10-k8s-configmap-env-vol.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: mycfgmap
data:
  # property-like keys; each key maps to a simple value
  env: dev

  # file-like keys
  dest.properties: |
    Q_INPUT=InputQ
    Q_OUTPUT=OutputQ
  
  debug.properties: |
    TracerMode=always
    LogLevel=INFO
---
apiVersion: v1
kind: Pod
metadata:
  name: mypod
spec:
  containers:
  - name: mycontainer
    image: nginx
    resources:
      limits:
        memory: "128Mi"
        cpu: "500m"
    ports:
      - containerPort: 80
    env:
    # Define the environment variable
      - name: ENV
        valueFrom:
          configMapKeyRef:
            name: mycfgmap # The ConfigMap this value comes from.
            key: env # The key to fetch.
    volumeMounts:
      - mountPath: /config
        name: config-vol
        readOnly: true
  volumes:
  # You set volumes at the Pod level, then mount them into containers inside that Pod
    - name: config-vol
      configMap:
        # Provide the name of the ConfigMap you want to mount.
        name: mycfgmap
        # An array of keys from the ConfigMap to create as files
        items:
          - key: "dest.properties"
            path: "dest.properties"
          - key: "debug.properties"
            path: "debug.properties"