Kubernetes系列之kubernetes Prometheus Operator
Operator是由CoreOS公司开发的用来扩展Kubernetes API的特定应用程序控制器，用来创建、配置和管理复杂的有状态应用，例如Mysql、缓存和监控系统。目前CoreOS官方提供了几种Operator的代码实现，其中就包括Prometheus Operator
下图为Prometheus Operator 架构图
Operator作为一个核心的控制器，它会创建Prometheus、ServiceMonitor、alertmanager以及我们的prometheus-rule这四个资源对象，operator会一直监控并维持这四个资源对象的状态，其中创建Prometheus资源对象就是作为Prometheus Server进行监控，而ServiceMonitor就是我们用的exporter的各种抽象（exporter前面文章已经介绍了，就是提供我们各种服务的metrics的工具）Prometheus就是通过ServiceMonitor提供的metrics数据接口把我们数据pull过来的。现在我们监控prometheus不需要每个服务单独创建修改规则。通过直接管理Operator来进行集群的监控。这里还要说一下，一个ServiceMonitor可以通过我们的label标签去匹配集群内部的service，而我们的prometheus也可以通过label匹配多个ServiceMonitor
其中，Operator是核心部分，作为一个控制器而存在，Operator会创建Prometheus、ServiceMonitor、AlertManager及PrometheusRule这4个CRD资源对象，然后一直监控并维持这4个CRD资源对象的状态
- Prometheus 资源对象是作为Prometheus Service存在的
- ServiceMonitor 资源对象是专门提供metrics数据接口的exporter的抽象，Prometheus就是通过ServiceMonitor提供的metrics数据接口去 pull 数据的
- AlerManager 资源对象是对应alertmanager组件
- PrometheusRule 资源对象是被Prometheus实例使用的告警规则文件
CRD简介 全称CustomResourceDefinition，在Kubernetes中一切都可视为资源，在Kubernetes1.7之后增加对CRD自定义资源二次开发能力开扩展Kubernetes API，当我们创建一个新的CRD时，Kubernetes API服务器将为你制定的每个版本创建一个新的RESTful资源路径，我们可以根据该API路径来创建一些我们自己定义的类型资源。CRD可以是命名空间，也可以是集群范围。由CRD的作用域scpoe字段中所制定的，与现有的内置对象一样，删除名称空间将删除该名称中的所有自定义对象
简单的来说CRD是对Kubernetes API的扩展，Kubernetes中的每个资源都是一个API对象的集合，例如yaml文件中定义spec那样，都是对Kubernetes中资源对象的定义，所有的自定义资源可以跟Kubernetes中内建的资源一样使用Kubectl
这样，在集群中监控数据，就变成Kubernetes直接去监控资源对象，Service和ServiceMonitor都是Kubernetes的资源对象，一个ServiceMonitor可以通过labelSelector匹配一类Service，Prometheus也可以通过labelSelector匹配多个ServiceMonitor，并且Prometheus和AlertManager都是自动感知监控告警配置的变化，不需要认为进行reload操作。
安装
Operator是原生支持Prometheus的，可以通过服务发现来监控集群，并且是通用安装。也就是operator提供的yaml文件，基本上在Prometheus是可以直接使用的，需要改动的地方可能就只有几处
#官方下载 (使用官方下载的出现镜像版本不相同请自己找镜像版本)
wget -P /root/ https://github.com/coreos/kube-prometheus/archive/master.zip
unzip master.zip
cd /root/kube-prometheus-master/manifests
prometheus-serviceMonitorKubelet.yaml (这个文件是用来收集我们service的metrics数据的)
不需要修改
cat prometheus-serviceMonitorKubelet.yaml
apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
labels:
k8s-app: kubelet
name: kubelet
namespace: monitoring
spec:
endpoints:
- bearerTokenFile: /var/run/secrets/kubernetes.io/serviceaccount/token
honorLabels: true
interval: 30s
port: https-metrics
scheme: https
tlsConfig:
insecureSkipVerify: true
- bearerTokenFile: /var/run/secrets/kubernetes.io/serviceaccount/token
honorLabels: true
interval: 30s
metricRelabelings:
- action: drop
regex: container_(network_tcp_usage_total|network_udp_usage_total|tasks_state|cpu_load_average_10s)
sourceLabels:
- __name__
path: /metrics/cadvisor
port: https-metrics
scheme: https
tlsConfig:
insecureSkipVerify: true
jobLabel: k8s-app
namespaceSelector: #匹配命名空间，这个代表的意思就是会去匹配kube-system命名空间下，具有k8s-app=kubelet的标签，会将匹配的标签纳入我们prometheus监控中
matchNames:
- kube-system
selector: #这三行是用来匹配我们的service
matchLabels:
k8s-app: kubelet
这里修改完毕后，我们就可以直接创建配置文件
[root@HUOBAN-K8S-MASTER01 manifests]# kubectl apply -f ./
namespace/monitoring unchanged
customresourcedefinition.apiextensions.k8s.io/alertmanagers.monitoring.coreos.com unchanged
customresourcedefinition.apiextensions.k8s.io/podmonitors.monitoring.coreos.com unchanged
customresourcedefinition.apiextensions.k8s.io/prometheuses.monitoring.coreos.com unchanged
customresourcedefinition.apiextensions.k8s.io/prometheusrules.monitoring.coreos.com unchanged
customresourcedefinition.apiextensions.k8s.io/servicemonitors.monitoring.coreos.com unchanged
clusterrole.rbac.authorization.k8s.io/prometheus-operator unchanged
clusterrolebinding.rbac.authorization.k8s.io/prometheus-operator unchanged
deployment.apps/prometheus-operator unchanged
service/prometheus-operator unchanged
serviceaccount/prometheus-operator unchanged
servicemonitor.monitoring.coreos.com/prometheus-operator created
alertmanager.monitoring.coreos.com/main created
secret/alertmanager-main unchanged
service/alertmanager-main unchanged
serviceaccount/alertmanager-main unchanged
servicemonitor.monitoring.coreos.com/alertmanager created
secret/grafana-datasources unchanged
configmap/grafana-dashboard-apiserver unchanged
configmap/grafana-dashboard-controller-manager unchanged
configmap/grafana-dashboard-k8s-resources-cluster unchanged
configmap/grafana-dashboard-k8s-resources-namespace unchanged
configmap/grafana-dashboard-k8s-resources-node unchanged
configmap/grafana-dashboard-k8s-resources-pod unchanged
configmap/grafana-dashboard-k8s-resources-workload unchanged
configmap/grafana-dashboard-k8s-resources-workloads-namespace unchanged
configmap/grafana-dashboard-kubelet unchanged
configmap/grafana-dashboard-node-cluster-rsrc-use unchanged
configmap/grafana-dashboard-node-rsrc-use unchanged
configmap/grafana-dashboard-nodes unchanged
configmap/grafana-dashboard-persistentvolumesusage unchanged
configmap/grafana-dashboard-pods unchanged
configmap/grafana-dashboard-prometheus-remote-write unchanged
configmap/grafana-dashboard-prometheus unchanged
configmap/grafana-dashboard-proxy unchanged
configmap/grafana-dashboard-scheduler unchanged
configmap/grafana-dashboard-statefulset unchanged
configmap/grafana-dashboards unchanged
deployment.apps/grafana configured
service/grafana unchanged
serviceaccount/grafana unchanged
servicemonitor.monitoring.coreos.com/grafana created
clusterrole.rbac.authorization.k8s.io/kube-state-metrics unchanged
clusterrolebinding.rbac.authorization.k8s.io/kube-state-metrics unchanged
deployment.apps/kube-state-metrics unchanged
role.rbac.authorization.k8s.io/kube-state-metrics unchanged
rolebinding.rbac.authorization.k8s.io/kube-state-metrics unchanged
service/kube-state-metrics unchanged
serviceaccount/kube-state-metrics unchanged
servicemonitor.monitoring.coreos.com/kube-state-metrics created
clusterrole.rbac.authorization.k8s.io/node-exporter unchanged
clusterrolebinding.rbac.authorization.k8s.io/node-exporter unchanged
daemonset.apps/node-exporter configured
service/node-exporter unchanged
serviceaccount/node-exporter unchanged
servicemonitor.monitoring.coreos.com/node-exporter created
apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io unchanged
clusterrole.rbac.authorization.k8s.io/prometheus-adapter unchanged
clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader unchanged
clusterrolebinding.rbac.authorization.k8s.io/prometheus-adapter unchanged
clusterrolebinding.rbac.authorization.k8s.io/resource-metrics:system:auth-delegator unchanged
clusterrole.rbac.authorization.k8s.io/resource-metrics-server-resources unchanged
configmap/adapter-config unchanged
deployment.apps/prometheus-adapter configured
rolebinding.rbac.authorization.k8s.io/resource-metrics-auth-reader unchanged
service/prometheus-adapter unchanged
serviceaccount/prometheus-adapter unchanged
clusterrole.rbac.authorization.k8s.io/prometheus-k8s unchanged
clusterrolebinding.rbac.authorization.k8s.io/prometheus-k8s unchanged
prometheus.monitoring.coreos.com/k8s created
rolebinding.rbac.authorization.k8s.io/prometheus-k8s-config unchanged
rolebinding.rbac.authorization.k8s.io/prometheus-k8s unchanged
rolebinding.rbac.authorization.k8s.io/prometheus-k8s unchanged
rolebinding.rbac.authorization.k8s.io/prometheus-k8s unchanged
role.rbac.authorization.k8s.io/prometheus-k8s-config unchanged
role.rbac.authorization.k8s.io/prometheus-k8s unchanged
role.rbac.authorization.k8s.io/prometheus-k8s unchanged
role.rbac.authorization.k8s.io/prometheus-k8s unchanged
prometheusrule.monitoring.coreos.com/prometheus-k8s-rules created
service/prometheus-k8s unchanged
serviceaccount/prometheus-k8s unchanged
servicemonitor.monitoring.coreos.com/prometheus created
servicemonitor.monitoring.coreos.com/kube-apiserver created
servicemonitor.monitoring.coreos.com/coredns created
servicemonitor.monitoring.coreos.com/kube-controller-manager created
servicemonitor.monitoring.coreos.com/kube-scheduler created
servicemonitor.monitoring.coreos.com/kubelet created
当我们部署成功之后，我们可以查看一下crd,yaml文件会自动帮我们创建crd文件。只有我们创建了crd文件，我们的serviceMonitor才会有用
[root@HUOBAN-K8S-MASTER01 manifests]# kubectl get crd
NAME CREATED AT
alertmanagers.monitoring.coreos.com 2019-10-18T08:32:57Z
podmonitors.monitoring.coreos.com 2019-10-18T08:32:58Z
prometheuses.monitoring.coreos.com 2019-10-18T08:32:58Z
prometheusrules.monitoring.coreos.com 2019-10-18T08:32:58Z
servicemonitors.monitoring.coreos.com 2019-10-18T08:32:59Z
其他的资源文件都会部署在一个命名空间下面，在monitoring里面是operator Pod对应的列表
[root@HUOBAN-K8S-MASTER01 manifests]# kubectl get pod -n monitoring
NAME READY STATUS RESTARTS AGE
alertmanager-main-0 2/2 Running 0 11m
alertmanager-main-1 2/2 Running 0 11m
alertmanager-main-2 2/2 Running 0 11m
grafana-55488b566f-g2sm9 1/1 Running 0 11m
kube-state-metrics-ff5cb7949-wq7pb 3/3 Running 0 11m
node-exporter-6wb5v 2/2 Running 0 11m
node-exporter-785rf 2/2 Running 0 11m
node-exporter-7kvkp 2/2 Running 0 11m
node-exporter-85bnh 2/2 Running 0 11m
node-exporter-9vxwf 2/2 Running 0 11m
node-exporter-bvf4r 2/2 Running 0 11m
node-exporter-j6d2d 2/2 Running 0 11m
prometheus-adapter-668748ddbd-d8k7f 1/1 Running 0 11m
prometheus-k8s-0 3/3 Running 1 11m
prometheus-k8s-1 3/3 Running 1 11m
prometheus-operator-55b978b89-qpzfk 1/1 Running 0 11m
其中prometheus和alertmanager采用的StatefulSet，其他的Pod则采用deployment创建
[root@HUOBAN-K8S-MASTER01 manifests]# kubectl get deployments.apps -n monitoring
NAME READY UP-TO-DATE AVAILABLE AGE
grafana 1/1 1 1 12m
kube-state-metrics 1/1 1 1 12m
prometheus-adapter 1/1 1 1 12m
prometheus-operator 1/1 1 1 12m
[root@HUOBAN-K8S-MASTER01 manifests]# kubectl get statefulsets.apps -n monitoring
NAME READY AGE
alertmanager-main 3/3 11m
prometheus-k8s 2/2 11m
#其中prometheus-operator是我们的核心文件，它是监控我们prometheus和alertmanager的文件
现在创建完成后我们还无法直接访问prometheus
[root@HUOBAN-K8S-MASTER01 manifests]# kubectl get svc -n monitoring |egrep "prometheus|grafana|alertmanage"
alertmanager-main ClusterIP 10.96.226.38 <none> 9093/TCP 3m55s
alertmanager-operated ClusterIP None <none> 9093/TCP,9094/TCP,9094/UDP 3m10s
grafana ClusterIP 10.97.175.234 <none> 3000/TCP 3m53s
prometheus-adapter ClusterIP 10.96.43.155 <none> 443/TCP 3m53s
prometheus-k8s ClusterIP 10.105.75.186 <none> 9090/TCP 3m52s
prometheus-operated ClusterIP None <none> 9090/TCP 3m
prometheus-operator ClusterIP None <none> 8080/TCP 3m55s
由于默认的yaml文件svc采用的是ClusterIP，我们无法进行访问。这里我们可以使用ingress进行代理，或者使用node-port临时访问。我这里就修改一下svc，使用node-port进行访问
#我这里使用edit进行修改，或者修改yaml文件apply下即可
kubectl edit svc -n monitoring prometheus-k8s
#注意修改的svc是prometheus-k8s因为这个有clusterIP
kubectl edit svc -n monitoring grafana
kubectl edit svc -n monitoring alertmanager-main
#三个文件都需要修改，不要修改错了。都是修改有clusterIP的
...
type: NodePort #将这行修改为NodePort
prometheus-k8s、grafana和alertmanager-main都是只修改type=clusterIP这行
修改完毕后，我们在查看svc，就会发现这几个都包含node端口了，接下来在任意集群节点访问即可
[root@HUOBAN-K8S-MASTER01 manifests]# kubectl get svc -n monitoring |egrep "prometheus|grafana|alertmanage"
alertmanager-main NodePort 10.96.226.38 <none> 9093:32477/TCP 13m
alertmanager-operated ClusterIP None <none> 9093/TCP,9094/TCP,9094/UDP 12m
grafana NodePort 10.97.175.234 <none> 3000:32474/TCP 13m
prometheus-adapter ClusterIP 10.96.43.155 <none> 443/TCP 13m
prometheus-k8s NodePort 10.105.75.186 <none> 9090:32489/TCP 13m
prometheus-operated ClusterIP None <none> 9090/TCP 12m
prometheus-operator ClusterIP None <none> 8080/TCP 13m
接下来我们查看prometheus的Ui界面
[root@HUOBAN-K8S-MASTER01 manifests]# kubectl get svc -n monitoring |grep prometheus-k8s
prometheus-k8s NodePort 10.105.75.186 <none> 9090:32489/TCP 19m
[root@HUOBAN-K8S-MASTER01 manifests]# hostname -i
172.16.17.191
我们访问的集群172.16.17.191:32489
这里kube-controller-manager和kube-scheduler并管理的目标，其他的都有。这里的就是和官方yaml文件里面定义的有关系
配置文件解释
# vim prometheus-serviceMonitorKubeScheduler.yaml
apiVersion: monitoring.coreos.com/v1 #kubectl get crd里面包含的，不进行修改
kind: ServiceMonitor
metadata:
labels:
k8s-app: kube-scheduler
name: kube-scheduler #定义的名称
namespace: monitoring
spec:
endpoints:
- interval: 30s
port: http-metrics #这里定义的就是在svc上的端口名称
jobLabel: k8s-app
namespaceSelector: #表示匹配哪一个命名空间，配置any:true则回去所有命名空间中查询
matchNames:
- kube-system
selector: #这里大概意思就是匹配kube-system命名空间下具有k8s-app=kube-scheduler标签的svc
matchLabels:
k8s-app: kube-scheduler
