5.11. 使用 Prometheus 配置内置监控

流程

1. 在 Operator SDK 项目中，取消注释 config/default/kustomization.yaml 文件中的以下行：

   ../prometheus

   Copy to Clipboard Toggle word wrap

2. 创建自定义控制器类，以便从 Operator 发布其他指标。以下示例将 widgets 和 widgetFailures 收集器声明为全局变量，然后将它们注册到控制器的软件包中的 init() 函数：

   例 5.6. controllers/memcached_controller_test_metrics.go 文件

   package controllers
   
   import (
   	"github.com/prometheus/client_golang/prometheus"
   	"sigs.k8s.io/controller-runtime/pkg/metrics"
   )
   
   
   var (
       widgets = prometheus.NewCounter(
           prometheus.CounterOpts{
               Name: "widgets_total",
               Help: "Number of widgets processed",
           },
       )
       widgetFailures = prometheus.NewCounter(
           prometheus.CounterOpts{
               Name: "widget_failures_total",
               Help: "Number of failed widgets",
           },
       )
   )
   
   func init() {
       // Register custom metrics with the global prometheus registry
       metrics.Registry.MustRegister(widgets, widgetFailures)
   }

   Copy to Clipboard Toggle word wrap

3. 记录这些收集器来自 main 控制器类中协调循环的任何部分，这决定了指标的业务逻辑：

   例 5.7. controllers/memcached_controller.go 文件

   func (r *MemcachedReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
   	...
   	...
   	// Add metrics
   	widgets.Inc()
   	widgetFailures.Inc()
   
   	return ctrl.Result{}, nil
   }

   Copy to Clipboard Toggle word wrap

4. 构建和推送 Operator：

   $ make docker-build docker-push IMG=<registry>/<user>/<image_name>:<tag>

   Copy to Clipboard Toggle word wrap

5. 部署 Operator：

   $ make deploy IMG=<registry>/<user>/<image_name>:<tag>

   Copy to Clipboard Toggle word wrap

6. 创建角色和角色绑定定义，以允许 OpenShift Container Platform 集群的 Prometheus 实例提取 Operator 的服务监控。

   必须分配角色，以便服务帐户具有提取命名空间指标的权限：

   例 5.8. config/prometheus/role.yaml 角色

   apiVersion: rbac.authorization.k8s.io/v1
   kind: ClusterRole
   metadata:
     name: prometheus-k8s-role
     namespace: <operator_namespace>
   rules:
     - apiGroups:
         - ""
       resources:
         - endpoints
         - pods
         - services
         - nodes
         - secrets
       verbs:
         - get
         - list
         - watch

   Copy to Clipboard Toggle word wrap

   例 5.9. config/prometheus/rolebinding.yaml 角色绑定

   apiVersion: rbac.authorization.k8s.io/v1
   kind: ClusterRoleBinding
   metadata:
     name: prometheus-k8s-rolebinding
     namespace: memcached-operator-system
   roleRef:
     apiGroup: rbac.authorization.k8s.io
     kind: ClusterRole
     name: prometheus-k8s-role
   subjects:
     - kind: ServiceAccount
       name: prometheus-k8s
       namespace: openshift-monitoring

   Copy to Clipboard Toggle word wrap

7. 为部署的 Operator 应用角色和绑定：

   $ oc apply -f config/prometheus/role.yaml

   Copy to Clipboard Toggle word wrap

   $ oc apply -f config/prometheus/rolebinding.yaml

   Copy to Clipboard Toggle word wrap

8. 为您要提取的命名空间设置标签，为该命名空间启用 OpenShift 集群监控：

   $ oc label namespace <operator_namespace> openshift.io/cluster-monitoring="true"

   Copy to Clipboard Toggle word wrap