Kubernetes

二进制部署 Kubernetes （Ubuntu 18.04 Server）

第五节：部署 master 节点

Posted by ZYT on July 31, 2020

kubernetes master 节点运行如下组件：

  • kube-apiserver
  • kube-scheduler
  • kube-controller-manager

kube-apiserver、kube-scheduler 和 kube-controller-manager 均以多实例模式运行：

  • kube-scheduler 和 kube-controller-manager 会自动选举产生一个 leader 实例，其它实例处于阻塞模式，当 leader 挂了后，重新选举产生新的 leader，从而保证服务可用性；
  • kube-apiserver 是无状态的，可以通过 kube-nginx 进行代理访问，从而保证服务可用性；

1. 构建分发

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
    do
        echo ">>> ${node_ip}"
        scp {apiextensions-apiserver,kube-apiserver,kube-controller-manager,kube-proxy,kube-scheduler,kubeadm,kubectl,kubelet,mounter} root@${node_ip}:/opt/k8s/bin/
        ssh root@${node_ip} "chmod +x /opt/k8s/bin/*"
    done

2. 部署 kube-apiserver 集群

(1) 创建 kubernetes-master 证书和私钥

cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > kubernetes-csr.json <<EOF
{
  "CN": "kubernetes-master",
  "hosts": [
    "127.0.0.1",
    "192.168.31.44",
    "192.168.31.136",
    "192.168.31.90",
    "${CLUSTER_KUBERNETES_SVC_IP}",
    "kubernetes",
    "kubernetes.default",
    "kubernetes.default.svc",
    "kubernetes.default.svc.cluster",
    "kubernetes.default.svc.cluster.local."
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "opsnull"
    }
  ]
}
EOF

生成证书和私钥：

cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
  -ca-key=/etc/kubernetes/cert/ca-key.pem \
  -config=/etc/kubernetes/cert/ca-config.json \
  -profile=kubernetes kubernetes-csr.json | cfssljson -bare kubernetes
ls kubernetes*pem

分发证书文件：

for node_ip in ${NODE_IPS[@]}
    do
        echo ">>> ${node_ip}"
        scp kubernetes* root@${node_ip}:/etc/kubernetes/cert/
    done

(2) 创建加密配置文件

cd /opt/k8s/work
cat > encryption-config.yaml <<EOF
kind: EncryptionConfig
apiVersion: v1
resources:
  - resources:
      - secrets
    providers:
      - aescbc:
          keys:
            - name: key1
              secret: ${ENCRYPTION_KEY}
      - identity: {}
EOF

将加密配置文件拷贝到 master 节点的 /etc/kubernetes 目录下：

for node_ip in ${NODE_IPS[@]}
    do
        echo ">>> ${node_ip}"
        scp encryption-config.yaml root@${node_ip}:/etc/kubernetes/
    done

(3) 创建审计策略文件

cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
cat > audit-policy.yaml <<EOF
apiVersion: audit.k8s.io/v1beta1
kind: Policy
rules:
  # The following requests were manually identified as high-volume and low-risk, so drop them.
  - level: None
    resources:
      - group: ""
        resources:
          - endpoints
          - services
          - services/status
    users:
      - 'system:kube-proxy'
    verbs:
      - watch

  - level: None
    resources:
      - group: ""
        resources:
          - nodes
          - nodes/status
    userGroups:
      - 'system:nodes'
    verbs:
      - get

  - level: None
    namespaces:
      - kube-system
    resources:
      - group: ""
        resources:
          - endpoints
    users:
      - 'system:kube-controller-manager'
      - 'system:kube-scheduler'
      - 'system:serviceaccount:kube-system:endpoint-controller'
    verbs:
      - get
      - update

  - level: None
    resources:
      - group: ""
        resources:
          - namespaces
          - namespaces/status
          - namespaces/finalize
    users:
      - 'system:apiserver'
    verbs:
      - get

  # Don't log HPA fetching metrics.
  - level: None
    resources:
      - group: metrics.k8s.io
    users:
      - 'system:kube-controller-manager'
    verbs:
      - get
      - list

  # Don't log these read-only URLs.
  - level: None
    nonResourceURLs:
      - '/healthz*'
      - /version
      - '/swagger*'

  # Don't log events requests.
  - level: None
    resources:
      - group: ""
        resources:
          - events

  # node and pod status calls from nodes are high-volume and can be large, don't log responses
  # for expected updates from nodes
  - level: Request
    omitStages:
      - RequestReceived
    resources:
      - group: ""
        resources:
          - nodes/status
          - pods/status
    users:
      - kubelet
      - 'system:node-problem-detector'
      - 'system:serviceaccount:kube-system:node-problem-detector'
    verbs:
      - update
      - patch

  - level: Request
    omitStages:
      - RequestReceived
    resources:
      - group: ""
        resources:
          - nodes/status
          - pods/status
    userGroups:
      - 'system:nodes'
    verbs:
      - update
      - patch

  # deletecollection calls can be large, don't log responses for expected namespace deletions
  - level: Request
    omitStages:
      - RequestReceived
    users:
      - 'system:serviceaccount:kube-system:namespace-controller'
    verbs:
      - deletecollection

  # Secrets, ConfigMaps, and TokenReviews can contain sensitive & binary data,
  # so only log at the Metadata level.
  - level: Metadata
    omitStages:
      - RequestReceived
    resources:
      - group: ""
        resources:
          - secrets
          - configmaps
      - group: authentication.k8s.io
        resources:
          - tokenreviews
  # Get repsonses can be large; skip them.
  - level: Request
    omitStages:
      - RequestReceived
    resources:
      - group: ""
      - group: admissionregistration.k8s.io
      - group: apiextensions.k8s.io
      - group: apiregistration.k8s.io
      - group: apps
      - group: authentication.k8s.io
      - group: authorization.k8s.io
      - group: autoscaling
      - group: batch
      - group: certificates.k8s.io
      - group: extensions
      - group: metrics.k8s.io
      - group: networking.k8s.io
      - group: policy
      - group: rbac.authorization.k8s.io
      - group: scheduling.k8s.io
      - group: settings.k8s.io
      - group: storage.k8s.io
    verbs:
      - get
      - list
      - watch

  # Default level for known APIs
  - level: RequestResponse
    omitStages:
      - RequestReceived
    resources:
      - group: ""
      - group: admissionregistration.k8s.io
      - group: apiextensions.k8s.io
      - group: apiregistration.k8s.io
      - group: apps
      - group: authentication.k8s.io
      - group: authorization.k8s.io
      - group: autoscaling
      - group: batch
      - group: certificates.k8s.io
      - group: extensions
      - group: metrics.k8s.io
      - group: networking.k8s.io
      - group: policy
      - group: rbac.authorization.k8s.io
      - group: scheduling.k8s.io
      - group: settings.k8s.io
      - group: storage.k8s.io

  # Default level for all other requests.
  - level: Metadata
    omitStages:
      - RequestReceived
EOF

分发审计策略文件：

for node_ip in ${NODE_IPS[@]}
    do
        echo ">>> ${node_ip}"
        scp audit-policy.yaml root@${node_ip}:/etc/kubernetes/audit-policy.yaml
    done

(4) 创建后续访问 metrics-server 或 kube-prometheus 使用的证书

cd /opt/k8s/work
cat > proxy-client-csr.json <<EOF
{
  "CN": "aggregator",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "opsnull"
    }
  ]
}
EOF
  • CN 名称需要位于 kube-apiserver 的 --requestheader-allowed-names 参数中，否则后续访问 metrics 时会提示权限不足

生成证书和私钥：

cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
  -ca-key=/etc/kubernetes/cert/ca-key.pem  \
  -config=/etc/kubernetes/cert/ca-config.json  \
  -profile=kubernetes proxy-client-csr.json | cfssljson -bare proxy-client
ls proxy-client*.pem

将生成的证书和私钥文件拷贝到所有 master 节点：

for node_ip in ${NODE_IPS[@]}
    do
        echo ">>> ${node_ip}"
        scp proxy-client* root@${node_ip}:/etc/kubernetes/cert/
    done

(5) 创建 kube-apiserver systemd unit 模板文件

cat > kube-apiserver.service.template <<EOF
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target

[Service]
WorkingDirectory=${K8S_DIR}/kube-apiserver
ExecStart=/opt/k8s/bin/kube-apiserver \\
  --advertise-address=##NODE_IP## \\
  --default-not-ready-toleration-seconds=360 \\
  --default-unreachable-toleration-seconds=360 \\
  --feature-gates=DynamicAuditing=true \\
  --max-mutating-requests-inflight=2000 \\
  --max-requests-inflight=4000 \\
  --default-watch-cache-size=200 \\
  --delete-collection-workers=2 \\
  --encryption-provider-config=/etc/kubernetes/encryption-config.yaml \\
  --etcd-cafile=/etc/kubernetes/cert/ca.pem \\
  --etcd-certfile=/etc/kubernetes/cert/kubernetes.pem \\
  --etcd-keyfile=/etc/kubernetes/cert/kubernetes-key.pem \\
  --etcd-servers=${ETCD_ENDPOINTS} \\
  --bind-address=##NODE_IP## \\
  --secure-port=6443 \\
  --tls-cert-file=/etc/kubernetes/cert/kubernetes.pem \\
  --tls-private-key-file=/etc/kubernetes/cert/kubernetes-key.pem \\
  --insecure-port=0 \\
  --audit-dynamic-configuration \\
  --audit-log-maxage=15 \\
  --audit-log-maxbackup=3 \\
  --audit-log-maxsize=100 \\
  --audit-log-truncate-enabled \\
  --audit-log-path=${K8S_DIR}/kube-apiserver/audit.log \\
  --audit-policy-file=/etc/kubernetes/audit-policy.yaml \\
  --profiling \\
  --anonymous-auth=false \\
  --client-ca-file=/etc/kubernetes/cert/ca.pem \\
  --enable-bootstrap-token-auth \\
  --requestheader-allowed-names="aggregator" \\
  --requestheader-client-ca-file=/etc/kubernetes/cert/ca.pem \\
  --requestheader-extra-headers-prefix="X-Remote-Extra-" \\
  --requestheader-group-headers=X-Remote-Group \\
  --requestheader-username-headers=X-Remote-User \\
  --service-account-key-file=/etc/kubernetes/cert/ca.pem \\
  --authorization-mode=Node,RBAC \\
  --runtime-config=api/all=true \\
  --enable-admission-plugins=NodeRestriction \\
  --allow-privileged=true \\
  --apiserver-count=3 \\
  --event-ttl=168h \\
  --kubelet-certificate-authority=/etc/kubernetes/cert/ca.pem \\
  --kubelet-client-certificate=/etc/kubernetes/cert/kubernetes.pem \\
  --kubelet-client-key=/etc/kubernetes/cert/kubernetes-key.pem \\
  --kubelet-https=true \\
  --kubelet-timeout=10s \\
  --proxy-client-cert-file=/etc/kubernetes/cert/proxy-client.pem \\
  --proxy-client-key-file=/etc/kubernetes/cert/proxy-client-key.pem \\
  --service-cluster-ip-range=${SERVICE_CIDR} \\
  --service-node-port-range=${NODE_PORT_RANGE} \\
  --logtostderr=true \\
  --v=2
Restart=on-failure
RestartSec=10
Type=notify
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF
  • --advertise-address：apiserver 对外通告的 IP（kubernetes 服务后端节点 IP）；
  • --default-*-toleration-seconds：设置节点异常相关的阈值；
  • --max-*-requests-inflight：请求相关的最大阈值；
  • --etcd-*：访问 etcd 的证书和 etcd 服务器地址；
  • --bind-address： https 监听的 IP，不能为 127.0.0.1，否则外界不能访问它的安全端口 6443；
  • --secure-port：https 监听端口；
  • --insecure-port=0：关闭监听 http 非安全端口(8080)；
  • --tls-*-file：指定 apiserver 使用的证书、私钥和 CA 文件；
  • --audit-*：配置审计策略和审计日志文件相关的参数；
  • --client-ca-file：验证 client (kue-controller-manager、kube-scheduler、kubelet、kube-proxy 等)请求所带的证书；
  • --enable-bootstrap-token-auth：启用 kubelet bootstrap 的 token 认证；
  • --requestheader-*：kube-apiserver 的 aggregator layer 相关的配置参数，proxy-client & HPA 需要使用；
  • --requestheader-client-ca-file：用于签名 –proxy-client-cert-file 和 –proxy-client-key-file 指定的证书；在启用了 metric aggregator 时使用；
  • --requestheader-allowed-names：不能为空，值为逗号分割的 –proxy-client-cert-file 证书的 CN 名称，这里设置为 “aggregator”；
  • --service-account-key-file：签名 ServiceAccount Token 的公钥文件，kube-controller-manager 的 –service-account-private-key-file 指定私钥文件，两者配对使用；
  • --runtime-config=api/all=true： 启用所有版本的 APIs，如 autoscaling/v2alpha1；
  • --authorization-mode=Node,RBAC、--anonymous-auth=false： 开启 Node 和 RBAC 授权模式，拒绝未授权的请求；
  • --enable-admission-plugins：启用一些默认关闭的 plugins；
  • --allow-privileged：运行执行 privileged 权限的容器；
  • --apiserver-count=3：指定 apiserver 实例的数量；
  • --event-ttl：指定 events 的保存时间；
  • --kubelet-*：如果指定，则使用 https 访问 kubelet APIs；需要为证书对应的用户(上面 kubernetes*.pem 证书的用户为 kubernetes) 用户定义 RBAC 规则，否则访问 kubelet API 时提示未授权；
  • --proxy-client-*：apiserver 访问 metrics-server 使用的证书；
  • --service-cluster-ip-range： 指定 Service Cluster IP 地址段；
  • --service-node-port-range： 指定 NodePort 的端口范围；

(6) 为各节点创建和分发 kube-apiserver systemd unit 文件

for (( i=0; i < 3; i++ ))
    do
        sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-apiserver.service.template > kube-apiserver-${NODE_IPS[i]}.service 
    done
ls kube-apiserver*.service

分发生成的 systemd unit 文件：

for node_ip in ${NODE_IPS[@]}
    do
        echo ">>> ${node_ip}"
        scp kube-apiserver-${node_ip}.service root@${node_ip}:/etc/systemd/system/kube-apiserver.service
    done

(7) 启动 kube-apiserver 服务

for node_ip in ${NODE_IPS[@]}
    do
        echo ">>> ${node_ip}"
        ssh root@${node_ip} "mkdir -p ${K8S_DIR}/kube-apiserver"
        ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-apiserver && systemctl restart kube-apiserver"
    done

(8) 检查 kube-apiserver 运行状态

for node_ip in ${NODE_IPS[@]}
    do
        echo ">>> ${node_ip}"
        ssh root@${node_ip} "systemctl status kube-apiserver |grep 'Active:'"
    done

(9) 检查集群状态

$ kubectl cluster-info
Kubernetes master is running at https://192.168.31.44:6443

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

$ curl -s --cacert /etc/kubernetes/cert/ca.pem --cert /etc/kubernetes/cert/kubernetes.pem --key /etc/kubernetes/cert/kubernetes-key.pem https://192.168.31.44:6443/healthz
OK

$ kubectl get all --all-namespaces
NAMESPACE   NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
default     service/kubernetes   ClusterIP   10.254.0.1   <none>        443/TCP   7m57s

$ kubectl get componentstatuses
NAME                 STATUS      MESSAGE                                                                                       ERROR
controller-manager   Unhealthy   Get "http://127.0.0.1:10252/healthz": dial tcp 127.0.0.1:10252: connect: connection refused   
scheduler            Unhealthy   Get "http://127.0.0.1:10251/healthz": dial tcp 127.0.0.1:10251: connect: connection refused   
etcd-1               Healthy     {"health":"true"}                                                                             
etcd-0               Healthy     {"health":"true"}                                                                             
etcd-2               Healthy     {"health":"true"}

(10) 检查 kube-apiserver 监听的端口

$ netstat -lnpt | grep kube
tcp        0      0 192.168.31.44:6443     0.0.0.0:*               LISTEN      18018/kube-apiserve
  • 6443: 接收 https 请求的安全端口，对所有请求做认证和授权；
  • 由于关闭了非安全端口，故没有监听 8080；

3. 部署高可用 kube-controller-manager 集群

(1) 创建 kube-controller-manager 证书和私钥

cat > kube-controller-manager-csr.json <<EOF
{
    "CN": "system:kube-controller-manager",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "hosts": [
      "127.0.0.1",
      "192.168.31.44",
      "192.168.31.136",
      "192.168.31.90"
    ],
    "names": [
      {
        "C": "CN",
        "ST": "BeiJing",
        "L": "BeiJing",
        "O": "system:kube-controller-manager",
        "OU": "opsnull"
      }
    ]
}
EOF

生成证书和私钥：

cfssl gencert -ca=/etc/kubernetes/cert/ca.pem \
  -ca-key=/etc/kubernetes/cert/ca-key.pem \
  -config=/etc/kubernetes/cert/ca-config.json \
  -profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager

将生成的证书和私钥分发到所有节点：

for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    scp kube-controller-manager* root@${node_ip}:/etc/kubernetes/cert/
  done

(2) 创建和分发 kubeconfig 文件

kubectl config set-cluster kubernetes \
  --certificate-authority=/etc/kubernetes/cert/ca.pem \
  --embed-certs=true \
  --server="https://##NODE_IP##:6443" \
  --kubeconfig=kube-controller-manager.kubeconfig

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

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

kubectl config use-context system:kube-controller-manager --kubeconfig=kube-controller-manager.kubeconfig

(3) 分发 kubeconfig 到所有节点：

for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    sed -e "s/##NODE_IP##/${node_ip}/" kube-controller-manager.kubeconfig > kube-controller-manager-${node_ip}.kubeconfig
    scp kube-controller-manager-${node_ip}.kubeconfig root@${node_ip}:/etc/kubernetes/kube-controller-manager.kubeconfig
  done

(4) 创建 kube-controller-manager systemd unit 模板文件

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

[Service]
WorkingDirectory=${K8S_DIR}/kube-controller-manager
ExecStart=/opt/k8s/bin/kube-controller-manager \\
  --profiling \\
  --cluster-name=kubernetes \\
  --controllers=*,bootstrapsigner,tokencleaner \\
  --kube-api-qps=1000 \\
  --kube-api-burst=2000 \\
  --leader-elect \\
  --use-service-account-credentials\\
  --concurrent-service-syncs=2 \\
  --bind-address=##NODE_IP## \\
  --tls-cert-file=/etc/kubernetes/cert/kube-controller-manager.pem \\
  --tls-private-key-file=/etc/kubernetes/cert/kube-controller-manager-key.pem \\
  --authentication-kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \\
  --client-ca-file=/etc/kubernetes/cert/ca.pem \\
  --requestheader-allowed-names="aggregator" \\
  --requestheader-client-ca-file=/etc/kubernetes/cert/ca.pem \\
  --requestheader-extra-headers-prefix="X-Remote-Extra-" \\
  --requestheader-group-headers=X-Remote-Group \\
  --requestheader-username-headers=X-Remote-User \\
  --authorization-kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \\
  --cluster-signing-cert-file=/etc/kubernetes/cert/ca.pem \\
  --cluster-signing-key-file=/etc/kubernetes/cert/ca-key.pem \\
  --experimental-cluster-signing-duration=876000h \\
  --horizontal-pod-autoscaler-sync-period=10s \\
  --concurrent-deployment-syncs=10 \\
  --concurrent-gc-syncs=30 \\
  --node-cidr-mask-size=24 \\
  --service-cluster-ip-range=${SERVICE_CIDR} \\
  --pod-eviction-timeout=6m \\
  --terminated-pod-gc-threshold=10000 \\
  --root-ca-file=/etc/kubernetes/cert/ca.pem \\
  --service-account-private-key-file=/etc/kubernetes/cert/ca-key.pem \\
  --kubeconfig=/etc/kubernetes/kube-controller-manager.kubeconfig \\
  --logtostderr=true \\
  --v=2
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF

(5) 为各节点创建和分发 kube-controller-mananger systemd unit 文件

# 替换
for (( i=0; i < 3; i++ ))
  do
    sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-controller-manager.service.template > kube-controller-manager-${NODE_IPS[i]}.service 
  done

# 分发
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    scp kube-controller-manager-${node_ip}.service root@${node_ip}:/etc/systemd/system/kube-controller-manager.service
  done

(6) 启动 kube-controller-manager 服务

for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "mkdir -p ${K8S_DIR}/kube-controller-manager"
    ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-controller-manager && systemctl restart kube-controller-manager"
  done

(7) 检查服务运行状态

for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "systemctl status kube-controller-manager|grep Active"
  done

$ sudo netstat -lnpt | grep kube-controlle
tcp        0      0 192.168.31.44:10257     0.0.0.0:*               LISTEN      8832/kube-controlle 
tcp6       0      0 :::10252                :::*                    LISTEN      8832/kube-controlle

# 10257 端口用于存活性检查
$ curl -s --cacert /etc/kubernetes/cert/ca.pem --cert /etc/kubernetes/cert/kube-controller-manager.pem --key /etc/kubernetes/cert/kube-controller-manager-key.pem https://192.168.31.44:10257/healthz
# 10252 用于与 apiserver 连接

(8) 查看输出的 metrics

$ curl http://192.168.31.44:10252/metrics | head
# TYPE apiserver_audit_event_total counter
apiserver_audit_event_total 0
# HELP apiserver_audit_requests_rejected_total [ALPHA] Counter of apiserver requests rejected due to an error in audit logging backend.
# TYPE apiserver_audit_requests_rejected_total counter
apiserver_audit_requests_rejected_total 0
# HELP apiserver_client_certificate_expiration_seconds [ALPHA] Distribution of the remaining lifetime on the certificate used to authenticate a request.
# TYPE apiserver_client_certificate_expiration_seconds histogram
apiserver_client_certificate_expiration_seconds_bucket{le="0"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="1800"} 0

(9) 查看当前的 leader

$ kubectl get endpoints kube-controller-manager --namespace=kube-system  -o yaml
apiVersion: v1
kind: Endpoints
metadata:
  annotations:
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master_3f327dd8-30f6-45a9-bed9-beb40272ec6e","leaseDurationSeconds":15,"acquireTime":"2020-08-02T03:41:57Z","renewTime":"2020-08-02T03:50:06Z","leaderTransitions":0}'
  creationTimestamp: "2020-08-02T03:41:57Z"
  managedFields:
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:metadata:
        f:annotations:
          .: {}
          f:control-plane.alpha.kubernetes.io/leader: {}
    manager: kube-controller-manager
    operation: Update
    time: "2020-08-02T03:50:06Z"
  name: kube-controller-manager
  namespace: kube-system
  resourceVersion: "13471"
  selfLink: /api/v1/namespaces/kube-system/endpoints/kube-controller-manager
  uid: dac90154-68b7-4d3e-84fc-cdf32e9e3b75

# leader 为 master

4. 部署高可用 kube-scheduler 集群

(1) 创建 kube-scheduler 证书和私钥

cat > kube-scheduler-csr.json <<EOF
{
    "CN": "system:kube-scheduler",
    "hosts": [
      "127.0.0.1",
      "192.168.31.44",
      "192.168.31.136",
      "192.168.31.90"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
      {
        "C": "CN",
        "ST": "BeiJing",
        "L": "BeiJing",
        "O": "system:kube-scheduler",
        "OU": "opsnull"
      }
    ]
}
EOF

生成证书和私钥：

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

分发：

for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    scp kube-scheduler* root@${node_ip}:/etc/kubernetes/cert/
  done

(2) 创建和分发 kubeconfig 文件

kubectl config set-cluster kubernetes \
  --certificate-authority=/etc/kubernetes/cert/ca.pem \
  --embed-certs=true \
  --server="https://##NODE_IP##:6443" \
  --kubeconfig=kube-scheduler.kubeconfig

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

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

kubectl config use-context system:kube-scheduler --kubeconfig=kube-scheduler.kubeconfig

分发：

for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    sed -e "s/##NODE_IP##/${node_ip}/" kube-scheduler.kubeconfig > kube-scheduler-${node_ip}.kubeconfig
    scp kube-scheduler-${node_ip}.kubeconfig root@${node_ip}:/etc/kubernetes/kube-scheduler.kubeconfig
  done

(3) 创建 kube-scheduler 配置文件

cat >kube-scheduler.yaml.template <<EOF
apiVersion: kubescheduler.config.k8s.io/v1alpha1
kind: KubeSchedulerConfiguration
bindTimeoutSeconds: 600
clientConnection:
  burst: 200
  kubeconfig: "/etc/kubernetes/kube-scheduler.kubeconfig"
  qps: 100
enableContentionProfiling: false
enableProfiling: true
hardPodAffinitySymmetricWeight: 1
healthzBindAddress: 127.0.0.1:10251
leaderElection:
  leaderElect: true
metricsBindAddress: 127.0.0.1:10251
EOF

替换模板和分发：

for (( i=0; i < 3; i++ ))
  do
    sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-scheduler.yaml.template > kube-scheduler-${NODE_IPS[i]}.yaml
  done

for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    scp kube-scheduler-${node_ip}.yaml root@${node_ip}:/etc/kubernetes/kube-scheduler.yaml
  done

(4) 创建 kube-scheduler systemd unit 模板文件

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

[Service]
WorkingDirectory=/data/k8s/k8s/kube-scheduler
ExecStart=/opt/k8s/bin/kube-scheduler \
  --config=/etc/kubernetes/kube-scheduler.yaml \
  --tls-cert-file=/etc/kubernetes/cert/kube-scheduler.pem \
  --tls-private-key-file=/etc/kubernetes/cert/kube-scheduler-key.pem \
  --authentication-kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \
  --client-ca-file=/etc/kubernetes/cert/ca.pem \
  --requestheader-allowed-names="" \
  --requestheader-client-ca-file=/etc/kubernetes/cert/ca.pem \
  --requestheader-extra-headers-prefix="X-Remote-Extra-" \
  --requestheader-group-headers=X-Remote-Group \
  --requestheader-username-headers=X-Remote-User \
  --authorization-kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \
  --logtostderr=true \
  --v=2
Restart=always
RestartSec=5
StartLimitInterval=0

[Install]
WantedBy=multi-user.target
EOF

(5) 为各节点创建和分发 kube-scheduler systemd unit 文件

for (( i=0; i < 3; i++ ))
  do
    sed -e "s/##NODE_NAME##/${NODE_NAMES[i]}/" -e "s/##NODE_IP##/${NODE_IPS[i]}/" kube-scheduler.service.template > kube-scheduler-${NODE_IPS[i]}.service 
  done

for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    scp kube-scheduler-${node_ip}.service root@${node_ip}:/etc/systemd/system/kube-scheduler.service
  done

(6) 启动 kube-scheduler 服务

for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "mkdir -p ${K8S_DIR}/kube-scheduler"
    ssh root@${node_ip} "systemctl daemon-reload && systemctl enable kube-scheduler && systemctl restart kube-scheduler"
  done

(7) 检查服务运行状态

for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "systemctl status kube-scheduler|grep Active"
  done

(8) 查看输出的 metrics

$ netstat -lnp | grep schedu
tcp        0      0 127.0.0.1:10251         0.0.0.0:*               LISTEN      16747/kube-schedule 
tcp6       0      0 :::10259                :::*                    LISTEN      16747/kube-schedule 

$ curl http://127.0.0.1:10251/metrics |head
# HELP apiserver_audit_event_total [ALPHA] Counter of audit events generated and sent to the audit backend.
# TYPE apiserver_audit_event_total counter
apiserver_audit_event_total 0
# HELP apiserver_audit_requests_rejected_total [ALPHA] Counter of apiserver requests rejected due to an error in audit logging backend.
# TYPE apiserver_audit_requests_rejected_total counter
apiserver_audit_requests_rejected_total 0
# HELP apiserver_client_certificate_expiration_seconds [ALPHA] Distribution of the remaining lifetime on the certificate used to authenticate a request.
# TYPE apiserver_client_certificate_expiration_seconds histogram
apiserver_client_certificate_expiration_seconds_bucket{le="0"} 0
apiserver_client_certificate_expiration_seconds_bucket{le="1800"} 0

(9) 查看当前的 leader

$ kubectl get endpoints kube-scheduler --namespace=kube-system  -o yaml
apiVersion: v1
kind: Endpoints
metadata:
  annotations:
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"master_ebe08c4d-5d60-4aec-bd45-b75eb3789c41","leaseDurationSeconds":15,"acquireTime":"2020-08-02T09:34:37Z","renewTime":"2020-08-02T09:42:21Z","leaderTransitions":6}'
  creationTimestamp: "2020-08-02T08:46:18Z"
  managedFields:
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:metadata:
        f:annotations:
          .: {}
          f:control-plane.alpha.kubernetes.io/leader: {}
    manager: kube-scheduler
    operation: Update
    time: "2020-08-02T09:42:21Z"
  name: kube-scheduler
  namespace: kube-system
  resourceVersion: "33022"
  selfLink: /api/v1/namespaces/kube-system/endpoints/kube-scheduler
  uid: c36c90f7-358a-4c07-9adb-9db6848a0550

# leader 为 master
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