deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    name: nginx
spec:
  selector:
    matchLabels:
      name: nginx
  template:
    metadata:
      labels:
        name: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.21.6-alpine
        ports:
        - containerPort: 80
###### Mount the config map
        volumeMounts:
          - name: mnt
            mountPath: /usr/share/nginx/html/index.html
            subPath: file-from-cfgmap
      volumes:
      - name: mnt
        configMap:
          name: nginx-cfgmap