配置 prometheus-operator 报警规则

原创

张首富1 2020-09-23 15:43:16 博主文章分类：kubernetes ©著作权

©著作权归作者所有：来自51CTO博客作者张首富1的原创作品，请联系作者获取转载授权，否则将追究法律责任

我们安装好 prometheus-operator 之后，打开 prometheus 页面Alerts页面能看到好多报警规则，目前有的还处于报警状态

但是这些报警信息是哪里来的呢？他们应该用怎样的方式通知我们呢？我们知道可以在Prometheus 的配置文件之中指定 AlertManager 实例和报警的 rules 文件，现在我们通过 Operator 部署的呢？我们可以在 Prometheus Dashboard 的 Config 页面下面查看关于 AlertManager 的配置：

alerting:
  alert_relabel_configs:
  - separator: ;
    regex: prometheus_replica
    replacement: $1
    action: labeldrop
  alertmanagers:
  - kubernetes_sd_configs:
    - role: endpoints
      namespaces:
        names:
        - monitoring
    scheme: http
    path_prefix: /
    timeout: 10s
    api_version: v1
    relabel_configs:
    - source_labels: [__meta_kubernetes_service_name]
      separator: ;
      regex: alertmanager-main
      replacement: $1
      action: keep
    - source_labels: [__meta_kubernetes_endpoint_port_name]
      separator: ;
      regex: web
      replacement: $1
      action: keep
rule_files:
- /etc/prometheus/rules/prometheus-k8s-rulefiles-0/*.yaml

上面 alertmanagers 实例的配置我们可以看到是通过角色为 endpoints 的 kubernetes 的服务发现机制获取的，匹配的是服务名为 alertmanager-main，端口名为 web 的 Service 服务，我们查看下 alertmanager-main 这个 Service：

$ kubectl describe -n monitoring svc alertmanager-main
Name:              alertmanager-main
Namespace:         monitoring
Labels:            alertmanager=main
Annotations:       kubectl.kubernetes.io/last-applied-configuration:
                     {"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"alertmanager":"main"},"name":"alertmanager-main","namespace":"...
Selector:          alertmanager=main,app=alertmanager
Type:              ClusterIP
IP:                10.16.131.214
Port:              web  9093/TCP
TargetPort:        web/TCP
Endpoints:         10.103.74.7:9093,10.103.75.9:9093,10.103.76.7:9093
Session Affinity:  ClientIP
Events:            <none>

可以看到服务名正是 alertmanager-main，Port 定义的名称也是 web，符合上面的规则，所以 Prometheus 和 AlertManager 组件就正确关联上了。而对应的报警规则文件位于：/etc/prometheus/rules/prometheus-k8s-rulefiles-0/目录下面所有的 YAML 文件。我们可以进入 Prometheus 的 Pod 中验证下该目录下面是否有 YAML 文件：

$ kubectl exec -it prometheus-k8s-0 /bin/sh -n monitoring
Defaulting container name to prometheus.
Use 'kubectl describe pod/prometheus-k8s-0 -n monitoring' to see all of the containers in this pod.
/prometheus $ ls /etc/prometheus/rules/prometheus-k8s-rulefiles-0/
monitoring-prometheus-k8s-rules.yaml
/prometheus $ cat /etc/prometheus/rules/prometheus-k8s-rulefiles-0/monitoring-pr
ometheus-k8s-rules.yaml
groups:
- name: k8s.rules
  rules:
  - expr: |
      sum(rate(container_cpu_usage_seconds_total{job="kubelet", image!="", container_name!=""}[5m])) by (namespace)
    record: namespace:container_cpu_usage_seconds_total:sum_rate
......

这个 YAML 文件实际上就是我们之前创建的一个 PrometheusRule 文件包含的：

$ cat prometheus-rules.yaml
apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
  labels:
    prometheus: k8s
    role: alert-rules
  name: prometheus-k8s-rules
  namespace: monitoring
spec:
  groups:
  - name: k8s.rules
    rules:
    - expr: |
        sum(rate(container_cpu_usage_seconds_total{job="kubelet", image!="", container_name!=""}[5m])) by (namespace)
      record: namespace:container_cpu_usage_seconds_total:sum_rate

我们这里的 PrometheusRule 的 name 为 prometheus-k8s-rules，namespace 为 monitoring，我们可以猜想到我们创建一个 PrometheusRule 资源对象后，会自动在上面的 prometheus-k8s-rulefiles-0 目录下面生成一个对应的<namespace>-<name>.yaml文件，所以如果以后我们需要自定义一个报警选项的话，只需要定义一个 PrometheusRule 资源对象即可。至于为什么 Prometheus 能够识别这个 PrometheusRule 资源对象呢？这就需要查看我们创建的 prometheus 这个资源对象了，里面有非常重要的一个属性 ruleSelector，用来匹配 rule 规则的过滤器，要求匹配具有 prometheus=k8s 和 role=alert-rules 标签的 PrometheusRule 资源对象，现在明白了吧？

ruleSelector:
  matchLabels:
    prometheus: k8s
    role: alert-rules

所以我们要想自定义一个报警规则，只需要创建一个具有 prometheus=k8s 和 role=alert-rules 标签的 PrometheusRule 对象就行了，比如我们现在添加一个集群节点磁盘使用率操过 88% 就报警。

apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
  labels:
    prometheus: k8s
    role: alert-rules
  name: disk-free-rules
  namespace: monitoring
spec:
  groups:
  - name: disk
    rules:
    - alert: diskFree
      annotations:
        summary: "{{ $labels.job }}  项目实例 {{ $labels.instance }} 磁盘使用率大于 80%"
        description: "{{ $labels.instance }}  {{ $labels.mountpoint }}  磁盘使用率大于80%  (当前的值: {{ $value }}%),请及时处理"
      expr: |
        (1-(node_filesystem_free_bytes{fstype=~"ext4|xfs",mountpoint!="/boot"} / node_filesystem_size_bytes{fstype=~"ext4|xfs",mountpoint!="/boot"}) )*100 > 85
      for: 3m
      labels:
        level: disaster

注意 label 标签一定至少要有 prometheus=k8s 和 role=alert-rules，创建完成后，隔一会儿再去容器中查看下 rules 文件夹：

/etc/prometheus/rules/prometheus-k8s-rulefiles-0 $ ls
monitoring-disk-free-rules.yaml       monitoring-prometheus-k8s-rules.yaml

可以看到我们创建的 rule 文件已经被注入到了对应的 rulefiles 文件夹下面了，证明我们上面的设想是正确的。然后再去 Prometheus Dashboard 的 Alert 页面下面就可以查看到上面我们新建的报警规则了：

配置报警

我们知道了如何去添加一个报警规则配置项，但是这些报警信息用怎样的方式去发送呢？我们知道我们可以通过 AlertManager 的配置文件去配置各种报警接收器，现在我们是通过 Operator 提供的 alertmanager 资源对象创建的组件，应该怎样去修改配置呢？

首先我们将 alertmanager-main 这个 Service 创建一个 ingress，修改完成后我们可以在页面上的 status 路径下面查看 AlertManager 的配置信息:

$ cat ingress.yml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: kube-prometheus
  namespace: monitoring
spec:
  rules:
  - host: prometheus.zsf.com
    http:
      paths:
      - path: /
        backend:
          serviceName: prometheus-k8s
          servicePort: 9090
  - host: grafana.zsf.com
    http:
      paths:
      - path: /
        backend:
          serviceName: grafana
          servicePort: 3000
  - host: alertmanager.zsf.com
    http:
      paths:
      - path: /
        backend:
          serviceName: alertmanager-main
          servicePort: 9093

配置信息其实来自于 alertmanager/alertmanager-secret.yaml

# cat alertmanager/alertmanager-secret.yaml
apiVersion: v1
data:
  alertmanager.yaml: Imdsb2JhbCI6CiAgInJlc29sdmVfdGltZW91dCI6ICI1bSIKInJlY2VpdmVycyI6Ci0gIm5hbWUiOiAibnVsbCIKInJvdXRlIjoKICAiZ3JvdXBfYnkiOgogIC0gImpvYiIKICAiZ3JvdXBfaW50ZXJ2YWwiOiAiNW0iCiAgImdyb3VwX3dhaXQiOiAiMzBzIgogICJyZWNlaXZlciI6ICJudWxsIgogICJyZXBlYXRfaW50ZXJ2YWwiOiAiMTJoIgogICJyb3V0ZXMiOgogIC0gIm1hdGNoIjoKICAgICAgImFsZXJ0bmFtZSI6ICJXYXRjaGRvZyIKICAgICJyZWNlaXZlciI6ICJudWxsIg==
kind: Secret
metadata:
  name: alertmanager-main
  namespace: monitoring
type: Opaque

我们对 alertmanager.yml 文件进行 base 64 反解析

$ echo 'Imdsb2JhbCI6CiAgInJlc29sdmVfdGltZW91dCI6ICI1bSIKInJlY2VpdmVycyI6Ci0gIm5hbWUiOiAibnVsbCIKInJvdXRlIjoKICAiZ3JvdXBfYnkiOgogIC0gImpvYiIKICAiZ3JvdXBfaW50ZXJ2YWwiOiAiNW0iCiAgImdyb3VwX3dhaXQiOiAiMzBzIgogICJyZWNlaXZlciI6ICJudWxsIgogICJyZXBlYXRfaW50ZXJ2YWwiOiAiMTJoIgogICJyb3V0ZXMiOgogIC0gIm1hdGNoIjoKICAgICAgImFsZXJ0bmFtZSI6ICJXYXRjaGRvZyIKICAgICJyZWNlaXZlciI6ICJudWxsIg==' | base64 -d

"global":
  "resolve_timeout": "5m"
"receivers":
- "name": "null"
"route":
  "group_by":
  - "job"
  "group_interval": "5m"
  "group_wait": "30s"
  "receiver": "null"
  "repeat_interval": "12h"
  "routes":
  - "match":
      "alertname": "Watchdog"
    "receiver": "null"

我们可以看到内容和上面查看的配置信息是一致的，所以如果我们想要添加自己的接收器，或者模板消息，我们就可以更改这个文件：

# cat alertmanager.yaml
global:
  resolve_timeout: 5m
receivers:
- name: dingtalk-webhook
  webhook_configs:
  - send_resolved: true
    url: http://dingtalk-webhook:8060/dingtalk/guiji/send
route:
  group_by:
  - job
  group_interval: 5m
  group_wait: 30s
  receiver: dingtalk-webhook
  repeat_interval: 12h
  routes:
  - receiver: dingtalk-webhook
    group_wait: 10s

将上面文件保存为 alertmanager.yaml，然后使用这个文件创建一个 Secret 对象：

# 先将之前的 secret 对象删除
$ kubectl delete secret alertmanager-main -n monitoring
secret "alertmanager-main" deleted
$ kubectl create secret generic alertmanager-main --from-file=alertmanager.yaml -n monitoring
secret "alertmanager-main" created

配置prometheus-operate 钉钉告警

创建 webhook 的配置文件

# vim dingTalk-webhook-configmap.yml
apiVersion: v1
kind: ConfigMap
metadata:
  namespace: monitoring
  name: dingtalk-webhook-config
data:
  config.yml: |
    # Request timeout
    timeout: 5s

    ## Customizable templates path
    templates:
    - /etc/prometheus-webhook-dingtalk/templates/*.tmpl

    ## You can also override default template using `default_message`
    ## The following example to use the 'legacy' template from v0.3.0
    # default_message:
    #   title: '{{ template "legacy.title" . }}'
    #   text: '{{ template "legacy.content" . }}'

    ## Targets, previously was known as "profiles"
    targets:
      guiji:
        url: https://oapi.dingtalk.com/robot/send?access_token=5752a9d10727165d116b883b4e7d312b781a3ed90fefa5d1a8f4d61f06343a27
        message:
          title: '{{ template "ding.link.title" . }}'
          text: '{{ template "ding.link.content" . }}'
        mention:
          all: true
          mobiles: ['18001587880']

创建告警模板配置文件：

# vim dingTalk-webhook-template.yml
apiVersion: v1
kind: ConfigMap
metadata:
  namespace: monitoring
  name: dingtalk-webhook-template
data:
  template.tmpl: |
    {{ define "__subject" }}[{{ .Status | toUpper }}{{ if eq .Status "firing" }}:{{ .Alerts.Firing | len }}{{ end }}] {{ .GroupLabels.SortedPairs.Values     | join " " }} {{ if gt (len .CommonLabels) (len .GroupLabels) }}({{ with .CommonLabels.Remove .GroupLabels.Names }}{{ .Values | join " " }}{{ end     }}){{ end }}{{ end }}
    {{ define "__alertmanagerURL" }}{{ .ExternalURL }}/#/alerts?receiver={{ .Receiver }}{{ end }}

    {{ define "__text_alert_list" }}{{ range . }}
    **Labels**
    {{ range .Labels.SortedPairs }}&gt; - {{ .Name }}: {{ .Value | markdown | html }}
    {{ end }}
    **Annotations**
    {{ range .Annotations.SortedPairs }}&gt; - {{ .Name }}: {{ .Value | markdown | html }}
    {{ end }}
    **Source:** [{{ .GeneratorURL }}]({{ .GeneratorURL }})
    {{ end }}{{ end }}

    {{ define "default.__text_alert_list" }}{{ range . }}
    ---
    **告警级别:** {{ .Labels.severity | upper }}

    **运营团队:** {{ .Labels.team | upper }}

    **触发时间:** {{ dateInZone "2006.01.02 15:04:05" (.StartsAt) "Asia/Shanghai" }}

    **事件信息:**
    {{ range .Annotations.SortedPairs }}&gt; - {{ .Name }}: {{ .Value | markdown | html }}


    {{ end }}

    **事件标签:**
    {{ range .Labels.SortedPairs }}{{ if and (ne (.Name) "severity") (ne (.Name) "summary") (ne (.Name) "team") }}&gt; - {{ .Name }}: {{ .Value |     markdown | html }}
    {{ end }}{{ end }}
    {{ end }}
    {{ end }}
    {{ define "default.__text_alertresovle_list" }}{{ range . }}
    ---
    **告警级别:** {{ .Labels.severity | upper }}

    **运营团队:** {{ .Labels.team | upper }}

    **触发时间:** {{ dateInZone "2006.01.02 15:04:05" (.StartsAt) "Asia/Shanghai" }}

    **结束时间:** {{ dateInZone "2006.01.02 15:04:05" (.EndsAt) "Asia/Shanghai" }}

    **事件信息:**
    {{ range .Annotations.SortedPairs }}&gt; - {{ .Name }}: {{ .Value | markdown | html }}


    {{ end }}

    **事件标签:**
    {{ range .Labels.SortedPairs }}{{ if and (ne (.Name) "severity") (ne (.Name) "summary") (ne (.Name) "team") }}&gt; - {{ .Name }}: {{ .Value |     markdown | html }}
    {{ end }}{{ end }}
    {{ end }}
    {{ end }}

    {{/* Default */}}
    {{ define "default.title" }}{{ template "__subject" . }}{{ end }}
    {{ define "default.content" }}#### \[{{ .Status | toUpper }}{{ if eq .Status "firing" }}:{{ .Alerts.Firing | len }}{{ end }}\] **[{{ index     .GroupLabels "alertname" }}]({{ template "__alertmanagerURL" . }})**
    {{ if gt (len .Alerts.Firing) 0 -}}

    ![警报 图标](https://s2.51cto.com/images/100/blog/error_t.png)
    **====侦测到故障====**
    {{ template "default.__text_alert_list" .Alerts.Firing }}


    {{- end }}

    {{ if gt (len .Alerts.Resolved) 0 -}}
    {{ template "default.__text_alertresovle_list" .Alerts.Resolved }}


    {{- end }}
    {{- end }}

    {{/* Legacy */}}
    {{ define "legacy.title" }}{{ template "__subject" . }}{{ end }}
    {{ define "legacy.content" }}#### \[{{ .Status | toUpper }}{{ if eq .Status "firing" }}:{{ .Alerts.Firing | len }}{{ end }}\] **[{{ index     .GroupLabels "alertname" }}]({{ template "__alertmanagerURL" . }})**
    {{ template "__text_alert_list" .Alerts.Firing }}
    {{- end }}

    {{/* Following names for compatibility */}}
    {{ define "ding.link.title" }}{{ template "default.title" . }}{{ end }}
    {{ define "ding.link.content" }}{{ template "default.content" . }}{{ end }}

创建 webhook 的资源配置清单

# cat dingTalk-webhook-deployment.yml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  namespace: monitoring
  name: dingtalk-webhook
  labels:
    app: dingtalk-webhook
spec:
  selector:
    matchLabels:
      app: dingtalk-webhook
  replicas: 1
  template:
    metadata:
      labels:
        app: dingtalk-webhook
    spec:
      containers:
      - name: dingtalk-webhook
        image: harbor.zsf.com/public/prometheus-webhook-dingtalk
        args:
        - --config.file=/etc/prometheus-webhook-dingtalk/config.yml
        #- --ding.profile=guiji=https://oapi.dingtalk.com/robot/send?access_token=5752a9d10727165d116b883b4e7d312b781a3ed90fefa5d1a8f4d61f06343a27
        ports:
        - containerPort: 8060
          protocol: TCP
        volumeMounts:
        - mountPath: "/etc/prometheus-webhook-dingtalk"
          name: dingtalk-webhook-confing
          subPath: config.yml
        - mountPath: "/etc/prometheus-webhook-dingtalk/templates"
          name: dingtalk-webhook-template
          subPath: template.tmpl
      volumes:
      - name: dingtalk-webhook-confing
        configMap:
          name: dingtalk-webhook-config
      - name: dingtalk-webhook-template
        configMap:
          name: dingtalk-webhook-template
---
apiVersion: v1
kind: Service
metadata:
  namespace: monitoring
  name: dingtalk-webhook
  labels:
    app: dingtalk-webhook
spec:
  selector:
    app: dingtalk-webhook
  ports:
  - name: http
    port: 8060
    targetPort: 8060
    protocol: TCP

然后我们等一会就能查看到报警信息了。