Updated Prometheus query

[denis-jdsouza]

Hi arjunrn,
Amazing project, really appreciates your work on this HPA.

I would like to make a few contributions to your project, beginning with the below changes:

Compatibility Changes

• Updated Prometheus query to be compatible with a newer version of Kubernetes
• Tested on the following environment:
  • Kubernetes v1.17 with Docker v19.03
  • Prometheus v2.20
  • Kube-state-metrics v1.8

Grafana Screenshot:

Prometheus config snippet:

- job_name: kube-state-metrics
  honor_timestamps: true
  scrape_interval: 15s
  scrape_timeout: 10s
  metrics_path: /metrics
  scheme: http
  static_configs:
  - targets:
    - kube-state-metrics.kube-system.svc.cluster.local:8080

- job_name: kubernetes-cadvisor
  honor_timestamps: true
  scrape_interval: 15s
  scrape_timeout: 10s
  metrics_path: /metrics
  scheme: https
  kubernetes_sd_configs:
  - role: node
  bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
  tls_config:
    ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
    insecure_skip_verify: false
  relabel_configs:
  - separator: ;
    regex: __meta_kubernetes_node_label_(.+)
    replacement: $1
    action: labelmap
  - separator: ;
    regex: (.*)
    target_label: __address__
    replacement: kubernetes.default.svc:443
    action: replace
  - source_labels: [__meta_kubernetes_node_name]
    separator: ;
    regex: (.+)
    target_label: __metrics_path__
    replacement: /api/v1/nodes/${1}/proxy/metrics/cadvisor
    action: replace