Custom metrics exporter deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    run: custom-metric-sd
  name: custom-metric-sd
  namespace: default
spec:
  replicas: 1
  selector:
    matchLabels:
      run: custom-metric-sd
  template:
    metadata:
      labels:
        run: custom-metric-sd
    spec:
      containers:
      - command: ["./sd-dummy-exporter"]
        args:
        - --use-new-resource-model=true
        - --use-old-resource-model=false
        - --metric-name=custom-metric
        - --metric-value=40
        - --pod-name=$(POD_NAME)
        - --namespace=$(NAMESPACE)
        image: us-docker.pkg.dev/google-samples/containers/gke/sd-dummy-exporter:v0.3.0
        name: sd-dummy-exporter
        resources:
          requests:
            cpu: 100m
        env:
        # save Kubernetes metadata as environment variables for use in metrics
        - name: POD_NAME
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: metadata.name
        - name: NAMESPACE
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: metadata.namespace