##### Consul字段设计说明

- 所有数据存在一个名为`blackbox_exporter`的Services项中，每个监控目标为一个子Service。
- 每个Service包含一个Tag，会自动配置为meta中的`module`的值，作为Prometheus自动发现的tags。
- 每个Service使用Meta的kv保存监控目标的明细：`module`，`company`，`project`，`env`，`name`，`instance`，分别表示：监控类型，公司部门，项目，环境，名称，实例url
- **前5个字段合并即为consul的serviceID，作为唯一监控项标识**
- **建议监控类型字段：`meta内的module`，`blackbox-exporter配置中的module`及`Prometheus的job名`使用同一命名。**

### 配置Prometheus

##### 基于Consul实现Prometheus的自动发现功能配置

- 根据Consul每个service的tag来把监控目标关联到Prometheus的JOB。
- 把Consul每个service的Meta的KV关联到Prometheus每个指标的标签。
- 根据每个指标的标签来对监控目标分类，分组，方便管理维护。

**以下配置的同一个job的`job_name`，`module`，`tags`使用同一命名，关联job，module与consul的tags**

参考配置：2XX，4XX，TCP类型的监控，注意JOB名称不要与已有的重复。
```yaml
vi prometheus.yml
#####blackbox_exporter#####
  - job_name: 'http_2xx'
    metrics_path: /probe
    params:
      module: [http_2xx]
    consul_sd_configs:
      - server: 'x.x.x.x:8500'
        token: 'xxx-xxx-xxx-xxx'
        services: ['blackbox_exporter']
        tags: ['http_2xx']
    relabel_configs:
      - source_labels: ["__meta_consul_service_metadata_instance"]
        target_label: __param_target
      - source_labels: ["__meta_consul_service_metadata_company"]
        target_label: company
      - source_labels: ["__meta_consul_service_metadata_env"]
        target_label: env
      - source_labels: ["__meta_consul_service_metadata_name"]
        target_label: name
      - source_labels: ["__meta_consul_service_metadata_project"]
        target_label: project
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: 127.0.0.1:9115
  - job_name: 'http_4xx'
    metrics_path: /probe
    params:
      module: [http_4xx]
    consul_sd_configs:
      - server: 'x.x.x.x:8500'
        token: 'xxx-xxx-xxx-xxx'
        services: ['blackbox_exporter']
        tags: ['http_4xx']
    relabel_configs:
      - source_labels: ["__meta_consul_service_metadata_instance"]
        target_label: __param_target
      - source_labels: ["__meta_consul_service_metadata_company"]
        target_label: company
      - source_labels: ["__meta_consul_service_metadata_env"]
        target_label: env
      - source_labels: ["__meta_consul_service_metadata_name"]
        target_label: name
      - source_labels: ["__meta_consul_service_metadata_project"]
        target_label: project
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: 127.0.0.1:9115
  - job_name: 'tcp_connect'
    metrics_path: /probe
    params:
      module: [tcp_connect]
    consul_sd_configs:
      - server: 'x.x.x.x:8500'
        token: 'xxx-xxx-xxx-xxx'
        services: ['blackbox_exporter']
        tags: ['tcp_connect']
    relabel_configs:
      - source_labels: ["__meta_consul_service_metadata_instance"]
        target_label: __param_target
      - source_labels: ["__meta_consul_service_metadata_company"]
        target_label: company
      - source_labels: ["__meta_consul_service_metadata_env"]
        target_label: env
      - source_labels: ["__meta_consul_service_metadata_name"]
        target_label: name
      - source_labels: ["__meta_consul_service_metadata_project"]
        target_label: project
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: 127.0.0.1:9115
```

### 配置Blackbox_Exporter

参考配置：2XX，4XX，TCP类型的监控，注意模块名称不要与已有的重复。

```
cat blackbox.yml
modules:
  http_2xx:
    prober: http
    http:
      valid_status_codes:
      - 200
      - 301
      - 302
      - 303
      no_follow_redirects: true
      preferred_ip_protocol: ip4
      ip_protocol_fallback: false

  http_4xx:
    prober: http
    http:
      valid_status_codes:
      - 401
      - 403
      - 404
      preferred_ip_protocol: ip4
      ip_protocol_fallback: false

  tcp_connect:
    prober: tcp
```

### 批量导入脚本

在units目录下`instance.list`中写入监控目标的信息：JOB名称，公司/部门，项目，环境，名称，实例url，每行一个，空格分隔。
**注意：前5个字段组合起来必须唯一，作为一个监控项的ID。**
修改units目录下导入脚本中的consul_token和consul_url，保存后执行input.py，即可导入所有监控目标到Consul，并符合Prometheus的自动发现配置。

### 导入Blackbox Exporter Dashboard

- 支持Grafana 8，基于blackbox_exporter 0.19.0设计
- 采用图表+曲线图方式展示TCP，ICMP，HTTPS的服务状态，各阶段请求延时，HTTPS证书信息等
- 优化展示效果，支持监控目标的分组、分类级联展示，多服务同时对比展示。

```
导入ID：9965
详细URL：https://grafana.com/grafana/dashboards/9965
```
### Prometheus 站点监控告警规则
```
- name: Domain
  rules:
  - alert: 站点可用性
    expr: probe_success == 0
    for: 1m
    labels:
      alertype: domain
      severity: critical
    annotations:
      description: "{{$labels.env}}_{{ $labels.name }}({{ $labels.project }})：站点无法访问\n> {{ $labels.instance }}"

  - alert: 站点1h可用性低于80%
    expr: sum_over_time(probe_success[1h])/count_over_time(probe_success[1h]) * 100 < 80
    for: 3m
    labels:
      alertype: domain
      severity: warning
    annotations:
      description: "{{$labels.env}}_{{ $labels.name }}({{ $labels.project }})：站点1h可用性：{{ $value | humanize }}%\n> {{ $labels.instance }}"

  - alert: 站点状态异常
    expr: (probe_success == 0 and probe_http_status_code > 499) or probe_http_status_code == 0
    for: 1m
    labels:
      alertype: domain
      severity: warning
    annotations:
      description: "{{$labels.env}}_{{ $labels.name }}({{ $labels.project }})：站点状态异常：{{$value}}\n> {{ $labels.instance }}"

  - alert: 站点耗时过高
    expr: probe_duration_seconds > 0.5
    for: 2m
    labels:
      alertype: domain
      severity: warning
    annotations:
      description: "{{$labels.env}}_{{ $labels.name }}({{ $labels.project }})：当前站点耗时：{{$value | humanize}}s\n> {{ $labels.instance }}"

  - alert: SSL证书有效期
    expr: (probe_ssl_earliest_cert_expiry-time()) / 3600 / 24 < 15
    for: 2m
    labels:
      alertype: domain
      severity: warning
    annotations:
      description: "{{$labels.env}}_{{ $labels.name }}({{ $labels.project }})：证书有效期剩余{{ $value | humanize }}天\n> {{ $labels.instance }}"
```