kubernetes资源监控(Metrics-Server部署+Dashboard部署)

1.Metrics-Server介绍

Metrics-Server是集群核心监控数据的聚合器，用来替换之前的heapster。
• 容器相关的 Metrics 主要来自于 kubelet 内置的 cAdvisor 服务，有了MetricsServer之后，用户就可以通过标准的 Kubernetes API 来访问到这些监控数据。
• Metrics API 只可以查询当前的度量数据，并不保存历史数据。
• Metrics API URI 为 /apis/metrics.k8s.io/，在 k8s.io/metrics 维护。
• 必须部署 metrics-server 才能使用该 API，metrics-server 通过调用 Kubelet Summary API 获取数据。
示例：
http://127.0.0.1:8001/apis/metrics.k8s.io/v1beta1/nodes
http://127.0.0.1:8001/apis/metrics.k8s.io/v1beta1/nodes/<node-name> http://127.0.0.1:8001/apis/metrics.k8s.io/v1beta1/namespace/<namespacename>/pods/<pod-name>

Metrics Server 并不是 kube-apiserver 的一部分，而是通过 Aggregator 这种插件机制，在独立部署的情况下同 kube-apiserver 一起统一对外服务的。
• kube-aggregator 其实就是一个根据 URL 选择具体的 API 后端的代理服务器。

Metrics-server属于Core metrics(核心指标)，提供API metrics.k8s.io，仅提供Node和Pod的 CPU和内存使用情况。而其他Custom Metrics(自定义指标)由Prometheus等组件来完成。

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2.Metrics-Server部署

官方参考：https://github.com/kubernetes-incubator/metrics-server

1.安装Metrics-Server

[kubeadm@server1 ms]$ wget https://github.com/kubernetes-sigs/metrics-server/releases/download/v0.3.6/components.yaml
--2020-07-04 23:31:40--  https://github.com/kubernetes-sigs/metrics-server/releases/download/v0.3.6/components.yaml
Resolving github.com (github.com)... 13.250.177.223
Connecting to github.com (github.com)|13.250.177.223|:443... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://github-production-release-asset-2e65be.s3.amazonaws.com/92132038/cf781b00-7752-11ea-9faf-0b397e7b8445?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20200704%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20200704T073144Z&X-Amz-Expires=300&X-Amz-Signature=cda43d47c725cd844bc7c7c10cf5c3e9d655fa5a6f61522c1fa67e8664df9449&X-Amz-SignedHeaders=host&actor_id=0&repo_id=92132038&response-content-disposition=attachment%3B%20filename%3Dcomponents.yaml&response-content-type=application%2Foctet-stream [following]
--2020-07-04 23:31:42--  https://github-production-release-asset-2e65be.s3.amazonaws.com/92132038/cf781b00-7752-11ea-9faf-0b397e7b8445?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20200704%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20200704T073144Z&X-Amz-Expires=300&X-Amz-Signature=cda43d47c725cd844bc7c7c10cf5c3e9d655fa5a6f61522c1fa67e8664df9449&X-Amz-SignedHeaders=host&actor_id=0&repo_id=92132038&response-content-disposition=attachment%3B%20filename%3Dcomponents.yaml&response-content-type=application%2Foctet-stream
Resolving github-production-release-asset-2e65be.s3.amazonaws.com (github-production-release-asset-2e65be.s3.amazonaws.com)... 52.216.113.203
Connecting to github-production-release-asset-2e65be.s3.amazonaws.com (github-production-release-asset-2e65be.s3.amazonaws.com)|52.216.113.203|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 3335 (3.3K) [application/octet-stream]
Saving to: ‘components.yaml’
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