add .env support

[glensc]

Looks like meli doesn't support .env file.

➔ cat .env
APP_VERSION=1

➔ cat docker-compose.yml
version: "3"

services:
  app:
    image: nginx:${APP_VERSION}

➔ meli -up

	 service=app error=originalErr:: invalid reference format
ThisErr::  :unable to pull image nginx:${APP_VERSION}➔

ps: there's \n missing from error, my bash prompt does not start on new line due that

[komuw]

hi @glensc

currently meli only contains the subset of feature that I use daily.
I normally don't use .env files in my compose files.

But it looks like you do use, so I'll try and add them; I'll ping you on this issue if/when I do manage to add that feature.

[komuw]

@glensc hi,
I'm trying to be super minimal with the things that I add to meli.
Which is to say, I do not want to add features unless I know they are super critical for someone; so, are .env files super critical to you or a nice to have feature?
thanks.

[glensc]

i'm not using this tool. but if i would, the .env loading is blocker and i can't use for all purposes without other modifications :)

[komuw]

commentary(mostly to self);

• we could read all .env files
• parse env vars from them ,

  meli/parsedotenv.go

  Line 32 in fead852

  func parsedotenv(r io.Reader) env {

• read compose file into a sting and call os.expandEnv on it + the parsed envs akin to;

  meli/format.go

  Line 66 in fead852

  volume = os.ExpandEnv(volume)