部署 Dashboard 2.0 + Metrics 监控 Pods node 负载

Kubernetes Dashboard 从v2.0.0-beta1版本开始，集成了一个 metrics-scraper 的组件，可以通过 Kubernetes 的 Metrics API 收集一些基础资源的监控信息，并在web页面展示。

这次就是想用 metrics-scraper

1 使用 openssl 签发证书

mkdir certs
openssl req -nodes -newkey rsa:2048 -keyout certs/dashboard.key -out certs/dashboard.csr -subj "/C=/ST=/L=/O=/OU=/CN=kubernetes-dashboard"
openssl x509 -req -sha256 -days 10000 -in certs/dashboard.csr -signkey certs/dashboard.key -out certs/dashboard.crt

2 安装 Dashboard

# 1 创建 namespace
kubectl create namespace kubernetes-dashboard
# 2 导入证书
kubectl create secret generic kubernetes-dashboard-certs --from-file=certs -n kubernetes-dashboard

# 3 下载部署配置文件  如果下不下来，就自己fq 复制下来
wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-beta3/aio/deploy/recommended.yaml

# 4 注释 recommended.yaml 中的 namespace 
apiVersion: v1
kind: Namespace
metadata:
  name: kubernetes-dashboard


# 5 注释 recommended.yaml 中的 Secret  这几行全部注释
apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-certs
  namespace: kubernetes-dashboard
type: Opaque

# 6 再 args 行 增加 一个 token-ttl 可以延长 token 登陆的过期时间

args:
- --token-ttl=604800

# 7 修改 NodePort 这一部分 替换成 以下 代码 

---

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  type: NodePort
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30000
  selector:
    k8s-app: kubernetes-dashboard

---

# 8 创建
kubectl create -f recommended.yaml

3 创建 serviceAcount 和 token

# 新建 token-user.yaml 
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kube-system


# 创建用户

kubectl create -f token-user.yaml

# 查询 token
kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | grep admin-user | awk '{print $1}')
# 使用 展示 的 token 字符串 登陆 dashboard 

4 安装 metrics-server

metrics-server 是 Kubernetes 官方的集群资源利用率信息收集器，在 k8 1.8 版本 + Heaper 就不再支持了，所以安装 metrics-server

wget https://github.com/kubernetes-incubator/metrics-server/archive/v0.3.3.tar.gz

tar zxvf v0.3.3.tar.gz



# 先等等，这里你直接 安装 可能会有问题 ，我们看下 metrics-server-0.3.3/deploy/1.8+/ 下的 
# metrics-server-deployment.yaml 这个文件 替换成如下的样子
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: metrics-server
  namespace: kube-system
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: metrics-server
  namespace: kube-system
  labels:
    k8s-app: metrics-server
spec:
  selector:
    matchLabels:
      k8s-app: metrics-server
  template:
    metadata:
      name: metrics-server
      labels:
        k8s-app: metrics-server
    spec:
      serviceAccountName: metrics-server
      volumes:
      # mount in tmp so we can safely use from-scratch images and/or read-only containers
      - name: tmp-dir
        emptyDir: {}
      containers:
      - name: metrics-server # 从这里开始替换
#        image: k8s.gcr.io/metrics-server-amd64:v0.3.3
        image: registry.aliyuncs.com/google_containers/metrics-server-amd64:v0.3.3
        args:
          - --kubelet-insecure-tls
          - --kubelet-preferred-address-types=InternalIP
        imagePullPolicy: Always
        volumeMounts:
        - name: tmp-dir
          mountPath: /tmp

执行安装

# 安装
kubectl apply -f metrics-server-0.3.3/deploy/1.8+/

# 查看 metrics server pods 
[root@k8s-master certs]# kubectl -n kube-system get pods -l k8s-app=metrics-server
NAME                              READY   STATUS    RESTARTS   AGE
metrics-server-7745fd5ddd-dn7p6   1/1     Running   0          5h

[root@k8s-master certs]# kubectl get svc -n kube-system metrics-server
NAME             TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)   AGE
metrics-server   ClusterIP   10.96.218.78   <none>        443/TCP   5h

如果你这里 查看 pods 像下面这样：

[root@k8s-master metrics-server-0.3.3]# kubectl -n kube-system get pods -l k8s-app=metrics-server
NAME                             READY   STATUS             RESTARTS   AGE
metrics-server-678cc5687-l2tjn   0/1     ImagePullBackOff   0          5m

# 可以 查看详细/输出/日志信息

[root@k8s-master metrics-server-0.3.3]# kubectl logs -f  metrics-server-7745fd5ddd-dn7p6 -n kube-system

Error from server (BadRequest): container "metrics-server" in pod "metrics-server-678cc5687-l2tjn" is waiting to start: trying and failing to pull image
...
unable to fully scrape metrics from source kubelet_summary:k8s-node1: unable to fetch metrics from Kubelet k8s-node1 (k8s-node1): Get https://k8s-node1:10250/stats/summary/: dial tcp: lookup k8s-node1 on 10.96.0.10:53: no such host]
...
# 这种是 DNS 解析 的异常带来的问题，我们之前配置过的   /etc/hosts

172.16.0.175      k8s-master
172.16.0.100      k8s-node1
172.16.0.147      k8s-node2

# 无法被 metrics-server 所找到 ，这里我们可以添加一个--kubelet-insecure-tls参数跳过证书校验： metrics-server-deployment.yaml 这个文件  

- name: metrics-server
#        image: k8s.gcr.io/metrics-server-amd64:v0.3.3
        image: registry.aliyuncs.com/google_containers/metrics-server-amd64:v0.3.3
        args:
          - --kubelet-insecure-tls
          - --kubelet-preferred-address-types=InternalIP
        #        imagePullPolicy: Always
        imagePullPolicy: Always

重新安装 ，查看日志 ，完成

5 kubectl top nodes 查看效果

[root@k8s-master certs]# kubectl top nodes NAME CPU(cores) CPU% MEMORY(bytes) MEMORY% ecs-ca42 117m 2% 2968Mi 38% k8s-node1 665m 16% 4231Mi 54% k8s-node2 691m 17% 4149Mi 53% k8s-node3 654m 16% 5227Mi 67% k8s-node4 641m 16% 4458Mi 57%

6 打开 dashboard 查看

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