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。

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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

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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

posted @ 2019-11-17 13:17  木二  阅读(779)  评论(0)  编辑  收藏  举报