Introducing env from: config file

[wlan0]

I believe it is a valid usecase for people where they just import env vars from a local config file.

so, we already have two forms of loading env vars

config:$configMapName and,
secret:$SecretName

what does everyone think about having from: file:env_file, and those values are loaded into the the kubernetes manifest, and then sent to kubernetes. Thoughts?