prometheus未抓取kubernetes cadvisor端点

Question

我安装了一个minikube kubernetes集群，它是通过prometheus监控的。kubernetes版本是v1.13.4，直接在vm主机上运行(--vm-driver=none)。我在Prometheus配置文件中添加了一个特定的任务，以便抓取cadvisor容器指标。问题是Prometheus无法从cadvisor端点抓取指标。

我在我的prometheus.yml中包含了以下配置

- job_name: 'kubernetes-cadvisor'
  kubernetes_sd_configs:
  - role: node
  relabel_configs:
  - action: labelmap
    regex: __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

但在prometheus targets web UI (http://my_ip:30900/targets)中，我看到"kubernetes-cadvisor“处于关闭状态，并显示以下错误消息

http://kubernetes.default.svc:443/api/v1/nodes/minikube/proxy/metrics/cadvisor: context deadline exceeded

​

​

kubernetes.default.svc:443被认为是默认的集群DNS，可以从pod中访问，但正如预期的那样，我无法在prometheus pod中对其执行ping操作。

幸运的是，我注意到我可以成功地从url获取所有的cadvisor容器指标：

http://my_dashboard_ip_and_port/api/v1/nodes/minikube/proxy/metrics/cadvisor

prometheus pod中的日志是：

kubectl logs prometheus-deployment-6f64ff68f9-8c9xm
level=info ts=2019-03-29T14:33:18.939973334Z caller=main.go:285 msg="no time or size retention was set so using the default time retention" duration=15d
level=info ts=2019-03-29T14:33:18.940326462Z caller=main.go:321 msg="Starting Prometheus" version="(version=2.8.1, branch=HEAD, revision=4d60eb36dcbed725fcac5b27018574118f12fffb)"
level=info ts=2019-03-29T14:33:18.94039376Z caller=main.go:322 build_context="(go=go1.11.6, user=root@bfdd6a22a683, date=20190328-18:04:08)"
level=info ts=2019-03-29T14:33:18.940455316Z caller=main.go:323 host_details="(Linux 4.15.0 #1 SMP Tue Mar 26 02:53:14 UTC 2019 x86_64 prometheus-deployment-6f64ff68f9-8c9xm (none))"
level=info ts=2019-03-29T14:33:18.94050961Z caller=main.go:324 fd_limits="(soft=1048576, hard=1048576)"
level=info ts=2019-03-29T14:33:18.940570849Z caller=main.go:325 vm_limits="(soft=unlimited, hard=unlimited)"
level=info ts=2019-03-29T14:33:18.941555805Z caller=main.go:640 msg="Starting TSDB ..."
level=info ts=2019-03-29T14:33:18.941946171Z caller=web.go:418 component=web msg="Start listening for connections" address=0.0.0.0:9090
level=info ts=2019-03-29T14:33:18.946861683Z caller=main.go:655 msg="TSDB started"
level=info ts=2019-03-29T14:33:18.947193152Z caller=main.go:724 msg="Loading configuration file" filename=/etc/prometheus/prometheus.yml
level=info ts=2019-03-29T14:33:18.948922627Z caller=kubernetes.go:191 component="discovery manager scrape" discovery=k8s msg="Using pod service account via in-cluster config"
level=info ts=2019-03-29T14:33:18.950164896Z caller=kubernetes.go:191 component="discovery manager scrape" discovery=k8s msg="Using pod service account via in-cluster config"
level=info ts=2019-03-29T14:33:18.951281382Z caller=kubernetes.go:191 component="discovery manager scrape" discovery=k8s msg="Using pod service account via in-cluster config"
level=info ts=2019-03-29T14:33:18.952276845Z caller=main.go:751 msg="Completed loading of configuration file" filename=/etc/prometheus/prometheus.yml
level=info ts=2019-03-29T14:33:18.952303937Z caller=main.go:609 msg="Server is ready to receive web requests."

但我不知道如何正确配置Prometheus yml文件，以便能够通过Prometheus获取暴露的指标。

在此之前，非常感谢您。

Answer 1

我认为您可能必须使用HTTPS模式来抓取对HTTP的请求，这似乎保留在您的配置中：

- job_name: 'kubernetes-cadvisor'

  scheme: https

  tls_config:
    ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
  bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token

  kubernetes_sd_configs:
  - role: node

  relabel_configs:
  - action: labelmap
    regex: __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

为了跳过API服务端证书验证，可以在已有的tls_config中添加insecure_skip_verify: true参数

tls_config:
  ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
  insecure_skip_verify: true