Why am I getting error trying to mount a directory onto a file?

I have this prometheus deployment manifest file: to create prometheus deployment

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: prometheus
  namespace: monitoring
  labels:
    app: prometheus
spec:
  replicas: 1
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
    type: RollingUpdate
  selector:
    matchLabels:
      app: prometheus
  template:
    metadata:
      labels:
        app: prometheus
      annotations:
        prometheus.io/scrape: "true"
        prometheus.io/port: "9090"
    spec:
      nodeSelector:
        boardType: aarch64
      initContainers:
      - name: prometheus-data-permission-setup
        image: busybox
        command: ["/bin/chmod","-R","777", "/data"]
        volumeMounts:
        - name: prometheus-data
          mountPath: /data
      containers:
      - name: prometheus
        image: rycus86/prometheus:latest
        imagePullPolicy: IfNotPresent
        args:
          - '--storage.tsdb.path=/data'
          - '--config.file=/etc/prometheus/prometheus.yml'
        command:
        - /bin/prometheus
        ports:
        - name: web
          containerPort: 9090
        volumeMounts:
        - name: config-volume
          mountPath: /etc/prometheus/prometheus.yml
          subPath: prometheus.yml
        - name: prometheus-data
          mountPath: /data
          readOnly: false
        resources:
          requests:
            cpu: "250m"
            ephemeral-storage: "4Gi"
          limits:
            memory: "200Mi"
            cpu: "500m"
            ephemeral-storage: "20Gi"
      restartPolicy: Always
      securityContext: {}
      terminationGracePeriodSeconds: 30
      volumes:
      - name: config-volume
        configMap:
          name: prometheus-config
      - name: prometheus-data
        hostPath:
          path: /data
          type: Directory
      serviceAccountName: prometheus

but this error that "trying to mount a directory onto a file "

```
Events:
Type

volumeMount based on configMap actually creates the files for the data keys. You don't need the filename in the mountPath or the subPath
`$ cat

Ref:

• https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap/

StackExchange DevOps Q#13970, answer score: 2