Prometheus Operator 監控Kubernetes

1. Prometheus的基本架構

​ Prometheus是一個開源的完整監控解決方案，涵蓋資料採集、查詢、告警、展示整個監控流程，下圖是Prometheus的架構圖：

官方文件：https://prometheus.io/docs/introduction/overview/

2. 元件說明

Prometheus生態系統由多個元件組成。其中許多元件都是可選的

• Promethus  server

必須安裝，本質是一個時序資料庫，主要負責資料pull、儲存、分析，提供 PromQL 查詢語言的支援；

• Push Gateway

非必選項，支援臨時性Job主動推送指標的中間閘道器

• exporters

部署在客戶端的agent,如 node_exporte, mysql_exporter等

提供被監控元件資訊的 HTTP 介面被叫做 exporter ，目前網際網路公司常用的元件大部分都有 exporter 可以直接使用，比如 Varnish、Haproxy、Nginx、MySQL、Linux 系統資訊 (包括磁碟、記憶體、CPU、網路等等)；如：https://prometheus.io/docs/instrumenting/exporters/

• alertmanager

用來進行報警，Promethus server 經過分析， 把出發的警報傳送給 alertmanager 元件，alertmanager 元件通過自身的規則，來發送通知,(郵件，或者webhook)

3. Prometheus-Operator

Prometheus-Operator的架構圖：

上圖是Prometheus-Operator官方提供的架構圖，其中Operator是最核心的部分，作為一個控制器，他會去建立Prometheus、ServiceMonitor、AlertManager以及PrometheusRule4個CRD資源物件，然後會一直監控並維持這4個資源物件的狀態。

其中建立的prometheus這種資源物件就是作為Prometheus Server存在，而ServiceMonitor就是exporter的各種抽象，exporter前面我們已經學習了，是用來提供專門提供metrics資料介面的工具，Prometheus就是通過ServiceMonitor提供的metrics資料介面去 pull 資料的，當然alertmanager這種資源物件就是對應的AlertManager的抽象，而PrometheusRule是用來被Prometheus例項使用的報警規則檔案。

這樣我們要在叢集中監控什麼資料，就變成了直接去操作 Kubernetes 叢集的資源物件了，是不是方便很多了。上圖中的 Service 和 ServiceMonitor 都是 Kubernetes 的資源，一個 ServiceMonitor 可以通過 labelSelector 的方式去匹配一類 Service，Prometheus 也可以通過 labelSelector 去匹配多個ServiceMonitor。

4. Prometheus-Operator部署

官方chart地址：https://github.com/helm/charts/tree/master/stable/prometheus-operator

搜尋最新包下載到本地

# 搜尋

helm search prometheus-operator

NAME                            CHART VERSION   APP VERSION     DESCRIPTION                                
stable/prometheus-operator      6.4.0           0.31.0          Provides easy monitoring definitions for Kubernetes servi...

# 拉取到本地

helm fetch prometheus-operator

安裝

# 新建一個monitoring的namespaces

Kubectl create ns monitoring

# 安裝

helm install -f ./prometheus-operator/values.yaml --name prometheus-operator --namespace=monitoring ./prometheus-operator

# 更新

helm upgrade -f prometheus-operator/values.yaml prometheus-operator ./prometheus-operator

解除安裝prometheus-operator

helm delete prometheus-operator --purge

# 刪除crd

kubectl delete customresourcedefinitions prometheuses.monitoring.coreos.com prometheusrules.monitoring.coreos.com servicemonitors.monitoring.coreos.com
kubectl delete customresourcedefinitions alertmanagers.monitoring.coreos.com
kubectl delete customresourcedefinitions podmonitors.monitoring.coreos.com

修改配置文件values.yaml

4.1. 郵件告警

  config:

    global:

      resolve_timeout: 5m

      smtp_smarthost: 'smtp.qq.com:465'

      smtp_from: '[email protected]'

      smtp_auth_username: '[email protected]'

      smtp_auth_password: 'xreqcqffrxtnieff'

      smtp_hello: '163.com'

      smtp_require_tls: false

    route:

      group_by: ['job','severity']

      group_wait: 30s

      group_interval: 1m

      repeat_interval: 12h

      receiver: default

      routes:

      - receiver: webhook

        match:

          alertname: TargetDown

    receivers:

    - name: default

      email_configs:

      - to: '[email protected]'

        send_resolved: true

    - name: webhook

      email_configs:

      - to: '[email protected]'

        send_resolved: true

這裡有個坑請參考：https://www.cnblogs.com/Dev0ps/p/11320177.html

4.2. prometheus持久化儲存

  storage:

      volumeClaimTemplate:

        spec:

          storageClassName: nfs-client

          accessModes: ["ReadWriteOnce"]

          resources:

            requests:

              storage: 50Gi

4.3. Grafana持久化

路徑：prometheus-operator/charts/grafana/values.yaml

persistence:

  enabled: true

  storageClassName: "nfs-client"

  accessModes:

    - ReadWriteOnce

  size: 10Gi

4.4. 自動發現Service

     - 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

     - job_name: 'kubernetes-pod'

       kubernetes_sd_configs:

         - role: pod

       relabel_configs:

       - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]

         action: keep

         regex: true

       - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]

         action: replace

         target_label: __metrics_path__

         regex: (.+)

       - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]

         action: replace

         regex: ([^:]+)(?::\d+)?;(\d+)

         replacement: $1:$2

         target_label: __address__

       - action: labelmap

         regex: __meta_kubernetes_pod_label_(.+)

       - source_labels: [__meta_kubernetes_namespace]

         action: replace

         target_label: kubernetes_namespace

       - source_labels: [__meta_kubernetes_pod_name]

         action: replace

         target_label: kubernetes_pod_name

     - job_name: istio-mesh

       scrape_interval: 15s

       scrape_timeout: 10s

       metrics_path: /metrics

       scheme: http

       kubernetes_sd_configs:

       - api_server: null

         role: endpoints

         namespaces:

           names:

           - istio-system

       relabel_configs:

       - source_labels: [__meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]

         separator: ;

         regex: istio-telemetry;prometheus

         replacement: $1

         action: keep

     - job_name: envoy-stats

       scrape_interval: 15s

       scrape_timeout: 10s

       metrics_path: /stats/prometheus

       scheme: http

       kubernetes_sd_configs:

       - api_server: null

         role: pod

         namespaces:

           names: []

       relabel_configs:

       - source_labels: [__meta_kubernetes_pod_container_port_name]

         separator: ;

         regex: .*-envoy-prom

         replacement: $1

         action: keep

       - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]

         separator: ;

         regex: ([^:]+)(?::\d+)?;(\d+)

         target_label: __address__

         replacement: $1:15090

         action: replace

       - separator: ;

         regex: __meta_kubernetes_pod_label_(.+)

         replacement: $1

         action: labelmap

       - source_labels: [__meta_kubernetes_namespace]

         separator: ;

         regex: (.*)

         target_label: namespace

         replacement: $1

         action: replace

       - source_labels: [__meta_kubernetes_pod_name]

         separator: ;

         regex: (.*)

         target_label: pod_name

         replacement: $1

         action: replace

       metric_relabel_configs:

       - source_labels: [cluster_name]

         separator: ;

         regex: (outbound|inbound|prometheus_stats).*

         replacement: $1

         action: drop

       - source_labels: [tcp_prefix]

         separator: ;

         regex: (outbound|inbound|prometheus_stats).*

         replacement: $1

         action: drop

       - source_labels: [listener_address]

         separator: ;

         regex: (.+)

         replacement: $1

         action: drop

       - source_labels: [http_conn_manager_listener_prefix]

         separator: ;

         regex: (.+)

         replacement: $1

         action: drop

       - source_labels: [http_conn_manager_prefix]

         separator: ;

         regex: (.+)

         replacement: $1

         action: drop

       - source_labels: [__name__]

         separator: ;

         regex: envoy_tls.*

         replacement: $1

         action: drop

       - source_labels: [__name__]

         separator: ;

         regex: envoy_tcp_downstream.*

         replacement: $1

         action: drop

       - source_labels: [__name__]

         separator: ;

         regex: envoy_http_(stats|admin).*

         replacement: $1

         action: drop

       - source_labels: [__name__]

         separator: ;

         regex: envoy_cluster_(lb|retry|bind|internal|max|original).*

         replacement: $1

         action: drop

     - job_name: istio-policy

       scrape_interval: 15s

       scrape_timeout: 10s

       metrics_path: /metrics

       scheme: http

       kubernetes_sd_configs:

       - api_server: null

         role: endpoints

         namespaces:

           names:

           - istio-system

       relabel_configs:

       - source_labels: [__meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]

         separator: ;

         regex: istio-policy;http-monitoring

         replacement: $1

         action: keep

     - job_name: istio-telemetry

       scrape_interval: 15s

       scrape_timeout: 10s

       metrics_path: /metrics

       scheme: http

       kubernetes_sd_configs:

       - api_server: null

         role: endpoints

         namespaces:

           names:

           - istio-system

       relabel_configs:

       - source_labels: [__meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]

         separator: ;

         regex: istio-telemetry;http-monitoring

         replacement: $1

         action: keep

     - job_name: pilot

       scrape_interval: 15s

       scrape_timeout: 10s

       metrics_path: /metrics

       scheme: http

       kubernetes_sd_configs:

       - api_server: null

         role: endpoints

         namespaces:

           names:

           - istio-system

       relabel_configs:

       - source_labels: [__meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]

         separator: ;

         regex: istio-pilot;http-monitoring

         replacement: $1

         action: keep

     - job_name: galley

       scrape_interval: 15s

       scrape_timeout: 10s

       metrics_path: /metrics

       scheme: http

       kubernetes_sd_configs:

       - api_server: null

         role: endpoints

         namespaces:

           names:

           - istio-system

       relabel_configs:

       - source_labels: [__meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]

         separator: ;

         regex: istio-galley;http-monitoring

         replacement: $1

         action: keep

     - job_name: citadel

       scrape_interval: 15s

       scrape_timeout: 10s

       metrics_path: /metrics

       scheme: http

       kubernetes_sd_configs:

       - api_server: null

         role: endpoints

         namespaces:

           names:

           - istio-system

       relabel_configs:

       - source_labels: [__meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]

         separator: ;

         regex: istio-citadel;http-monitoring

         replacement: $1

         action: keep

     - job_name: kubernetes-pods-istio-secure

       scrape_interval: 15s

       scrape_timeout: 10s

       metrics_path: /metrics

       scheme: https

       kubernetes_sd_configs:

       - api_server: null

         role: pod

         namespaces:

           names: []

       tls_config:

         ca_file: /etc/istio-certs/root-cert.pem

         cert_file: /etc/istio-certs/cert-chain.pem

         key_file: /etc/istio-certs/key.pem

         insecure_skip_verify: true

       relabel_configs:

       - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]

         separator: ;

         regex: "true"

         replacement: $1

         action: keep

       - source_labels: [__meta_kubernetes_pod_annotation_sidecar_istio_io_status, __meta_kubernetes_pod_annotation_istio_mtls]

         separator: ;

         regex: (([^;]+);([^;]*))|(([^;]*);(true))

         replacement: $1

         action: keep

       - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scheme]

         separator: ;

         regex: (http)

         replacement: $1

         action: drop

       - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]

         separator: ;

         regex: (.+)

         target_label: __metrics_path__

         replacement: $1

         action: replace

       - source_labels: [__address__]

         separator: ;

         regex: ([^:]+):(\d+)

         replacement: $1

         action: keep

       - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]

         separator: ;

         regex: ([^:]+)(?::\d+)?;(\d+)

         target_label: __address__

         replacement: $1:$2

         action: replace

       - separator: ;

         regex: __meta_kubernetes_pod_label_(.+)

         replacement: $1

         action: labelmap

       - source_labels: [__meta_kubernetes_namespace]

         separator: ;

         regex: (.*)

         target_label: namespace

         replacement: $1

         action: replace

       - source_labels: [__meta_kubernetes_pod_name]

         separator: ;

         regex: (.*)

         target_label: pod_name

         replacement: $1

         action: replace

4.5. etcd

對於 etcd 叢集一般情況下，為了安全都會開啟 https 證書認證的方式，所以要想讓 Prometheus 訪問到 etcd 叢集的監控資料，就需要提供相應的證書校驗。

由於我們這裡演示環境使用的是 Kubeadm 搭建的叢集，我們可以使用 kubectl 工具去獲取 etcd 啟動的時候使用的證書路徑：

[root@cn-hongkong ~]# kubectl get pod etcd-cn-hongkong.i-j6caps6av1mtyxyofmrw -n kube-system -o yaml

我們可以看到 etcd 使用的證書都對應在節點的 /etc/kubernetes/pki/etcd 這個路徑下面，所以首先我們將需要使用到的證書通過 secret 物件儲存到叢集中去：(在 etcd 執行的節點)

1) 手動獲取etcd資訊

curl --cacert /etc/kubernetes/pki/etcd/ca.crt --cert /etc/kubernetes/pki/etcd/healthcheck-client.crt --key /etc/kubernetes/pki/etcd/healthcheck-client.key https://172.31.182.152:2379/metrics

2) 使用prometheus抓取

kubectl -n monitoring create secret generic etcd-certs --from-file=/etc/kubernetes/pki/etcd/healthcheck-client.crt --from-file=/etc/kubernetes/pki/etcd/healthcheck-client.key --from-file=/etc/kubernetes/pki/etcd/ca.crt

3) 新增values.yaml檔案中kubeEtcd配置

## Component scraping etcd

##

kubeEtcd:

  enabled: true

  ## If your etcd is not deployed as a pod, specify IPs it can be found on

  ##

  endpoints: []

  ## Etcd service. If using kubeEtcd.endpoints only the port and targetPort are used

  ##

  service:

    port: 2379

    targetPort: 2379

    selector:

      component: etcd

  ## Configure secure access to the etcd cluster by loading a secret into prometheus and

  ## specifying security configuration below. For example, with a secret named etcd-client-cert

  ##

  serviceMonitor:

    scheme: https

    insecureSkipVerify: true

    serverName: localhost

    caFile: /etc/prometheus/secrets/etcd-certs/ca.crt

    certFile: /etc/prometheus/secrets/etcd-certs/healthcheck-client.crt

    keyFile: /etc/prometheus/secrets/etcd-certs/healthcheck-client.key

4) 將上面建立的etcd-certs物件配置到prometheus中（特別重要）

    ## Secrets is a list of Secrets in the same namespace as the Prometheus object, which shall be mounted into the Prometheus Pods.

    ## The Secrets are mounted into /etc/prometheus/secrets/. Secrets changes after initial creation of a Prometheus object are not

    ## reflected in the running Pods. To change the secrets mounted into the Prometheus Pods, the object must be deleted and recreated

    ## with the new list of secrets.

    ##

    secrets:

    - etcd-certs

安裝後證書就會出現在prometheus目錄下

 4.6抓取自定義Server

我們需要建一個ServiceMonitor，namespaceSelector：的any:true表示匹配 所有名稱空間下面的具有 app= sscp-transaction這個 label 標籤的 Service。

apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  labels:
    app: sscp-transaction
    release: prometheus-operator
  name: springboot
  namespace: monitoring
spec:
  endpoints:
  - interval: 15s
    path: /actuator/prometheus
    port: health
    scheme: http
  namespaceSelector:
    any: true
#    matchNames:
#    - sscp-dev
  selector:
    matchLabels:
      app: sscp-transaction
#      release: sscp

效果圖：

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