K8S/Kubernetes

概述

已经有了cadvisor、heapster、metric-server，几乎容器运行的所有指标都能拿到，但是下面这种情况却无能为力：

• 我调度了多少个replicas？现在可用的有几个？
• 多少个Pod是running/stopped/terminated状态？
• Pod重启了多少次？
• 我有多少job在运行中

而这些则是kube-state-metrics提供的内容，它基于client-go开发，轮询Kubernetes API，并将Kubernetes的结构化信息转换为metrics。

功能

kube-state-metrics提供的指标，按照阶段分为三种类别：

• 1.实验性质的：k8s api中alpha阶段的或者spec的字段。

• 2.稳定版本的：k8s中不向后兼容的主要版本的更新

• 3.被废弃的：已经不在维护的。

指标类别包括：

• CronJob Metrics
• DaemonSet Metrics
• Deployment Metrics
• Job Metrics
• LimitRange Metrics
• Node Metrics
• PersistentVolume Metrics
• PersistentVolumeClaim Metrics
• Pod Metrics
• Pod Disruption Budget Metrics
• ReplicaSet Metrics
• ReplicationController Metrics
• ResourceQuota Metrics
• Service Metrics
• StatefulSet Metrics
• Namespace Metrics
• Horizontal Pod Autoscaler Metrics
• Endpoint Metrics
• Secret Metrics
• ConfigMap Metrics

以pod为例：

• kube_pod_info
• kube_pod_owner
• kube_pod_status_phase
• kube_pod_status_ready
• kube_pod_status_scheduled
• kube_pod_container_status_waiting
• kube_pod_container_status_terminated_reason
• ...

 

---
apiVersion: rbac.authorization.k8s.io/v1
# kubernetes versions before 1.8.0 should use rbac.authorization.k8s.io/v1beta1
kind: Role
metadata:
  namespace: kube-system
  name: kube-state-metrics-resizer
rules:
- apiGroups: [""]
  resources:
  - pods
  verbs: ["get"]
- apiGroups: ["apps"]
  resources:
  - deployments
  resourceNames: ["kube-state-metrics"]
  verbs: ["get", "update"]
- apiGroups: ["extensions"]
  resources:
  - deployments
  resourceNames: ["kube-state-metrics"]
  verbs: ["get", "update"]
---
apiVersion: rbac.authorization.k8s.io/v1
# kubernetes versions before 1.8.0 should use rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
  name: kube-state-metrics
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: kube-state-metrics-resizer
subjects:
- kind: ServiceAccount
  name: kube-state-metrics
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
# kubernetes versions before 1.8.0 should use rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: kube-state-metrics
rules:
- apiGroups: [""]
  resources:
  - configmaps
  - secrets
  - nodes
  - pods
  - services
  - resourcequotas
  - replicationcontrollers
  - limitranges
  - persistentvolumeclaims
  - persistentvolumes
  - namespaces
  - endpoints
  verbs: ["list", "watch"]
- apiGroups: ["extensions"]
  resources:
  - daemonsets
  - deployments
  - replicasets
  - ingresses
  verbs: ["list", "watch"]
- apiGroups: ["apps"]
  resources:
  - daemonsets
  - deployments
  - replicasets
  - statefulsets
  verbs: ["list", "watch"]
- apiGroups: ["batch"]
  resources:
  - cronjobs
  - jobs
  verbs: ["list", "watch"]
- apiGroups: ["autoscaling"]
  resources:
  - horizontalpodautoscalers
  verbs: ["list", "watch"]
- apiGroups: ["policy"]
  resources:
  - poddisruptionbudgets
  verbs: ["list", "watch"]
- apiGroups: ["certificates.k8s.io"]
  resources:
  - certificatesigningrequests
  verbs: ["list", "watch"]
---
apiVersion: rbac.authorization.k8s.io/v1
# kubernetes versions before 1.8.0 should use rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: kube-state-metrics
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: kube-state-metrics
subjects:
- kind: ServiceAccount
  name: kube-state-metrics
  namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: kube-state-metrics
  namespace: kube-system
---
apiVersion: v1
kind: Service
metadata:
  name: kube-state-metrics
  namespace: kube-system
  labels:
    k8s-app: kube-state-metrics
  annotations:
    prometheus.io/scrape: 'true'
spec:
  ports:
  - name: http-metrics
    port: 8080
    targetPort: http-metrics
    protocol: TCP
  - name: telemetry
    port: 8081
    targetPort: telemetry
    protocol: TCP
  selector:
    k8s-app: kube-state-metrics
---
apiVersion: apps/v1
# Kubernetes version 1.8.x should use apps/v1beta2
# Kubernetes versions before 1.8.0 should use apps/v1beta1 or extensions/v1beta1
kind: Deployment
metadata:
  name: kube-state-metrics
  namespace: kube-system
spec:
  selector:
    matchLabels:
      k8s-app: kube-state-metrics
  replicas: 1
  template:
    metadata:
      labels:
        k8s-app: kube-state-metrics
    spec:
      serviceAccountName: kube-state-metrics
      containers:
      - name: kube-state-metrics
        image: harbor.xxx.cn/3rd_part/kube-state-metrics:v1.6.0
        ports:
        - name: http-metrics
          containerPort: 8080
        - name: telemetry
          containerPort: 8081
        readinessProbe:
          httpGet:
            path: /healthz
            port: 8080
          initialDelaySeconds: 5
          timeoutSeconds: 5
      - name: addon-resizer
        image: harbor.xxx.cn/3rd_part/addon-resizer:1.8.4
        resources:
          limits:
            cpu: 150m
            memory: 50Mi
          requests:
            cpu: 150m
            memory: 50Mi
        env:
          - name: MY_POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: MY_POD_NAMESPACE
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
        command:
          - /pod_nanny
          - --container=kube-state-metrics
          - --cpu=100m
          - --extra-cpu=1m
          - --memory=100Mi
          - --extra-memory=2Mi
          - --threshold=5
          - --deployment=kube-state-metrics