K8S/Kubernetes

安装node-exporter组件，在k8s集群的master1节点操作

cat >node-export.yaml  <<EOF
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: node-exporter
  namespace: monitor-sa
  labels:
    name: node-exporter
spec:
  selector:
    matchLabels:
     name: node-exporter
  template:
    metadata:
      labels:
        name: node-exporter
    spec:
      hostPID: true
      hostIPC: true
      hostNetwork: true
      containers:
      - name: node-exporter
        image: prom/node-exporter:v0.16.0
        ports:
        - containerPort: 9100
        resources:
          requests:
            cpu: 0.15
        securityContext:
          privileged: true
        args:
        - --path.procfs
        - /host/proc
        - --path.sysfs
        - /host/sys
        - --collector.filesystem.ignored-mount-points
        - '"^/(sys|proc|dev|host|etc)($|/)"'
        volumeMounts:
        - name: dev
          mountPath: /host/dev
        - name: proc
          mountPath: /host/proc
        - name: sys
          mountPath: /host/sys
        - name: rootfs
          mountPath: /rootfs
      tolerations:
      - key: "node-role.kubernetes.io/master"
        operator: "Exists"
        effect: "NoSchedule"
      volumes:
        - name: proc
          hostPath:
            path: /proc
        - name: dev
          hostPath:
            path: /dev
        - name: sys
          hostPath:
            path: /sys
        - name: rootfs
          hostPath:
            path: /
EOF

#通过kubectl apply更新node-exporter

kubectl apply -f node-export.yaml

#查看node-exporter是否部署成功

 kubectl get pods -n monitor-sa
显示如下，看到pod的状态都是running，说明部署成功

NAME                  READY   STATUS    RESTARTS   AGE
node-exporter-9qpkd   1/1     Running   0          89s
node-exporter-zqmnk   1/1     Running   0          89s

通过node-exporter采集数据

curl  http://主机ip:9100/metrics
#node-export默认的监听端口是9100，可以看到当前主机获取到的所有监控数据，截取一部分，如下

k8s集群中部署prometheus

1.创建namespace、sa账号，在k8s集群的master节点操作

#创建一个monitor-sa的名称空间

kubectl create ns monitor-sa 

#创建一个sa账号

kubectl create serviceaccount monitor -n monitor-sa  

#把sa账号monitor通过clusterrolebing绑定到clusterrole上

kubectl create clusterrolebinding monitor-clusterrolebinding -n monitor-sa --clusterrole=cluster-admin  --serviceaccount=monitor-sa:monitor

2.创建数据目录

#在k8s集群的任何一个node节点操作，因为我的k8s集群只有一个node节点node1，所以我在node1上操作如下命令：

mkdir /data
chmod 777 /data/

3.安装prometheus，以下步骤均在在k8s集群的master1节点操作

1)创建一个configmap存储卷，用来存放prometheus配置信息

cat  >prometheus-cfg.yaml <<EOF
---
kind: ConfigMap
apiVersion: v1
metadata:
  labels:
    app: prometheus
  name: prometheus-config
  namespace: monitor-sa
data:
  prometheus.yml: |
    global:
      scrape_interval: 15s
      scrape_timeout: 10s
      evaluation_interval: 1m
    scrape_configs:
    - job_name: 'kubernetes-node'
      kubernetes_sd_configs:
      - role: node
      relabel_configs:
      - source_labels: [__address__]
        regex: '(.*):10250'
        replacement: '${1}:9100'
        target_label: __address__
        action: replace
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.+)
    - job_name: 'kubernetes-node-cadvisor'
      kubernetes_sd_configs:
      - role:  node
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      relabel_configs:
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.+)
      - target_label: __address__
        replacement: kubernetes.default.svc:443
      - source_labels: [__meta_kubernetes_node_name]
        regex: (.+)
        target_label: __metrics_path__
        replacement: /api/v1/nodes/${1}/proxy/metrics/cadvisor
    - job_name: 'kubernetes-apiserver'
      kubernetes_sd_configs:
      - role: endpoints
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      relabel_configs:
      - source_labels: [__meta_kubernetes_namespace, __meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]
        action: keep
        regex: default;kubernetes;https
    - job_name: 'kubernetes-service-endpoints'
      kubernetes_sd_configs:
      - role: endpoints
      relabel_configs:
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]
        action: keep
        regex: true
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scheme]
        action: replace
        target_label: __scheme__
        regex: (https?)
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_path]
        action: replace
        target_label: __metrics_path__
        regex: (.+)
      - source_labels: [__address__, __meta_kubernetes_service_annotation_prometheus_io_port]
        action: replace
        target_label: __address__
        regex: ([^:]+)(?::\d+)?;(\d+)
        replacement: $1:$2
      - action: labelmap
        regex: __meta_kubernetes_service_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        action: replace
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_service_name]
        action: replace
        target_label: kubernetes_name 
EOF

 注意：通过上面命令生成的promtheus-cfg.yaml文件会有一些问题，$1和$2这种变量在文件里没有，需要在k8s的master1节点打开promtheus-cfg.yaml文件，手动把$1和$2这种变量写进文件里，promtheus-cfg.yaml文件需要手动修改部分如下：

 22行的replacement: ':9100'变成replacement: '${1}:9100'

42行的replacement: /api/v1/nodes//proxy/metrics/cadvisor变成  replacement: /api/v1/nodes/${1}/proxy/metrics/cadvisor

73行的replacement:  变成replacement: $1:$2

#通过kubectl apply更新configmap

kubectl apply  -f  prometheus-cfg.yaml

2)通过deployment部署prometheus

cat  >prometheus-deploy.yaml <<EOF
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: prometheus-server
  namespace: monitor-sa
  labels:
    app: prometheus
spec:
  replicas: 1
  selector:
    matchLabels:
      app: prometheus
      component: server
    #matchExpressions:
    #- {key: app, operator: In, values: [prometheus]}
    #- {key: component, operator: In, values: [server]}
  template:
    metadata:
      labels:
        app: prometheus
        component: server
      annotations:
        prometheus.io/scrape: 'false'
    spec:
      nodeName: node1
      serviceAccountName: monitor
      containers:
      - name: prometheus
        image: prom/prometheus:v2.2.1
        imagePullPolicy: IfNotPresent
        command:
          - prometheus
          - --config.file=/etc/prometheus/prometheus.yml
          - --storage.tsdb.path=/prometheus
          - --storage.tsdb.retention=720h
        ports:
        - containerPort: 9090
          protocol: TCP
        volumeMounts:
        - mountPath: /etc/prometheus/prometheus.yml
          name: prometheus-config
          subPath: prometheus.yml
        - mountPath: /prometheus/
          name: prometheus-storage-volume
      volumes:
        - name: prometheus-config
          configMap:
            name: prometheus-config
            items:
              - key: prometheus.yml
                path: prometheus.yml
                mode: 0644
        - name: prometheus-storage-volume
          hostPath:
           path: /data
           type: Directory
EOF

注意：在上面的prometheus-deploy.yaml文件有个nodeName字段，这个就是用来指定创建的这个prometheus的pod调度到哪个节点上，我们这里让nodeName=node1，也即是让pod调度到node1节点上，因为node1节点我们创建了数据目录/data，所以大家记住：你在k8s集群的哪个节点创建/data，就让pod调度到哪个节点。

#通过kubectl apply更新prometheus

kubectl apply -f prometheus-deploy.yaml

#查看prometheus是否部署成功

kubectl get pods -n monitor-sa

显示如下，可看到pod状态是running，说明prometheus部署成功

NAME                                 READY   STATUS    RESTARTS   AGE
node-exporter-9qpkd                  1/1     Running   0          76m
node-exporter-zqmnk                  1/1     Running   0          76m
prometheus-server-85dbc6c7f7-nsg94   1/1     Running   0          6m7

 3)给prometheus pod创建一个service

cat  > prometheus-svc.yaml << EOF
---
apiVersion: v1
kind: Service
metadata:
  name: prometheus
  namespace: monitor-sa
  labels:
    app: prometheus
spec:
  type: NodePort
  ports:
    - port: 9090
      targetPort: 9090
      protocol: TCP
  selector:
    app: prometheus
    component: server
EOF

#通过kubectl apply 更新service

kubectl  apply -f prometheus-svc.yaml

#查看service在物理机映射的端口

kubectl get svc -n monitor-sa

显示如下：

NAME         TYPE       CLUSTER-IP    EXTERNAL-IP   PORT(S)          AGE
prometheus   NodePort   10.96.45.93   <none>        9090:31043/TCP   50s

通过上面可以看到service在宿主机上映射的端口是31043，这样我们访问k8s集群的master1节点的ip:31043，就可以访问到prometheus的web ui界面了

#访问prometheus web ui界面

火狐浏览器输入如下地址：

http://192.168.0.6:31043/graph

可看到如下页面：

 #点击页面的Status->Targets，可看到如下,说明我们配置的服务发现可以正常采集数据

#为了每次修改配置文件可以热加载prometheus，也就是不停止prometheus，就可以使配置生效，如修改prometheus-cfg.yaml，想要使配置生效可用如下热加载命令：
curl -X POST http://10.244.1.66:9090/-/reload

#10.244.1.66是prometheus的pod的ip地址，如何查看prometheus的pod ip，可用如下命令：

kubectl get pods -n monitor-sa -o wide | grep prometheus

显示如下， 10.244.1.7就是prometheus的ip

prometheus-server-85dbc6c7f7-nsg94   1/1     Running   0          29m   10.244.1.7     node

#热加载速度比较慢，可以暴力重启prometheus，如修改上面的prometheus-cfg.yaml文件之后，可执行如下强制删除：

kubectl delete -f prometheus-cfg.yaml

kubectl delete -f prometheus-deploy.yaml

然后再通过apply更新：

kubectl apply -f prometheus-cfg.yaml

kubectl apply -f prometheus-deploy.yaml

注意：

线上最好热加载，暴力删除可能造成监控数据的丢失