k8s集群监控【使用Helm一键安装Prometheus Operator】

介绍

首先我们先来了解下Prometheus-Operator的架构图：

上图是Prometheus-Operator官方提供的架构图，其中Operator是最核心的部分，作为一个控制器，他会去创建Prometheus、ServiceMonitor、AlertManager以及PrometheusRule4个CRD资源对象，然后会一直监控并维持这4个资源对象的状态。

其中创建的prometheus这种资源对象就是作为Prometheus Server存在，而ServiceMonitor就是exporter的各种抽象，exporter前面我们已经学习了，是用来提供专门提供metrics数据接口的工具，Prometheus就是通过ServiceMonitor提供的metrics数据接口去 pull 数据的，当然alertmanager这种资源对象就是对应的AlertManager的抽象，而PrometheusRule是用来被Prometheus实例使用的报警规则文件。

这样我们要在集群中监控什么数据，就变成了直接去操作 Kubernetes 集群的资源对象了，是不是方便很多了。上图中的 Service 和 ServiceMonitor 都是 Kubernetes 的资源，一个 ServiceMonitor 可以通过 labelSelector 的方式去匹配一类 Service，Prometheus 也可以通过 labelSelector 去匹配多个ServiceMonitor。

https://github.com/helm/charts/tree/master/stable/prometheus-operator 

• 查看stable/prometheus-operator的默认值 

helm inspect values stable/prometheus-operator

• 将默认配置导出，备用

helm inspect values stable/prometheus-operator > prometheus-operator.yaml

• 提前将配置中涉及到的镜像下载好

#!/bin/sh
docker pull hub.deri.org.cn/k8s_monitor/alertmanager:v0.19.0
docker tag hub.deri.org.cn/k8s_monitor/alertmanager:v0.19.0 quay.io/prometheus/alertmanager:v0.19.0
docker rmi hub.deri.org.cn/k8s_monitor/alertmanager:v0.19.0

docker pull hub.deri.org.cn/k8s_monitor/ghostunnel:v1.4.1 
docker tag hub.deri.org.cn/k8s_monitor/ghostunnel:v1.4.1 squareup/ghostunnel:v1.4.1
docker rmi hub.deri.org.cn/k8s_monitor/ghostunnel:v1.4.1 

docker pull hub.deri.org.cn/k8s_monitor/kube-webhook-certgen:v1.0.0 
docker tag hub.deri.org.cn/k8s_monitor/kube-webhook-certgen:v1.0.0  jettech/kube-webhook-certgen:v1.0.0
docker rmi hub.deri.org.cn/k8s_monitor/kube-webhook-certgen:v1.0.0 

docker pull hub.deri.org.cn/k8s_monitor/prometheus-operator:v0.34.0
docker tag hub.deri.org.cn/k8s_monitor/prometheus-operator:v0.34.0 quay.io/coreos/prometheus-operator:v0.34.0
docker rmi hub.deri.org.cn/k8s_monitor/prometheus-operator:v0.34.0

docker pull hub.deri.org.cn/k8s_monitor/configmap-reload:v0.0.1
docker tag hub.deri.org.cn/k8s_monitor/configmap-reload:v0.0.1 quay.io/coreos/configmap-reload:v0.0.1
docker rmi pull hub.deri.org.cn/k8s_monitor/configmap-reload:v0.0.1

docker pull hub.deri.org.cn/k8s_monitor/prometheus-config-reloader:v0.34.0
docker tag hub.deri.org.cn/k8s_monitor/prometheus-config-reloader:v0.34.0 quay.io/coreos/prometheus-config-reloader:v0.34.0
docker rmi hub.deri.org.cn/k8s_monitor/prometheus-config-reloader:v0.34.0

docker pull hub.deri.org.cn/k8s_monitor/hyperkube:v1.12.1
docker tag hub.deri.org.cn/k8s_monitor/hyperkube:v1.12.1 k8s.gcr.io/hyperkube:v1.12.1
docker rmi  hub.deri.org.cn/k8s_monitor/hyperkube:v1.12.1

docker pull hub.deri.org.cn/k8s_monitor/prometheus:v2.13.1
docker tag hub.deri.org.cn/k8s_monitor/prometheus:v2.13.1 quay.io/prometheus/prometheus:v2.13.1
docker rmi hub.deri.org.cn/k8s_monitor/prometheus:v2.13.1

docker pull hub.deri.org.cn/k8s_monitor/kube-state-metrics:v1.8.0
docker tag hub.deri.org.cn/k8s_monitor/kube-state-metrics:v1.8.0 quay.io/coreos/kube-state-metrics:v1.8.0
docker rmi hub.deri.org.cn/k8s_monitor/kube-state-metrics:v1.8.0

docker pull hub.deri.org.cn/k8s_monitor/node-exporter:v0.18.1
docker tag hub.deri.org.cn/k8s_monitor/node-exporter:v0.18.1 quay.io/prometheus/node-exporter:v0.18.1
docker rmi hub.deri.org.cn/k8s_monitor/node-exporter:v0.18.1

docker pull hub.deri.org.cn/k8s_monitor/k8s-sidecar:0.1.20
docker tag hub.deri.org.cn/k8s_monitor/k8s-sidecar:0.1.20 kiwigrid/k8s-sidecar:0.1.20
docker rmi hub.deri.org.cn/k8s_monitor/k8s-sidecar:0.1.20

docker pull hub.deri.org.cn/k8s_monitor/grafana:6.4.2
docker tag hub.deri.org.cn/k8s_monitor/grafana:6.4.2 grafana/grafana:6.4.2
docker rmi hub.deri.org.cn/k8s_monitor/grafana:6.4.2

• 用默认配置安装，指定了name、namespace等信息

helm install stable/prometheus-operator  --name prometheus-operator --namespace monitoring -f prometheus-operator.yaml --set grafana.adminPassword=admin

• 查看pod运行情况

kubectl get pod -n monitoring

• 修改Grafana的service类型为NodePort，便于访问测试

kubectl edit svc prometheus-operator-grafana -n monitoring

通过下面命令，查看绑定宿主机的端口 ，访问测试密码安装时指定了admin/admin

kubectl get svc -n monitoring

• 卸载

helm delete prometheus-operator

helm delete --purge prometheus-operator

Prometheus-Operator安装时会去创建Prometheus、ServiceMonitor、AlertManager以及PrometheusRule4个CRD资源对象，卸载时一并删掉

kubectl delete crd prometheuses.monitoring.coreos.com
kubectl delete crd prometheusrules.monitoring.coreos.com
kubectl delete crd servicemonitors.monitoring.coreos.com
kubectl delete crd podmonitors.monitoring.coreos.com
kubectl delete crd alertmanagers.monitoring.coreos.com

• 修改prometheus-operator.yaml，配置ingress

例如AlterManager配置，默认情况enabled: false修改成true，hosts: []填入alterManager的域名
alertmanager:
  ingress:
    enabled: true
    hosts: ["alert.deri.com"]

• 修改prometheus-operator.yaml，配置数据持久化

例如AlterManager，默认如下，是被注释掉的，取消注释，并填入你的storageClassName
    storage: {}
    # volumeClaimTemplate:
    #   spec:
    #     storageClassName: gluster
    #     accessModes: ["ReadWriteOnce"]
    #     resources:
    #       requests:
    #         storage: 50Gi
    #   selector: {}

alertmanager:
  alertmanagerSpec:
    storage: 
      volumeClaimTemplate:
        spec:
          storageClassName: nfs-client
          accessModes: ["ReadWriteOnce"]
          resources:
            requests:
              storage: 5Gi
        selector: {}

其它配置可以在默认配置prometheus-operator.yaml中查看并修改。

问题一：【摘自https://github.com/helm/charts/tree/master/stable/prometheus-operator】

KubeProxy【改完重启kubelet、docker服务】

The metrics bind address of kube-proxy is default to 127.0.0.1:10249 that prometheus instances cannot access to. You should expose metrics by changing metricsBindAddress field value to 0.0.0.0:10249 if you want to collect them.

Depending on the cluster, the relevant part config.conf will be in ConfigMap kube-system/kube-proxy or kube-system/kube-proxy-config. For example:

kubectl -n kube-system edit cm kube-proxy

apiVersion: v1
data:
  config.conf: |-
    apiVersion: kubeproxy.config.k8s.io/v1alpha1
    kind: KubeProxyConfiguration
    # ...
    # metricsBindAddress: 127.0.0.1:10249
    metricsBindAddress: 0.0.0.0:10249
    # ...
  kubeconfig.conf: |-
    # ...
kind: ConfigMap
metadata:
  labels:
    app: kube-proxy
  name: kube-proxy
  namespace: kube-system

问题二： 

在不同环境安装时发现结果不一样，所有配置都一样，可能原因：

由于上述是通过helm安装的，首先通过命令"helm repo list"检查源是否一致；

通过"helm search | grep prometheus"查看    CHART VERSION    APP VERSION  是否一致；

如果不一致通过"helm repo update"更新一下就可以了。