Write ConfigMap Value as File

To write a value from a ConfigMap to a file inside a container use a volume mount with a subPath

ConfigMap.yaml

kind: ConfigMap
apiVersion: v1
metadata:
  name: my-config
data:
  appsettings.json: |-
    {
      "ApplicationName": "My Application",
        "OtherSettings" : {
      ...
        }
     }

Deployment.yaml

apiVersion: apps/v1
kind: Deployment
spec:
  template:
    spec:
      volumes:
      - name: config-volume
        configMap:
          name: my-config
      containers:
      - name: MyDeployment
        image: MyImage
        volumeMounts:
          - name: config-volume
            mountPath: /app/Conf/appsettings.json
            subPath: appsettings.json
            readOnly: true

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