 work]# source /root/environment.sh
      3 [root@master01 work]# for master_ip in ${MASTER_IPS[@]}
      4   do
      5     echo ">>> ${master_ip}"
      6     ssh root@${master_ip} "systemctl status kube-controller-manager|grep Active"
      7   done

    提示:本步骤操作仅需要在master01节点操作。

    clipboard

    2.3 查看输出的 metrics

      1 [root@master01 work]# curl -s --cacert /opt/k8s/work/ca.pem --cert /opt/k8s/work/admin.pem --key /opt/k8s/work/admin-key.pem https://127.0.0.1:10257/metrics | head

    提示:本步骤操作仅需要在master01节点操作。

    2.4 查看权限

      1 [root@master01 ~]# kubectl describe clusterrole system:kube-controller-manager

    clipboard

    ClusteRole system:kube-controller-manager 的权限很小,只能创建 secret、serviceaccount 等资源对象,各 controller 的权限分散到 ClusterRole system:controller:XXX 中。

    当在 kube-controller-manager 的启动参数中添加 --use-service-account-credentials=true 参数,这样 main controller 会为各 controller 创建对应的 ServiceAccount XXX-controller。内置的 ClusterRoleBinding system:controller:XXX 将赋予各 XXX-controller ServiceAccount 对应的 ClusterRole system:controller:XXX 权限。

      1 [root@master01 ~]# kubectl get clusterrole | grep controller

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    如deployment controller:

      1 [root@master01 ~]# kubectl describe clusterrole system:controller:deployment-controller

    提示:本步骤操作仅需要在master01节点操作。

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    2.5 查看当前leader

      1 [root@master01 ~]# kubectl get endpoints kube-controller-manager --namespace=kube-system  -o yaml

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    kubelet 认证和授权:https://kubernetes.io/docs/admin/kubelet-authentication-authorization/#kubelet-authorization

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  • 原文地址:https://www.cnblogs.com/itzgr/p/11876066.html
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