What is the equivalent of envFrom when creating task definitions for AWS ECS?

Kubernetes has a very useful attribute envFrom which can reference secrets (link and all key-value pairs are automatically mapped to the container’s env variable.

I’ve looked through the documentation on container definition, the container secrets, can only be referenced by name and valueFrom (using a specific key or it will be in JSON format – AFAIK).

Am I missing something, or do I have to painstakingly add all the variables and secrets one by one in the definition?