[单master节点k8s部署]20.监控系统构建（五）Alertmanager

prometheus将监控到的异常事件发送给Alertmanager，然后Alertmanager将报警信息发送到邮箱等设备。可以从下图看出，push alerts是由Prometheus发起的。

安装Alertmanager

 config文件

[root@master prometheus]# cat alertmanager-cm.yaml 
kind: ConfigMap
apiVersion: v1
metadata:name: alertmanagernamespace: monitor-sa
data:alertmanager.yml: |-global:resolve_timeout: 1msmtp_smarthost: 'smtp.qq.com:465'smtp_from: '147359****@qq.com'smtp_auth_username: '1123345555'smtp_auth_password: 'pytoinoomgvxiaag'smtp_require_tls: falseroute:group_by: [alertname]group_wait: 10sgroup_interval: 10srepeat_interval: 10mreceiver: default-receiverreceivers:- name: 'default-receiver'email_configs:- to: '[e-mail]'send_resolved: true

随后生效，可以查看configmap清单。 

[root@master prometheus]# kubectl get configmap -n monitor-sa
NAME                DATA   AGE
alertmanager        1      2m8s
kube-root-ca.crt    1      2d10h
prometheus-config   1      36h

报警流程

Prometheus的处理：

• 数据采集：Prometheus Server 定期从配置的监控目标（比如某个 HTTP 接口）采集数据。采集间隔由 scrape_interval 控制。
• Pending 状态：当警报条件首次被满足时，警报会进入“Pending”状态。这是一个预备状态，用于确保问题是持续存在的，而不是暂时性的或偶然的。for 语句在警报规则中定义了需要持续触发该条件多长时间后，警报才会进入下一个状态。
• Firing 状态：如果问题在设定的 for 时间内持续存在，警报状态会转变为“Firing”。这意味着警报被认为是有效的，需要通知到相关人员或系统。
• 报警发送：进入“Firing”状态后，警报信息会发送到 Alertmanager。

Alertmanager 的处理：

• Alertmanager 接收到 FIRING 状态的报警后，会根据报警信息进行分组，并根据配置的 group_wait 延迟一段时间后开始处理报警。

Prometheus报警规则

从上面的流程可以看出来，报警规则是Prometheus设置的。设置一个config文件

[root@master ~]# cat prometheus-alertmanager-cfg.yaml 
kind: ConfigMap
apiVersion: v1
metadata:labels:app: prometheusname: prometheus-confignamespace: monitor-sa
data:prometheus.yml: |rule_files:- /etc/prometheus/rules.ymlalerting:alertmanagers:- static_configs:- targets: ["localhost:9093"]global:scrape_interval: 15sscrape_timeout: 10sevaluation_interval: 1mscrape_configs:- job_name: 'kubernetes-node'kubernetes_sd_configs:- role: noderelabel_configs:- source_labels: [__address__]regex: '(.*):10250'replacement: '${1}:9100'target_label: __address__action: replace- action: labelmapregex: __meta_kubernetes_node_label_(.+)- job_name: 'kubernetes-node-cadvisor'kubernetes_sd_configs:- role:  nodescheme: httpstls_config:ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crtbearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/tokenrelabel_configs:- action: labelmapregex: __meta_kubernetes_node_label_(.+)- target_label: __address__replacement: kubernetes.default.svc:443- source_labels: [__meta_kubernetes_node_name]regex: (.+)target_label: __metrics_path__replacement: /api/v1/nodes/${1}/proxy/metrics/cadvisor- job_name: 'kubernetes-apiserver'kubernetes_sd_configs:- role: endpointsscheme: httpstls_config:ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crtbearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/tokenrelabel_configs:- source_labels: [__meta_kubernetes_namespace, __meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]action: keepregex: default;kubernetes;https- job_name: 'kubernetes-service-endpoints'kubernetes_sd_configs:- role: endpointsrelabel_configs:- source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]action: keepregex: true- source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scheme]action: replacetarget_label: __scheme__regex: (https?)- source_labels: [__meta_kubernetes_service_annotation_prometheus_io_path]action: replacetarget_label: __metrics_path__regex: (.+)- source_labels: [__address__, __meta_kubernetes_service_annotation_prometheus_io_port]action: replacetarget_label: __address__regex: ([^:]+)(?::\d+)?;(\d+)replacement: $1:$2- action: labelmapregex: __meta_kubernetes_service_label_(.+)- source_labels: [__meta_kubernetes_namespace]action: replacetarget_label: kubernetes_namespace- source_labels: [__meta_kubernetes_service_name]action: replacetarget_label: kubernetes_name - job_name: 'kubernetes-pods'kubernetes_sd_configs:- role: podrelabel_configs:- action: keepregex: truesource_labels:- __meta_kubernetes_pod_annotation_prometheus_io_scrape- action: replaceregex: (.+)source_labels:- __meta_kubernetes_pod_annotation_prometheus_io_pathtarget_label: __metrics_path__- action: replaceregex: ([^:]+)(?::\d+)?;(\d+)replacement: $1:$2source_labels:- __address__- __meta_kubernetes_pod_annotation_prometheus_io_porttarget_label: __address__- action: labelmapregex: __meta_kubernetes_pod_label_(.+)- action: replacesource_labels:- __meta_kubernetes_namespacetarget_label: kubernetes_namespace- action: replacesource_labels:- __meta_kubernetes_pod_nametarget_label: kubernetes_pod_name- job_name: 'kubernetes-schedule'scrape_interval: 5sstatic_configs:- targets: ['192.168.40.180:10251']- job_name: 'kubernetes-controller-manager'scrape_interval: 5sstatic_configs:- targets: ['192.168.40.180:10252']- job_name: 'kubernetes-kube-proxy'scrape_interval: 5sstatic_configs:- targets: ['192.168.40.180:10249','192.168.40.181:10249']- job_name: 'kubernetes-etcd'scheme: httpstls_config:ca_file: /var/run/secrets/kubernetes.io/k8s-certs/etcd/ca.crtcert_file: /var/run/secrets/kubernetes.io/k8s-certs/etcd/server.crtkey_file: /var/run/secrets/kubernetes.io/k8s-certs/etcd/server.keyscrape_interval: 5sstatic_configs:- targets: ['192.168.40.180:2379']

data:
  prometheus.yml: |
    rule_files:
    - /etc/prometheus/rules.yml
    alerting:
      alertmanagers:
      - static_configs:
        - targets: ["localhost:9093"]

这一段是基本配置信息，配置Prometheus的文件路径，以及在报警的时候，prometheus是向localhost的9093端口报警，我们将会把alartManager安装到与Prometheus相同的pod，因此使用localhost就可以通信。

  - job_name: 'kubernetes-schedule'
      scrape_interval: 5s
      static_configs:
      - targets: ['192.168.40.180:10251']
    - job_name: 'kubernetes-controller-manager'
      scrape_interval: 5s
      static_configs:
      - targets: ['192.168.40.180:10252']
    - job_name: 'kubernetes-kube-proxy'
      scrape_interval: 5s
      static_configs:
      - targets: ['192.168.40.180:10249','192.168.40.181:10249']
    - job_name: 'kubernetes-etcd'
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/k8s-certs/etcd/ca.crt
        cert_file: /var/run/secrets/kubernetes.io/k8s-certs/etcd/server.crt
        key_file: /var/run/secrets/kubernetes.io/k8s-certs/etcd/server.key
      scrape_interval: 5s
      static_configs:
      - targets: ['192.168.40.180:2379']

相比于CSDN 中的Prometheus 规则，这里新增了一些关于kube-controller和scheduler的规则，但是需要查看具体的开放端口，还要把这里的地址改为本机地址。

但是由于现在controller和scheduler已经不开放metrics端口，所以现在无法通过Prometheus监听。

这里需要额外的精力解决。

 rules.yml: |groups:- name: examplerules:- alert: kube-proxy的cpu使用率大于80%expr: rate(process_cpu_seconds_total{job=~"kubernetes-kube-proxy"}[1m]) * 100 > 80for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.job}}组件的cpu使用率超过80%"- alert:  kube-proxy的cpu使用率大于90%expr: rate(process_cpu_seconds_total{job=~"kubernetes-kube-proxy"}[1m]) * 100 > 90for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.job}}组件的cpu使用率超过90%"- alert: scheduler的cpu使用率大于80%expr: rate(process_cpu_seconds_total{job=~"kubernetes-schedule"}[1m]) * 100 > 80for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.job}}组件的cpu使用率超过80%"- alert:  scheduler的cpu使用率大于90%expr: rate(process_cpu_seconds_total{job=~"kubernetes-schedule"}[1m]) * 100 > 90for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.job}}组件的cpu使用率超过90%"- alert: controller-manager的cpu使用率大于80%expr: rate(process_cpu_seconds_total{job=~"kubernetes-controller-manager"}[1m]) * 100 > 80for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.job}}组件的cpu使用率超过80%"- alert:  controller-manager的cpu使用率大于90%expr: rate(process_cpu_seconds_total{job=~"kubernetes-controller-manager"}[1m]) * 100 > 0for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.job}}组件的cpu使用率超过90%"- alert: apiserver的cpu使用率大于80%expr: rate(process_cpu_seconds_total{job=~"kubernetes-apiserver"}[1m]) * 100 > 80for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.job}}组件的cpu使用率超过80%"- alert:  apiserver的cpu使用率大于90%expr: rate(process_cpu_seconds_total{job=~"kubernetes-apiserver"}[1m]) * 100 > 90for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.job}}组件的cpu使用率超过90%"- alert: etcd的cpu使用率大于80%expr: rate(process_cpu_seconds_total{job=~"kubernetes-etcd"}[1m]) * 100 > 80for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.job}}组件的cpu使用率超过80%"- alert:  etcd的cpu使用率大于90%expr: rate(process_cpu_seconds_total{job=~"kubernetes-etcd"}[1m]) * 100 > 90for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.job}}组件的cpu使用率超过90%"- alert: kube-state-metrics的cpu使用率大于80%expr: rate(process_cpu_seconds_total{k8s_app=~"kube-state-metrics"}[1m]) * 100 > 80for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.k8s_app}}组件的cpu使用率超过80%"value: "{{ $value }}%"threshold: "80%"      - alert: kube-state-metrics的cpu使用率大于90%expr: rate(process_cpu_seconds_total{k8s_app=~"kube-state-metrics"}[1m]) * 100 > 0for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.k8s_app}}组件的cpu使用率超过90%"value: "{{ $value }}%"threshold: "90%"      - alert: coredns的cpu使用率大于80%expr: rate(process_cpu_seconds_total{k8s_app=~"kube-dns"}[1m]) * 100 > 80for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.k8s_app}}组件的cpu使用率超过80%"value: "{{ $value }}%"threshold: "80%"      - alert: coredns的cpu使用率大于90%expr: rate(process_cpu_seconds_total{k8s_app=~"kube-dns"}[1m]) * 100 > 90for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.k8s_app}}组件的cpu使用率超过90%"value: "{{ $value }}%"threshold: "90%"      - alert: kube-proxy打开句柄数>600expr: process_open_fds{job=~"kubernetes-kube-proxy"}  > 600for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.job}}打开句柄数>600"value: "{{ $value }}"- alert: kube-proxy打开句柄数>1000expr: process_open_fds{job=~"kubernetes-kube-proxy"}  > 1000for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.job}}打开句柄数>1000"value: "{{ $value }}"- alert: kubernetes-schedule打开句柄数>600expr: process_open_fds{job=~"kubernetes-schedule"}  > 600for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.job}}打开句柄数>600"value: "{{ $value }}"- alert: kubernetes-schedule打开句柄数>1000expr: process_open_fds{job=~"kubernetes-schedule"}  > 1000for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.job}}打开句柄数>1000"value: "{{ $value }}"- alert: kubernetes-controller-manager打开句柄数>600expr: process_open_fds{job=~"kubernetes-controller-manager"}  > 600for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.job}}打开句柄数>600"value: "{{ $value }}"- alert: kubernetes-controller-manager打开句柄数>1000expr: process_open_fds{job=~"kubernetes-controller-manager"}  > 1000for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.job}}打开句柄数>1000"value: "{{ $value }}"- alert: kubernetes-apiserver打开句柄数>600expr: process_open_fds{job=~"kubernetes-apiserver"}  > 600for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.job}}打开句柄数>600"value: "{{ $value }}"- alert: kubernetes-apiserver打开句柄数>1000expr: process_open_fds{job=~"kubernetes-apiserver"}  > 1000for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.job}}打开句柄数>1000"value: "{{ $value }}"- alert: kubernetes-etcd打开句柄数>600expr: process_open_fds{job=~"kubernetes-etcd"}  > 600for: 2slabels:severity: warnningannotations:description: "{{$labels.instance}}的{{$labels.job}}打开句柄数>600"value: "{{ $value }}"- alert: kubernetes-etcd打开句柄数>1000expr: process_open_fds{job=~"kubernetes-etcd"}  > 1000for: 2slabels:severity: criticalannotations:description: "{{$labels.instance}}的{{$labels.job}}打开句柄数>1000"value: "{{ $value }}"- alert: corednsexpr: process_open_fds{k8s_app=~"kube-dns"}  > 600for: 2slabels:severity: warnning annotations:description: "插件{{$labels.k8s_app}}({{$labels.instance}}): 打开句柄数超过600"value: "{{ $value }}"- alert: corednsexpr: process_open_fds{k8s_app=~"kube-dns"}  > 1000for: 2slabels:severity: criticalannotations:description: "插件{{$labels.k8s_app}}({{$labels.instance}}): 打开句柄数超过1000"value: "{{ $value }}"- alert: kube-proxyexpr: process_virtual_memory_bytes{job=~"kubernetes-kube-proxy"}  > 2000000000for: 2slabels:severity: warnningannotations:description: "组件{{$labels.job}}({{$labels.instance}}): 使用虚拟内存超过2G"value: "{{ $value }}"- alert: schedulerexpr: process_virtual_memory_bytes{job=~"kubernetes-schedule"}  > 2000000000for: 2slabels:severity: warnningannotations:description: "组件{{$labels.job}}({{$labels.instance}}): 使用虚拟内存超过2G"value: "{{ $value }}"- alert: kubernetes-controller-managerexpr: process_virtual_memory_bytes{job=~"kubernetes-controller-manager"}  > 2000000000for: 2slabels:severity: warnningannotations:description: "组件{{$labels.job}}({{$labels.instance}}): 使用虚拟内存超过2G"value: "{{ $value }}"- alert: kubernetes-apiserverexpr: process_virtual_memory_bytes{job=~"kubernetes-apiserver"}  > 2000000000for: 2slabels:severity: warnningannotations:description: "组件{{$labels.job}}({{$labels.instance}}): 使用虚拟内存超过2G"value: "{{ $value }}"- alert: kubernetes-etcdexpr: process_virtual_memory_bytes{job=~"kubernetes-etcd"}  > 2000000000for: 2slabels:severity: warnningannotations:description: "组件{{$labels.job}}({{$labels.instance}}): 使用虚拟内存超过2G"value: "{{ $value }}"- alert: kube-dnsexpr: process_virtual_memory_bytes{k8s_app=~"kube-dns"}  > 2000000000for: 2slabels:severity: warnningannotations:description: "插件{{$labels.k8s_app}}({{$labels.instance}}): 使用虚拟内存超过2G"value: "{{ $value }}"- alert: HttpRequestsAvgexpr: sum(rate(rest_client_requests_total{job=~"kubernetes-kube-proxy|kubernetes-kubelet|kubernetes-schedule|kubernetes-control-manager|kubernetes-apiservers"}[1m]))  > 1000for: 2slabels:team: adminannotations:description: "组件{{$labels.job}}({{$labels.instance}}): TPS超过1000"value: "{{ $value }}"threshold: "1000"   - alert: Pod_restartsexpr: kube_pod_container_status_restarts_total{namespace=~"kube-system|default|monitor-sa"} > 0for: 2slabels:severity: warnningannotations:description: "在{{$labels.namespace}}名称空间下发现{{$labels.pod}}这个pod下的容器{{$labels.container}}被重启,这个监控指标是由{{$labels.instance}}采集的"value: "{{ $value }}"threshold: "0"- alert: Pod_waitingexpr: kube_pod_container_status_waiting_reason{namespace=~"kube-system|default"} == 1for: 2slabels:team: adminannotations:description: "空间{{$labels.namespace}}({{$labels.instance}}): 发现{{$labels.pod}}下的{{$labels.container}}启动异常等待中"value: "{{ $value }}"threshold: "1"   - alert: Pod_terminatedexpr: kube_pod_container_status_terminated_reason{namespace=~"kube-system|default|monitor-sa"} == 1for: 2slabels:team: adminannotations:description: "空间{{$labels.namespace}}({{$labels.instance}}): 发现{{$labels.pod}}下的{{$labels.container}}被删除"value: "{{ $value }}"threshold: "1"- alert: Etcd_leaderexpr: etcd_server_has_leader{job="kubernetes-etcd"} == 0for: 2slabels:team: adminannotations:description: "组件{{$labels.job}}({{$labels.instance}}): 当前没有leader"value: "{{ $value }}"threshold: "0"- alert: Etcd_leader_changesexpr: rate(etcd_server_leader_changes_seen_total{job="kubernetes-etcd"}[1m]) > 0for: 2slabels:team: adminannotations:description: "组件{{$labels.job}}({{$labels.instance}}): 当前leader已发生改变"value: "{{ $value }}"threshold: "0"- alert: Etcd_failedexpr: rate(etcd_server_proposals_failed_total{job="kubernetes-etcd"}[1m]) > 0for: 2slabels:team: adminannotations:description: "组件{{$labels.job}}({{$labels.instance}}): 服务失败"value: "{{ $value }}"threshold: "0"- alert: Etcd_db_total_sizeexpr: etcd_debugging_mvcc_db_total_size_in_bytes{job="kubernetes-etcd"} > 10000000000for: 2slabels:team: adminannotations:description: "组件{{$labels.job}}({{$labels.instance}})：db空间超过10G"value: "{{ $value }}"threshold: "10G"- alert: Endpoint_readyexpr: kube_endpoint_address_not_ready{namespace=~"kube-system|default"} == 1for: 2slabels:team: adminannotations:description: "空间{{$labels.namespace}}({{$labels.instance}}): 发现{{$labels.endpoint}}不可用"value: "{{ $value }}"threshold: "1"- name: 物理节点状态-监控告警rules:- alert: 物理节点cpu使用率expr: 100-avg(irate(node_cpu_seconds_total{mode="idle"}[5m])) by(instance)*100 > 90for: 2slabels:severity: ccriticalannotations:summary: "{{ $labels.instance }}cpu使用率过高"description: "{{ $labels.instance }}的cpu使用率超过90%,当前使用率[{{ $value }}],需要排查处理" - alert: 物理节点内存使用率expr: (node_memory_MemTotal_bytes - (node_memory_MemFree_bytes + node_memory_Buffers_bytes + node_memory_Cached_bytes)) / node_memory_MemTotal_bytes * 100 > 90for: 2slabels:severity: criticalannotations:summary: "{{ $labels.instance }}内存使用率过高"description: "{{ $labels.instance }}的内存使用率超过90%,当前使用率[{{ $value }}],需要排查处理"- alert: InstanceDownexpr: up == 0for: 2slabels:severity: criticalannotations:   summary: "{{ $labels.instance }}: 服务器宕机"description: "{{ $labels.instance }}: 服务器延时超过2分钟"- alert: 物理节点磁盘的IO性能expr: 100-(avg(irate(node_disk_io_time_seconds_total[1m])) by(instance)* 100) < 60for: 2slabels:severity: criticalannotations:summary: "{{$labels.mountpoint}} 流入磁盘IO使用率过高！"description: "{{$labels.mountpoint }} 流入磁盘IO大于60%(目前使用:{{$value}})"- alert: 入网流量带宽expr: ((sum(rate (node_network_receive_bytes_total{device!~'tap.*|veth.*|br.*|docker.*|virbr*|lo*'}[5m])) by (instance)) / 100) > 102400for: 2slabels:severity: criticalannotations:summary: "{{$labels.mountpoint}} 流入网络带宽过高！"description: "{{$labels.mountpoint }}流入网络带宽持续5分钟高于100M. RX带宽使用率{{$value}}"- alert: 出网流量带宽expr: ((sum(rate (node_network_transmit_bytes_total{device!~'tap.*|veth.*|br.*|docker.*|virbr*|lo*'}[5m])) by (instance)) / 100) > 102400for: 2slabels:severity: criticalannotations:summary: "{{$labels.mountpoint}} 流出网络带宽过高！"description: "{{$labels.mountpoint }}流出网络带宽持续5分钟高于100M. RX带宽使用率{{$value}}"- alert: TCP会话expr: node_netstat_Tcp_CurrEstab > 1000for: 2slabels:severity: criticalannotations:summary: "{{$labels.mountpoint}} TCP_ESTABLISHED过高！"description: "{{$labels.mountpoint }} TCP_ESTABLISHED大于1000%(目前使用:{{$value}}%)"- alert: 磁盘容量expr: 100-(node_filesystem_free_bytes{fstype=~"ext4|xfs"}/node_filesystem_size_bytes {fstype=~"ext4|xfs"}*100) > 80for: 2slabels:severity: criticalannotations:summary: "{{$labels.mountpoint}} 磁盘分区使用率过高！"description: "{{$labels.mountpoint }} 磁盘分区使用大于80%(目前使用:{{$value}}%)"

可以看到报警信息有critical和warning两种。这里面的指标都来自于Prometheus监控到的指标。