k8s-prometheus-adapter deployment avg cpu usage / deployment limit ratio rule (based on cAdvisor and kube-state-metrics)

hpa.yaml

kind: HorizontalPodAutoscaler
apiVersion: autoscaling/v2beta1
metadata:
  name: {{ HPA }}
spec:
  scaleTargetRef:
    apiVersion: extensions/v1beta1
    kind: Deployment
    name: {{ DEPLOYMENT }}
  minReplicas: 2
  maxReplicas: 10
  metrics:
  - type: Object
    object:
      metricName: deployment_cpu_usage_limit_ratio
      target:
        apiVersion: extensions/v1beta1
        kind: Deployment
        name: {{ DEPLOYMENT }}
      targetValue: 0.5

k8s-prometheus-adapter.yaml

rules:
  default: false
  custom:
  - seriesQuery: kube_deployment_created{namespace!="",deployment!=""}
    resources:
      overrides:
        deployment:
          resource: deployment
        namespace:
          resource: namespace
    metricsQuery: |-
      avg(
        avg(label_replace(kube_pod_owner{namespace=~"<< index .LabelValuesByName "namespace" >>"}, "replicaset", "$1", "owner_name", "(.*)")) by (namespace, replicaset, pod)
        * on (namespace, replicaset) group_left(deployment) avg(label_replace(kube_replicaset_owner{namespace=~"<< index .LabelValuesByName "namespace" >>",owner_name=~"<< index .LabelValuesByName "deployment" >>"}, "deployment", "$1", "owner_name", "(.*)")) by (namespace, replicaset, deployment)
        * on (namespace, pod) group_left
        label_replace(
          (
            avg(
              rate(container_cpu_system_seconds_total{namespace=~"<< index .LabelValuesByName "namespace" >>",pod_name!="",container_name!~"(|POD)"}[2m])
            + rate(container_cpu_user_seconds_total{namespace=~"<< index .LabelValuesByName "namespace" >>",pod_name!="",container_name!~"(|POD)"}[2m])
            ) by (namespace,pod_name)
            /
            avg(
              sum(
                label_replace(
                  label_replace(kube_pod_container_resource_limits_cpu_cores{namespace=~"<< index .LabelValuesByName "namespace" >>"}, "pod_name", "$1", "pod", "(.*)"),
                  "container_name", "$1", "container", "(.*)"
                )
              ) by (namespace, pod_name, container_name)
            ) by (namespace, pod_name)
          ),
          "pod", "$1",
          "pod_name", "(.*)"
        )
      ) by (namespace, deployment)
    name:
      as: deployment_cpu_usage_limit_ratio
      matches: ^kube_deployment_created$