在Knative中收集度量

Knative支持收集指标的不同流行工具:

• Prometheus
• OpenTelemetry Collector

Grafana 仪表板可用于直接从Prometheus收集的指标。

您还可以设置OpenTelemetry Collector，以便从Knative组件接收度量，并将它们分发给支持OpenTelemetry的其他度量提供程序。

Warning

您不能同时使用OpenTelemetry Collector和Prometheus。 默认的度量后端是Prometheus。 你需要从config-observability Configmap中删除metrics.backend-destination 和 metrics.request-metrics-backend-destination键来启用Prometheus度量。

关于 Prometheus

Prometheus是一个用于收集、聚合时间序列度量和警报的开源工具。 它还可以用于刮除OpenTelemetry Collector，下面将在使用Prometheus时演示这一点。

配置 Prometheus

1. Install the Prometheus Operator by using Helm:

   helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
   helm repo update
   helm install prometheus prometheus-community/kube-prometheus-stack -n default -f values.yaml
   # values.yaml contains at minimum the configuration below
   

   Caution

   You will need to ensure that the helm chart has following values configured, otherwise the ServiceMonitors/Podmonitors will not work.

   kube-state-metrics:
     metricLabelsAllowlist:
       - pods=[*]
       - deployments=[app.kubernetes.io/name,app.kubernetes.io/component,app.kubernetes.io/instance]
   prometheus:
     prometheusSpec:
       serviceMonitorSelectorNilUsesHelmValues: false
       podMonitorSelectorNilUsesHelmValues: false
   

2. Apply the ServiceMonitors/PodMonitors to collect metrics from Knative.

   kubectl apply -f https://raw.githubusercontent.com/knative-sandbox/monitoring/main/servicemonitor.yaml
   

3. Grafana dashboards can be imported from the knative-sandbox repository.

4. If you are using the Grafana Helm Chart with the Dashboard Sidecar enabled, you can load the dashboards by applying the following configmaps.

   kubectl apply -f https://raw.githubusercontent.com/knative-sandbox/monitoring/main/grafana/dashboards.yaml
   

本地访问Prometheus实例

By default, the Prometheus instance is only exposed on a private service named prometheus-operated.

To access the console in your web browser:

1. Enter the command:

   kubectl port-forward -n default svc/prometheus-operated 9090
   

2. Access the console in your browser via http://localhost:9090.

关于 OpenTelemetry

OpenTelemetry是一个针对云原生软件的CNCF可观察性框架，它提供了一组工具、api和sdk。

您可以使用OpenTelemetry来测量、生成、收集和导出遥测数据。 这些数据包括度量、日志和跟踪，您可以通过分析这些数据来了解Knative组件的性能和行为。

OpenTelemetry允许您轻松地将指标导出到多个监视服务，而不需要重新构建或重新配置Knative二进制文件。

理解收集器

收集器提供了一个位置，各种Knative组件可以在其中推送由监视服务保留和收集的指标。

在下面的示例中，您可以使用ConfigMap和Deployment配置单个收集器实例。

Tip

对于更复杂的部署，您可以通过使用OpenTelemetry Operator自动化这些步骤中的一些。

Caution

https://github.com/knative-sandbox/monitoring/tree/main/grafana上的Grafana仪表板不能使用从OpenTelemetry Collector中提取的指标。

设置收集器

1. Create a namespace for the collector to run in, by entering the following command:

   kubectl create namespace metrics
   

   The next step uses the metrics namespace for creating the collector.

2. Create a Deployment, Service, and ConfigMap for the collector by entering the following command:

   kubectl apply -f https://raw.githubusercontent.com/knative/docs/main/docs/serving/observability/metrics/collector.yaml
   

3. Update the config-observability ConfigMaps in the Knative Serving and Eventing namespaces, by entering the follow command:

   kubectl patch --namespace knative-serving configmap/config-observability \
     --type merge \
     --patch '{"data":{"metrics.backend-destination":"opencensus","metrics.request-metrics-backend-destination":"opencensus","metrics.opencensus-address":"otel-collector.metrics:55678"}}'
   kubectl patch --namespace knative-eventing configmap/config-observability \
     --type merge \
     --patch '{"data":{"metrics.backend-destination":"opencensus","metrics.opencensus-address":"otel-collector.metrics:55678"}}'
   

验证收集器设置

1. You can check that metrics are being forwarded by loading the Prometheus export port on the collector, by entering the following command:

   kubectl port-forward --namespace metrics deployment/otel-collector 8889
   

2. Fetch http://localhost:8889/metrics to see the exported metrics.