configmap.yaml

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  creationTimestamp: null
  name: test
spec:
  replicas: 1
  template:
    metadata:
      creationTimestamp: null
      labels:
        service: test
    spec:
      containers:
        image: test
        name: test
        ports:
        - containerPort: 80
        resources:
          limits:
            memory: 300Mi
          requests:
            memory: 100Mi
        volumeMounts:
        - name: "config"
          mountPath: "/<existing folder>/<file1>"
          subPath: "<file1>"
        - name: "config"
          mountPath: "/<existing folder>/<file2>"
          subPath: "<file2>"
      restartPolicy: Always
      volumes:
        - name: "config"
          configMap:
            name: "config"
      restartPolicy: Always
status: {}

subPath is now deprecated

so, what is the best practice to mount single file into existing directory？

@abdennour why do you think it's deprecated?

i am pretty sure that i put that comment based on the official documentation of k8s.

@abdennour can you link to it?

No, it is not deprecated. Documents on VolumeMounts: https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#volumes-1

@abdennour kubernetes v1.24 subPath is still not deprecated...

Be aware that using subPath has the downside of not updating the file when ConfigMap changes.

Be aware that using subPath has the downside of not updating the file when ConfigMap changes.

Unless you restart the pod