Evaluate the value of the env file vars.

[wfender]

I propose this fix. It does not address the multiline problem cause to me it should be a new feature but at least it will allow to use new line and other stuff like this in env file.

Signed-off-by: Fender William fender.william@gmail.com

Resolves #3527

[shin-]

Thanks @wfender !

Looks like this broke unicode support (see test failures). As far as I can tell, it also misses the point Aanand made here which is that changes to env_file handling should happen upstream in moby/moby first, otherwise we're introducing a confusing discrepancy between Docker and Compose.

[wfender]

Hi @shin-
It wasn't the unicode support but just a warning that I've add ;) and i reduce the scope to evaluate only a double quoted value.

Like many others I'm disappointed that such basic problem could not be solved for so long time.
For moby, the issue is closed and will not be treated despite the many requests.
Unfortunately on the side of moby the discussions about an .env2 file doesn't seem conclusive and i think it's not the place to develop an .env2 file.

So like the 50+ comments I think we could at least evaluate the double quoted values and that will probably help the many people who do not benefit from swarm mode. (docker secret ...) for certificates managment and other kind of variables.
Otherwise if we want the problem to be solved on the docker engine side (and I'll understand that we don't want to create confusion with the engine support ) then why not close this discussion and send back to moby/moby.
Thanks :)

[ijc]

I came across this while doing some PR grooming.

why not close this discussion and send back to moby/moby.

Given what I read above from shin and the linked comment I think this is indeed the right thing to do (although since #3527 (comment) was written I think this is now https://github.com/docker/cli rather than moby/moby since IIRC such things are handled client side).