如何快速实现Prometheus监控Kubernetes集群

Prometheus

K8S集群中常见的监控工具有哪些:

• Kubernetes Dashboard
• Kube-monkey
• K8s-testsuite
• Kubespray
• Minikube
• Prometheus

K8S集群监控-外部

| apiserver 访问 |

| -------------- |

集群外部访问：

• 通过public IPs访问service
• 通过proxy 访问node、pod、service
• 通过集群内的node或pod间接访问

查看 kube-system 命名空间的 proxy url：

$ kubectl cluster-info

Kubernetes control plane is running at https://192.168.50.160:6443
CoreDNS is running at https://192.168.50.160:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

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

其默认的构造规则为：

# 访问node
https://${other_apiserver_address}/api/v1/nodes/node_name:[port_name]/proxy/metrics
# 访问service
https://${other_apiserver_address}/api/v1/namespaces/service_namespace/services/http:service_name[:port_name]/proxy/metrics
# 访问pod
https://${other_apiserver_address}/api/v1/namespaces/pod_namespace/pods/http:pod_name[:port_name]/proxy/metrics

apiserver授权

集群外访问需要使用token+客户端cert进行认证方案，需要先进行RBAC授权。

创建 prometheus 用户，并绑定cluster-admin角色：

# 创建命名空间
$ kubectl create ns devops
# 创建serviceaccounts
$ kubectl create sa  prometheus -n devops
# 整个集群范围，将名为 cluster-admin 的 ClusterRole 与 devops:prometheus sa绑定，devops:prometheus 具有 cluster-admin 定义的权限
$ kubectl create clusterrolebinding prometheus --clusterrole cluster-admin --serviceaccount=devops:prometheus

构造token：

访问 apiserver 不是直接使用 serviceaccount，而是通过 token。

我们需要获取 serviceaccount:prometheus 对应的 token.

$ kubectl create token prometheus -n devops
eyJhbGciOiJSUzI1NiIsImtpZCI6IkJvUWREbFI1Y2FZcV9JWXBoV3BCTUVyRHE5ZUtVenFXekRzb0ttNllPVFEifQ.eyJhdWQiOlsiaHR0cHM6Ly9rdWJlcm5ldGVzLmRlZmF1bHQuc3ZjLmNsdXN0ZXIubG9jYWwiXSwiZXhwIjoxNjkzMjk0NzMxLCJpYXQiOjE2OTMyOTExMzEsImlzcyI6Imh0dHBzOi8va3ViZXJuZXRlcy5kZWZhdWx0LnN2Yy5jbHVzdGVyLmxvY2FsIiwia3ViZXJuZXRlcy5pbyI6eyJuYW1lc3BhY2UiOiJkZXZvcHMiLCJzZXJ2aWNlYWNjb3VudCI6eyJuYW1lIjoicHJvbWV0aGV1cyIsInVpZCI6ImZjMzU4NGUxLWQ5NDItNGY0My1hN2Q2LTYxMWMyY2M4NWI0NCJ9fSwibmJmIjoxNjkzMjkxMTMxLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6ZGV2b3BzOnByb21ldGhldXMifQ.FhUo4dcHAYCoKUF-GlN1PvCT40BKJ-DfPy_Bxju8H5GyzD_A7fQyjputEl4VG33ckcYYdRI4uNzvrTU2k4HGojzZASCwqVSHmoH4wvdPsKIVq521G-cq0wfP6mPDnzYx4p2UlqLxpg7-6IBbjFhzKrPRLDEuBmHRnQn77etcv9RXVa2mqoalxrt5VLE7f-8aLIPCBSpzoayRppQDQvpJxZ45Bz5lfId5zY_3topSAwo-by6X-BBNVBQLy2evjKc80M_ne8VWi9GygKtuRVpzNMxq3t8DQOE0VCaPWLB90CcZD_Y2pi63uzwS0N-ikmKB1Rps3xCmO4kKFUm3h6crvg

访问测试：

$ curl -k -H 'Authorization: Bearer TOKEN' https://192.168.50.160:6443/api
{
	"kind": "APIVersions",
	"versions": [
		"v1"
	],
	"serverAddressByClientCIDRs": [
		{
			"clientCIDR": "0.0.0.0/0",
			"serverAddress": "192.168.50.160:6443"
		}
	]
}

检测目标

• kubelet 监控
• 资源

Kubelet监控

kubelet会输出一些监控指标数据，通过：

https://NodeIP:10250/metrics

地址可以访问到。

cAdvisor 是一个开源的分析容器资源使用率和性能特性的代理工具，集成到 Kubelet中，当Kubelet启动时会同时启动cAdvisor，且一个cAdvisor只监控一个Node节点的信息。cAdvisor 自动查找所有在其所在节点上的容器，自动采集 CPU、内存、文件系统和网络使用的统计信息。cAdvisor 通过它所在节点机的 Root 容器，采集并分析该节点机的全面使用情况。通过：

https://NodeIP:10250/metrics/cadvisor

可以访问到。

K8S资源对象

kube-state-metrics 是一个服务，它监听 Kubernetes APIServer 并生成关联对象的metrics，包括：Node、Service、Pod、Endpoints、Ingress。

# 下载部署文件
wget https://raw.githubusercontent.com/kubernetes/kube-state-metrics/main/examples/standard/service-account.yaml
wget https://raw.githubusercontent.com/kubernetes/kube-state-metrics/main/examples/standard/cluster-role.yaml
wget https://raw.githubusercontent.com/kubernetes/kube-state-metrics/main/examples/standard/cluster-role-binding.yaml
wget https://raw.githubusercontent.com/kubernetes/kube-state-metrics/main/examples/standard/deployment.yaml
wget https://raw.githubusercontent.com/kubernetes/kube-state-metrics/main/examples/standard/service.yaml

# 部署

kubectl apply -f service-account.yaml
kubectl apply -f cluster-role.yaml
kubectl apply -f cluster-role-binding.yaml
kubectl apply -f deployment.yaml
kubectl apply -f service.yaml

# 结果：
$ kubectl get pods -n kube-system | grep kube-state-metrics
kube-state-metrics-59b487664-trpjx     1/1     Running   0             19h
$ kubectl get services -n kube-system | grep kube-state-metrics
kube-state-metrics   ClusterIP   None         <none>        8080/TCP,8081/TCP        19h

Node指标：

部署 node_exporter 实现，可以单独部署在node服务器上，但推荐使用 DaemonSet 形式部署在K8S集群中，可以配合Prometheus的动态服务发现使用：

# node-exporter.yaml
kind: DaemonSet
apiVersion: apps/v1
metadata:
  name: node-exporter
  namespace: monitor
  annotations:
    prometheus.io/scrape: 'true'
spec:
  selector:
    matchLabels:
      app: node-exporter
  template:
    metadata:
      labels:
        app: node-exporter
      name: node-exporter
    spec:
      containers:
      - image: quay.io/prometheus/node-exporter:latest
        name: node-exporter
        ports:
        - containerPort: 9100
          hostPort: 9100
          name: node-exporter
      hostNetwork: true
      hostPID: true
      tolerations:
      - key: "node-role.kubernetes.io/master"
        operator: "Exists"
        effect: "NoSchedule"
kind: Service
apiVersion: v1
metadata:
  annotations:
    prometheus.io/scrape: 'true'
  labels:
    app: node-exporter
  name: node-exporter
spec:
  type: ClusterIP
  clusterIP: None
  ports:
  - name: node-exporter
    port: 9100
    protocol: TCP
  selector:
    app: node-exporter

部署：

$ kubectl create namespace monitor
$ kubectl apply -f node-exporter.yaml

Prometheus服务发现

Kubelet监控服务发现

增加两个job：

# prometheus.yaml

  - job_name: "kube-node-kubelet"
    scheme: https
    tls_config:
      insecure_skip_verify: true
    bearer_token_file: /prometheus/k8s_token #使用 token 值，以文件形式存储
    kubernetes_sd_configs: # k8s 服务发现配置
    # 使用endpoint级别自动发现
    - role: node
      api_server: "https://192.168.50.160:6443"
      tls_config:
        insecure_skip_verify: true
      bearer_token_file: /prometheus/k8s_token

    relabel_configs:
      # 将标签(.*)作为新标签名，原有值不变
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.*)
      # 修改NodeIP:10250为APIServerIP:6443
      - action: replace
        regex: (.*)
        source_labels: [ __address__ ]
        target_label: __address__
        replacement: 192.168.50.160:6443
      # 实际访问指标接口 https://NodeIP:10250/metrics 这个接口只能APISERVER访问，故此重新标记标签使用APISERVER代理访问
      - action: replace
        source_labels: [ __meta_kubernetes_node_name ]
        target_label: __metrics_path__
        regex: (.*)
        replacement: /api/v1/nodes/${1}/proxy/metrics
  - job_name: "kube-node-cadvisor"
    scheme: https
    tls_config:
      insecure_skip_verify: true
    #使用apiserver授权部分解密的token值，以文件形式存储
    bearer_token_file: /prometheus/k8s_token
    # k8s自动发现具体配置
    kubernetes_sd_configs:
      # 使用endpoint级别自动发现
      - role: node
        api_server: "https://192.168.50.160:6443"
        tls_config:
          insecure_skip_verify: true
        bearer_token_file: /prometheus/k8s_token
    relabel_configs:
      # 将标签(.*)作为新标签名，原有值不变
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.*)
      # 修改NodeIP:10250为APIServerIP:6443
      - action: replace
        regex: (.*)
        source_labels: [ __address__ ]
        target_label: __address__
        replacement: 192.168.50.160:6443
      # 实际访问指标接口 https://NodeIP:10250/metrics/cadvisor 这个接口只能APISERVER访问，故此重新标记标签使用APISERVER代理访问
      - action: replace
        source_labels: [ __meta_kubernetes_node_name ]
        target_label: __metrics_path__
        regex: (.*)
        replacement: /api/v1/nodes/${1}/proxy/metrics/cadvisor

/prometheus/k8s_token 文件配合容器的volume，基于k8s生成后，拷贝到数据卷中。

kubelet relabel_configs：

label	default	relabel
__scheme__	https	https
__address__	master-node-IP:10250	master-node-IP:6443
__metrics_path__	/metrics	/api/v1/nodes/node-name/proxy/metrics
URL	https://192.168.50.160:10250/metrics	https://192.168.50.160:6443/api/v1/nodes/k8s-worker01/proxy/metrics

kubelet advisor relabel_configs：

label	default	relabel
__scheme__	https	https
__address__	master-node-IP:10250	master-node-IP:6443
__metrics_path__	/metrics/cadvisor	/api/v1/nodes/node-name/proxy/metrics/cadvisor
URL	https://192.168.50.160:10250/metrics/cadvisor	https://192.168.50.160:6443/api/v1/nodes/k8s-worker01/proxy/metrics/cadvisor

K8S资源对象服务发现

增加一个job

# prometheus.yaml

  - job_name: "kube-state-metrics"
    scheme: https
    tls_config:
      insecure_skip_verify: true
    #使用apiserver授权部分解密的token值，以文件形式存储
    bearer_token_file: /prometheus/k8s_token
    # k8s自动发现具体配置
    kubernetes_sd_configs:
      - role: endpoints
        api_server: "https://192.168.50.160:6443"
        tls_config:
          insecure_skip_verify: true
        bearer_token_file: /prometheus/k8s_token
    relabel_configs:
      - action: keep
        source_labels: [ __meta_kubernetes_service_name ]
        regex: '^(kube-state-metrics)$'
      # 将标签(.*)作为新标签名，原有值不变
      - action: labelmap
        regex: __meta_kubernetes_service_label_(.*)
      # 修改NodeIP:10250为APIServerIP:6443
      - action: replace
        regex: (.*)
        source_labels: [ __address__ ]
        target_label: __address__
        replacement: 192.168.50.160:6443
      # 实际访问指标接口
      - action: replace
        source_labels: [ __meta_kubernetes_namespace, __meta_kubernetes_pod_name, __meta_kubernetes_pod_container_port_number ]
        target_label: __metrics_path__
        regex: ([^;]+);([^;]+);([^;]+)
        replacement: /api/v1/namespaces/${1}/pods/http:${2}:${3}/proxy/metrics

kube-state-metrics relabel_configs：

label	default	relabel
__scheme__	https	https
__address__	cluster-internal-IP:8081	master-node-IP:6443
__metrics_path__	/metrics	/api/v1/namespaces/kube-system/pods/http:kube-state-metrics-59b487664-trpjx:8081/proxy/metrics
URL	https://cluster-internal-IP:8081/metrics	https://192.168.50.160:6443//api/v1/namespaces/kube-system/pods/http:kube-state-metrics-59b487664-trpjx:8081/proxy/metrics

启动 prometheus

docker-compose 方案：

# docker-composer.yaml
version: '3'
services:
  prometheus:
    image: prom/prometheus
    container_name: prometheus
    restart: always
    ports:
      - "9090:9090"
    volumes:
      - ./etc/prometheus.yml:/etc/prometheus/prometheus.yml
      - ./data:/prometheus
    command:
      - '--config.file=/etc/prometheus/prometheus.yml'
      - '--storage.tsdb.path=/prometheus'
      - '--web.console.libraries=/usr/share/prometheus/console_libraries'
      - '--web.console.templates=/usr/share/prometheus/consoles'
      - '--web.external-url=http://192.168.1.200:9090/'
      - '--web.enable-lifecycle'
      - '--storage.tsdb.retention=15d'

访问 prometheus ui，查看target

http://localhost:9090/targets?search=

Granfana

docker 启动：

docker run --name myGrafana -d -p 3000:3000 grafana/grafana

配置数据源：prometheus

选择DashBoard，示例ID：8588

需要适当编辑具体的panel。

K8S集群监控-内部