blackbox

一、简介

1. 白盒监控：监控主机的资源用量、容器的运行状态、数据库中间件的运行数据、自动发现 Kubernetes 集群中的资源等等，这些都是支持业务和服务的基础设施，通过白盒能够了解其内部的实际运行状态，通过对监控指标的观察能够预判可能出现的问题，从而对潜在的不确定因素进行优化
2. 黑盒监控：以用户的身份测试服务的外部可见性，常见的黑盒监控包括HTTP 探针、TCP 探针 等用于检测站点或者服务的可访问性，以及访问效率等

二、blackbox exporter

1. Blackbox Exporter是prometheus社区提供的官方黑盒监控解决方案
2. 允许用户通过：HTTP、HTTPS、DNS、TCP以及ICMP的方式对网络进行探测

 

三、实现监控

注意事项：部署prometheus时切记开启配置的自动热更新，否则需要进行手动更新

1、通过configmap提供配置文件，一起创建deployment、service、configmap
apiVersion: v1
kind: ConfigMap
metadata:
  name: blackbox-config
  namespace: kube-mon
data:
  blackbox.yml: |-
    modules:
      http_2xx:  # http 检测模块  Blockbox-Exporter 中所有的探针均是以 Module 的信息进行配置
        prober: http
        timeout: 10s
        http:
          valid_http_versions: ["HTTP/1.1", "HTTP/2"]   
          valid_status_codes: [200]  # 这里最好作一个返回状态码，在grafana作图时，有明示---陈刚注释。
          method: GET
          preferred_ip_protocol: "ip4"
      http_post_2xx: # http post 监测模块
        prober: http
        timeout: 10s
        http:
          valid_http_versions: ["HTTP/1.1", "HTTP/2"]
          method: POST
          preferred_ip_protocol: "ip4"
      tcp_connect:  # TCP 检测模块
        prober: tcp
        timeout: 10s
      dns:  # DNS 检测模块
        prober: dns
        dns:
          transport_protocol: "tcp"  # 默认是 udp
          preferred_ip_protocol: "ip4"  # 默认是 ip6
          query_name: "kubernetes.default.svc.cluster.local"
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: blackbox
  namespace: kube-mon
spec:
  selector:
    matchLabels:
      app: blackbox
  template:
    metadata:
      labels:
        app: blackbox
    spec:
      containers:
      - image: prom/blackbox-exporter:v0.16.0
        name: blackbox
        args:
        - --config.file=/etc/blackbox_exporter/blackbox.yml # ConfigMap 中的配置文件
        - --log.level=error  # 错误级别控制
        ports:
        - containerPort: 9115
        volumeMounts:
        - name: config
          mountPath: /etc/blackbox_exporter
      volumes:
      - name: config
        configMap:
          name: blackbox-config
---
apiVersion: v1
kind: Service
metadata:
  name: blackbox
  namespace: kube-mon
spec:
  selector:
    app: blackbox
  ports:
  - port: 9115
    targetPort: 9115

2、添加blackbox的job配置：DNS探测配置
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
  namespace: kube-mon
data:
  prometheus.yml: |
    global:
      scrape_interval: 15s
      scrape_timeout: 15s
    scrape_configs:
    - job_name: 'prometheus'
      static_configs:
      - targets: ['localhost:9090']
      
    - job_name: "kubernetes-service-dns"
      metrics_path: /probe # 不是 metrics，是 probe
      params:
        module: [dns] # 使用 DNS 模块
      static_configs:
      - targets:
        - kube-dns.kube-system:53  # 不要省略端口号
      relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: blackbox:9115  # 服务地址，和上面的 Service 定义保持一致

3、添加blackbox的job配置：添加HTTP探测：可用于ingress及service的探测
- job_name: 'kubernetes-http-services'
  metrics_path: /probe
  params:
    module: [http_2xx]  # 使用定义的http模块
  kubernetes_sd_configs:
  - role: service  # service 类型的服务发现
  relabel_configs:
  # 只有service的annotation中配置了 prometheus.io/http_probe=true 的才进行发现
  - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_http_probe]
    action: keep
    regex: true
  - source_labels: [__address__]
    target_label: __param_target
  - target_label: __address__
    replacement: blackbox:9115
  - source_labels: [__param_target]
    target_label: instance
  - action: labelmap
    regex: __meta_kubernetes_service_label_(.+)
  - source_labels: [__meta_kubernetes_namespace]
    target_label: kubernetes_namespace
  - source_labels: [__meta_kubernetes_service_name]
    target_label: kubernetes_name


- job_name: 'kubernetes-ingresses'
  metrics_path: /probe
  params:
    module: [http_2xx]  # 使用定义的http模块
  kubernetes_sd_configs:
  - role: ingress  # ingress 类型的服务发现
  relabel_configs:
  # 只有ingress的annotation中配置了 prometheus.io/http_probe=true的才进行发现
  - source_labels: [__meta_kubernetes_ingress_annotation_prometheus_io_http_probe]
    action: keep
    regex: true
  - source_labels: [__meta_kubernetes_ingress_scheme,__address__,__meta_kubernetes_ingress_path]
    regex: (.+);(.+);(.+)
    replacement: ${1}://${2}${3}
    target_label: __param_target
  - target_label: __address__
    replacement: blackbox:9115
  - source_labels: [__param_target]
    target_label: instance
  - action: labelmap
    regex: __meta_kubernetes_ingress_label_(.+)
  - source_labels: [__meta_kubernetes_namespace]
    target_label: kubernetes_namespace
  - source_labels: [__meta_kubernetes_ingress_name]
    target_label: kubernetes_name

4、如果需要对service的黑盒做自定义配置，可以参考一下案例
- source_labels: [__meta_kubernetes_service_name, __meta_kubernetes_namespace, __meta_kubernetes_service_annotation_prometheus_io_http_probe_port, __meta_kubernetes_service_annotation_prometheus_io_http_probe_path]
  action: replace
  target_label: __param_target
  regex: (.+);(.+);(.+);(.+)
  replacement: $1.$2:$3$4

5、对应的service的annotation部分需要添加如下配置
annotation:
  prometheus.io/http-probe: "true"
  prometheus.io/http-probe-port: "8080"
  prometheus.io/http-probe-path: "/healthz"

参考文件：

prometheus配置文件参考： https://github.com/prometheus/prometheus/blob/master/documentation/examples/prometheus-kubernetes.yml

blackbox配置文件参考地址：https://github.com/prometheus/blackbox_exporter/blob/master/example.yml