Prometheus做API接口监控

运维过程中，很多时候，业务应用会出现假死的情况，应用进程正常，但是无法提供服务，此时监控进程没有任何意义，就需要监控接口

接口监控的方法很多，可以用链路监控，可以写脚本进行监控

由于监控整体采用的是prometheus，所以这里就直接用blackbox_exporter来做接口的监控

blackbox_exporter可以通过http、https、dns、tcp、ICMP对target进行探测，dns、tcp、ICMP都相对简单，我这边主要是要监控一个登录接口，所以要用https来进行探测，具体配置方法如下

部署blockbox_exporter

# 创建blackbox_exporter的目录
cd /usr/local/blackbox_exporter
# 下载blackbox_exporter的包
wget https://github.com/prometheus/blackbox_exporter/releases/download/v0.19.0/blackbox_exporter-0.19.0.linux-amd64.tar.gz
# 解压
tar -zxvf blackbox_exporter-0.19.0.linux-amd64.tar.gz
# 重命名
mv blackbox_exporter-0.19.0.linux-amd64.tar.gz blackbox_exporter

用systemd管理blackbox_exporter

cat > /etc/systemd/system/blackbox_exporter.service << "EOF"
[Unit]
Description=Blackbox Exporter
Wants=network-online.target
After=network-online.target

[Service]
User=root
ExecStart=/usr/local/blackbox_exporter/blackbox_exporter/blackbox_exporter --config.file=/usr/local/blackbox_exporter/blackbox_exporter/blackbox.yml 
Restart=on-failure

[Install]
WantedBy=default.target
EOF

对于blackbox_exporter管理的话，还有很多方法，你可以直接nohup后台启动，也可以通过supervisor进行启动，我习惯用systemd进行管理

然后添加开机自启动

systemctl daemon-reload
systemctl enable blackbox_exporter
systemctl start blackbox_exporter

因为没指定日志输出，所以是输出到message日志中

默认带的blacbox.yml只是个最简单配置，不能满足需求，所以配置blackbox.yml中，添加一个模块

modules:
  xhj_login:  # 模块名称,prometheus配置文件中要匹配
    prober: http    # 协议
    timeout: 30s  # 超时时间
    http:   # 模块的采集协议
      method: POST    # http请求的方法
      preferred_ip_protocol: "ip4"   # 使用的ipv4协议
      headers:   # 配置post请求的header头
        Content-Type: application/json
      body: ''{"mobile": "13572801829", "password": "ZWB123wyl"}'' # post请求参数

配置完成后，保存blackbox.yml，启动blackbox_exporter

systemctl start blackbox_exporter
systemctl status blackbox_exporter
● blackbox_exporter.service - Blackbox Exporter
   Loaded: loaded (/etc/systemd/system/blackbox_exporter.service; enabled; vendor preset: disabled)
   Active: active (running) since Tue 2022-01-04 21:33:28 CST; 6s ago
 Main PID: 24679 (blackbox_export)
    Tasks: 7
   Memory: 1.9M
   CGroup: /system.slice/blackbox_exporter.service
           └─24679 /data/prometheus/blackbox_exporter/blackbox_exporter/blackbox_exporter --config.file=/data/prometheus/blackbox_exporter/blackbox_exporter/blackbox....

Jan 04 21:33:28  systemd[1]: Started Blackbox Exporter.
Jan 04 21:33:28  blackbox_exporter[24679]: level=info ts=2022-01-04T13:33:28.173Z caller=main.go:224 msg="Starting blackbox_exporter" version="(v...33d1ed0)"
Jan 04 21:33:28  blackbox_exporter[24679]: level=info ts=2022-01-04T13:33:28.173Z caller=main.go:225 build_context="(go=go1.16.4, user=root@2b025...2:56:44)"
Jan 04 21:33:28  blackbox_exporter[24679]: level=info ts=2022-01-04T13:33:28.173Z caller=main.go:237 msg="Loaded config file"
Jan 04 21:33:28  blackbox_exporter[24679]: level=info ts=2022-01-04T13:33:28.174Z caller=main.go:385 msg="Listening on address" address=:9115
Jan 04 21:33:28  blackbox_exporter[24679]: level=info ts=2022-01-04T13:33:28.174Z caller=tls_config.go:191 msg="TLS is disabled." http2=false
Hint: Some lines were ellipsized, use -l to show in full.

配置prometheus

# blackbox
  - job_name: "blackbox"
    metrics_path: /probe
    params:
      module: [xhj_login]
    static_configs:
      - targets:
        - https://xxx.aaa.com/api/pc/user/login/password
    relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [_param_target]
        target_label: instance
      - target_label: __address__
        replacement: 172.17.0.1:9115
    ……省略
    ……省略

配置完成后，保存，热加载prometheus配置文件

curl -X POST http://localhost:9090/-/reload

加载完成后，通过prometheus的UI查看下targets

 

此时其实可以通过被请求端的日志就可以看到blackbox_exporter发起的请求了，我们也可以通过curl请求blackbox_exporter来进行查看

# 注意这里用&符号链接多个参数，需要转义
curl http://172.17.0.1:9115/probe?target=https://xxx.aaa.com/api/pc/user/login/password\&module=xhj_login\&debug=true
# 查看返回结果
Logs for the probe:
ts=2022-01-04T14:10:32.979231489Z caller=main.go:320 module=xhj_login target=https://xxx.aaa.com/api/pc/user/login/password level=info msg="Beginning probe" probe=http timeout_seconds=30
ts=2022-01-04T14:10:32.979411891Z caller=http.go:335 module=xhj_login target=https://xxx.aaa.com/api/pc/user/login/password level=info msg="Resolving target address" ip_protocol=ip4
ts=2022-01-04T14:10:32.986112778Z caller=http.go:335 module=xhj_login target=https://xxx.aaa.com/api/pc/user/login/password level=info msg="Resolved target address" ip=1.1.1.1
ts=2022-01-04T14:10:32.986225541Z caller=client.go:251 module=xhj_login target=https://xxx.aaa.com/api/pc/user/login/password level=info msg="Making HTTP request" url=https://1.1.1.1/api/pc/user/login/password host=xxx.aaa.com
ts=2022-01-04T14:10:33.05701057Z caller=main.go:130 module=xhj_login target=https://xxx.aaa.com/api/pc/user/login/password level=info msg="Received HTTP response" status_code=200
ts=2022-01-04T14:10:33.057095911Z caller=main.go:130 module=xhj_login target=https://xxx.aaa.com/api/pc/user/login/password level=info msg="Response timings for roundtrip" roundtrip=0 start=2022-01-04T22:10:32.986352765+08:00 dnsDone=2022-01-04T22:10:32.986352765+08:00 connectDone=2022-01-04T22:10:32.992658409+08:00 gotConn=2022-01-04T22:10:33.038333687+08:00 responseStart=2022-01-04T22:10:33.056951457+08:00 tlsStart=2022-01-04T22:10:32.992701614+08:00 tlsDone=2022-01-04T22:10:33.038235019+08:00 end=2022-01-04T22:10:33.057074505+08:00
ts=2022-01-04T14:10:33.057187486Z caller=main.go:320 module=xhj_login target=https://xxx.aaa.com/api/pc/user/login/password level=info msg="Probe succeeded" duration_seconds=0.077883376

可以看到，http_status_code 200,probe_success为1，访问正常

添加告警

创建rules

groups:
- name: blackbox_networks_stats
  rules:
  - alert: PC登录接口故障
    expr: probe_success == 0
    for: 1m
    labels:
      severity: critical
    annotations:
      summary: "PC登录接口出现故障，无法正常登录，请及时查看！"
      description: "PC登录接口出现故障，无法正常登录，请及时查看！"

创建完成后，热加载prometheus配置，然后查看prometheus的rules

Grafana添加监控图标

监控配置完，必须得配个可视化仪表盘，直接用5345模板导入

仪表盘中显示接口状态、是否使用SSL、包括SSL证书过期时间、接口状态码、接口请求时间和DNS解析时间

我们是如何做到对所有 API 异常请求实时监控的 ?