concept envFrom in category knative

This is an excerpt from Manning's book Knative in Action MEAP V04. Login to get full access to this book.

But there are actually two alternative ways of injecting environment variables: --env-from / envFrom and valueFrom. What they have in common is that you don’t provide the values of variables directly, and envFrom goes further and even does away with providing a name. In both cases the values come from either a ConfigMap or a Secret.

If you are so inclined, it’s possible to do this in YAML with envFrom.

Listing 3.31. Using envFrom to stamp out environment variables

apiVersion: serving.knative.dev/v1
kind: Configuration
metadata:
  name: values-from-example
spec:
  template:
    spec:
      containers:
      - image: example.com/an/image
        envFrom:
        - configMapRef:
            name: example-configmap
        - secretRef:
            name: example-secret